Center for Civil Engineering Earthquake Research CCEER

University of Nevada, Reno 1

CCEERCenter for Civil Engineering Earthquake Research

2 Center for Civil Engineering Earthquake Research

The Center for Civil Engineering Earthquake Research (CCEER) at the University of Nevada, Reno was formally established in 1984. Early research efforts were devoted to testing full-scale bridges in the field. But since the completion of the high-bay structures laboratory in the Harry Reid Engineering Laboratory in 1992, a set of high performance shake tables have been used to study a range of structural and geotechnical systems. In 2014, a new Earthquake Engineering Laboratory was completed, giving the facility a total of more than 17,000 square feet of strong floor (tie-down) space.

Today CCEER comprises four research laboratories: two in geotechnical engineering and two in structural engineering, including the Large-Scale Structures Laboratory and the new Earthquake Engineering Laboratory. Almost 20 academic, research, and administrative faculty are affiliated with the Center, and about 30 doctoral and masters students are engaged in research projects under the Centers umbrella. Research funding between 2004 and 2013 averaged about $4.9 million per year. In its 30-year history CCEER has published more than 200 technical reports which describe the results of these activities. Through these and other publications, the Center has become well known for its work in advancing seismic safety, particularly in the area of highway bridges.

The Earthquake Engineering Laboratory is a member of the NSF Funded George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) through September 2014. With the Centers shared-use policies, research is carried out for federal and state agencies, the private sector and non-profit organizations. In addition to highway bridges, the Centers research efforts include the study of non-structural components in buildings, seismic isolation of buildings, and alternative construction materials.

CONTENTSLetters ........................................................................1History ........................................................................3Facilities .....................................................................8Accomplishments - Research ................................11Accomplishments - Education & Outreach .......... 21Grants and Contracts .............................................. 23Membership and Affiliations .................................. 26CCEER Publications ................................................. 27Doctoral Students ................................................... 33 Center Personnel .................................................... 35

FOREWORD


FRONT COVER: Interior View of Earthquake Engineering Laboratory, 2014.

INSIDE FRONT COVER: Instrumenting a Model of a Three-Span Curved Bridge and Trucks in the Large-Scale Structures Laboratory, 2011.

Editing and Layout by Kelly Doyle, Center for Civil Engineering Earthquake Research Graphic Design by Claudia Ortega-Lukas, Office of Marketing & Communications Copyright 2014, by the University of Nevada, Reno. All rights reserved. Reproduction with attribution is permitted.


LETTERS

Ian Buckle, Professor and Director, CCEERThe earthquake engineering program here at the University of Nevada, Reno is one of the finest in the country and perhaps the world. Housed within the Center for Civil

Engineering Earthquake Research, this program has a long history of innovative work particularly in the experimental simulation of earthquake effects. Over the years, notable improvements have been made in the seismic safety of our built environment and of our highway infrastructure in particular. When the Center was twenty-five years old in 2009, we marked the occasion

by publishing a short report summarizing our history and accomplishments. Today, five years later, we have updated this report to celebrate not only 30 years of advancing seismic safety but also the opening of our new, state-of-the-art, Earthquake Engineering Laboratory. It is also an opportunity to acknowledge those who have made this achievement possible. For it is true that our success is due to the efforts of many people ranging from the early academics who pioneered the program to todays entrepreneurial faculty, from first class graduate students to innovative lab personnel, from the department office to the deans office, and from the office of sponsored projects to the presidents office. It also includes our sponsors, both federal and state, who have either funded the unique equipment in our laboratories, or our cutting-edge research, or both. Without the support of NSF, NEES, FHWA, FEMA, MCEER, Caltrans and NDOT1 we would not be where we are today. This is also true of NIST and DOE2, who together funded more than 80% of our new Earthquake Engineering Laboratory, and of the University, its friends and alumni who contributed the remaining 20%.A 30th birthday is an appropriate moment to pause and take stock to look back and see where we have come from

1 NSF: National Science Foundation; NEES: George E. Brown Jr. Network for Earthquake Engineering Simulation; FHWA: Federal Highway Administration; FEMA: Federal Emergency Management Agency; MCEER: Multidisciplinary Center for Extreme Events Research; Caltrans: California Department of Transportation; NDOT: Nevada Department of Transportation.

2 NIST: National Institute of Standards and Technology; DOE: US Department of Energy.

and to look forward and recognize the challenges that still lie ahead. From the quick-release testing of Ramp 13 in the I-80/580 Interchange in 1974, to the shake table testing of a three-span, curved bridge, loaded with six trucks to the point of collapse in 2011, we have indeed come a long way. But there is still a long way to go before we can say we are safe from earthquakes. On behalf of the Center I am asking all our friends, colleagues, and sponsors to join with us as we move forward to meet this challenge head-on.

E. Manos Maragakis, Dean, College of EngineeringThe 30th anniversary of the Center for Civil Engineering Earthquake Research comes during a milestone year for the College of Engineering and our internationally recognized

structural engineering program, as we open a new lab that will significantly improve our research capabilities, enhance the experience of our students and increase our worldwide reputation.This Center exemplifies the vision of the College of Engineering, which aims to achieve measurable national recognition for our globally competitive education programs, state-of-the-art

research activities, and high-quality community outreach. Thanks to the focus, dedication, and hard work of its faculty and staff, the Center has expanded steadily over the past 30 years, and its growth brings millions of dollars of research funding into Nevada. Earthquake engineering research is vital to the safety and well-being of the millions of people around the world who live in seismically active regions, including Nevadans, and the College of Engineering has educated engineers with key positions in academia, federal and state agencies, and private industry.The Centers new Earthquake Engineering Laboratory combined with our Large-Scale Structures Laboratory comprise the biggest, most versatile earthquake engineering facility in the United States, according to NIST, and possibly the largest University-based facility of its kind in the world. Funding for the latest expansion came after a rigorous competitive process in which our faculty demonstrated their ability to compete with the best researchers nationwide. These impressive facilities will enable researchers to conduct


LETTERS

unique ground-breaking experiments and continue to push the fields of structural and geotechnical engineering toward ever safer, more resilient structures. A number of our past projects have demonstrated this commitment to unique research, including the curved bridge project, which was the first large-scale seismic simulation of a curved bridge, and the grand challenge project for nonstructural systems, which moved the focus from structural systems to equally important, but often overlooked, nonstructural systems.Our expanded facilities also pave the way for continued growth in our Ph.D. program in civil and environmental engineering. Over the past decade, our program has grown by more than 50 percent, and our excellent faculty and one-of-a-kind laboratory space will continue to attract the brightest graduate students. As we look toward the future, the Center continues to serve a critical need for the state of Nevada and the nation and continues to excel in all of its activities. I am proud of its success, I look forward to its bright future, and I offer my heartfelt congratulations and best wishes for 30 more years of excellence.

Ahmad Itani, Chair, Department of Civil and Environmental EngineeringThe evolution of engineering is intimately coupled with the emerging needs and challenges encountered by the human race. From building and improving our infrastructure to accelerating our pace of innovation, the engineering profession has flourished and continues to do so through

its impact on the prosperity and well-being of mankind. In this regard, protection against extreme events, including earthquakes, is particularly challenging. The seismic behavior of our buildings and bridges is complex not only because of the erratic nature of earthquakes but because of the nonlinear behavior of construction materials. Everyday experiences of structural engineers cannot

be relied upon to counter the extreme loads produced by earthquakes. These are extraordinary circumstances and many aspects of structural response during seismic events have yet to be discovered. Laboratory studies are a fundamental part of earthquake engineering research, and must be pursued. Only through rigorous research into structural response under extreme loads can the well-being

of mankind be assured. Over the past thirty years, the Center for Civil Engineering Earthquake Research (CCEER) has made significant strides in placing itself in an ever stronger position to contribute to the nations efforts in earthquake risk reduction. The Center is nationally and internationally known for its pioneering work, and I am proud of the quality of the research produced by the Center, its faculty, staff, and graduate students. As the department celebrates its 120 years (established in 1894), we are thankful to the founders of CCEER, Prof. Bruce M. Douglas and Prof. M. Saiid Saiidi, and to the current director Prof. Ian G. Buckle, who have worked diligently to ensure the continued growth of the Center. Their vision and dedication have made the Center and department the respected research organization that it is today. Along with the faculty, staff, and students, the department and university enjoy a national and international reputation. Scholars and graduate students from around the world come to the University of Nevada, Reno to learn and share our experience in experimental earthquake engineering. I would like to take this opportunity to thank our research sponsors, particularly the National Science Foundation, the Federal Highway Administration, the Nevada Department of Transportation, and the California Department of Transportation. Also, the unwavering support of the university administration, President Marc Johnson, Provost Kevin Carman, Vice President Mridul Gautam, and Dean E. Manos Maragakis, is sincerely appreciated and acknowledged.


Pre-1984The teaching of earthquake engineering in the Civil Engineering Department began long before the establishment of CCEER. With strong encouragement from Professor George Housner of the California Institute of Technology and founder of the modern science of earthquake engineering, Professors Bruce Douglas and Alan Ryall of the Nevada Seismological Laboratory began a collaboration in 1967 to introduce the discipline of earthquake engineering to Nevada by establishing such a program at the University of Nevada, Reno. In 1968, a graduate course in Dynamics of Structures, including the earthquake response of structures, was initiated as a Special Projects course. This course appeared for the first time in the University of Nevada, Reno Catalog in 1970. Also in 1968, Douglas and Ryall initiated a course in Earthquake Engineering jointly sponsored with the Geology Department. It appeared in the University Catalog in 1971 and has been taught regularly ever since. In addition to establishing a teaching program, Douglas and Ryall also collaborated for more than a decade on earthquake engineering research projects. Their early work focused on engineering seismology and their later work on seismic risk in Nevada and California. They worked largely in the field because the capital cost of building and equipping a laboratory on campus could not be justified at the time. In 1974, the first funded research contract on the earthquake performance of bridges was obtained from the Federal Highway Administration with James D. Cooper as the contract manager. The experiment was conducted on Ramp 13 in the Reno spaghetti bowl, which is the southbound exit from I-80 east to US 395 south (now I-580 south). It is a six-span slab-and-steel girder bridge. Relatively high amplitude lateral vibrations were generated by the pullback and quick release method, where cables and a D-8 Caterpillar Tractor were employed to cause the initial deformation (Fig. 1). Traffic induced vibrations were used to excite the vertical motions. Relevant dynamic properties of this structure were determined by studying these motions for use in earthquake design. It was the first field test of a highway bridge undertaken by the faculty. The graduate student was Harlan Fricke. With the cooperation of the Nevada Department of Transportation (NDOT), four additional field experiments were undertaken during this period. The next field test was conducted on the Rose Creek Interchange on I-80 near Winnemucca, Nevada. That bridge was a 400 ft long five-span reinforced concrete box girder. Its in-situ earthquake

dynamic properties were studied using the previously described pullback and quick release method. Around the same time, traffic induced vibrations were used to investigate a variable depth composite steel girder bridge on I-80 near Wells, NV. Another field experiment was conducted on the Cold Stream Interchange on US 395 near Bordertown, NV. That bridge was a two-span concrete box with a single concrete pier. The purpose of testing that structure was to pioneer a new method of generating very high amplitude earthquake-like lateral loads using large hydraulic rams. When this was successfully completed, the new experimental technology was employed during another field experiment at Rose Creek with a large crew of graduate students. Except for the first test, all of these early field studies were funded by the National Science Foundation (NSF) with Dr. Jack Scalzi as the program manager. Over a period of two decades Dr. Scalzi and NDOT were major factors in the success of the Center. It was during this pre-1984 period that the Civil Engineering Department began focusing its efforts on building a critical mass of faculty in the areas of structural, geotechnical, environmental, and pavements/materials engineering. The reasons were to improve competitiveness for external research funding and expand the learning experience for the departments undergraduate students. At the time the departments structural engineering faculty included just three professors: Drs. Bonell, DeAngelis, and Douglas. But in 1979 Drs. Mehdi (Saiid) Saiidi and Gary Norris were hired. Dr. Saiidi was appointed from the University of Illinois at Urbana Champaign with expertise in the seismic performance of reinforced concrete structures, and Dr. Norris from the University of California, Berkeley with expertise in geotechnical engineering. With the addition of these two new faculty members, the earthquake program began to grow.

HISTORY

Fig. 1: Setting Up Pull Test Using a D-8 Tractor.


1984-1992Late in 1983, Dr. Douglas and Dr. Saiidi began planning the establishment of a research center in earthquake engineering to provide an organizational structure for faculty involved in earthquake research, enable the conduct of high quality research, and publish a technical report series. The result of this exercise was the Center for Civil Engineering Earthquake Research which obtained its first dedicated office space (SEM 111) and published its first technical report in January 1984. 1985 marked the Centers first cooperative international field test. At the time, NSF was interested in the work of the New Zealand engineering research community because it had a reputation for transforming research results to engineering practice quickly. The planning for collaborative research began in December of 1981 when a joint U.S./New Zealand Applied Technology Council workshop was held in Wairakei, New Zealand (NZ). The first cooperative project to be proposed was the large-amplitude, quick-release field testing of a set of bridges in New Zealand using the techniques develop at the University of Nevada, Reno. At Dr. Scalzis recommendation, NSF supported the U.S.-side with Dr. Douglas as PI. The NZ-side was supported by the National Roads Board, Central Laboratories, the head office of the Ministry of Works, and the Auckland City Council through the University of Auckland. The PIs for the NZ side were Dr. Ian Buckle (University of Auckland) and Dr. John Wood (Central Laboratories). Field experiments were conducted in January and February of 1985 on the Dominion Road Bridge (a curved, 10-span, 910 ft long, prestressed concrete box girder bridge in Auckland, NZ), shown in Fig. 2, and the Manga-te-waiti Bridge (a base isolated structure near Dannevirke, NZ). In addition to the above structures, ten other bridges in the U.S. were field tested during this period.

In April 1984, NSF funded a workshop at the University of Nevada, Reno to develop a set of research needs in earthquake engineering for bridges, and to identify the experimental facilities that would be required to satisfy these needs. The workshop was attended by many members of the national earthquake engineering community. The result was a strong recommendation for the construction of a National Bridge Engineering Laboratory located at a single site with substantial operating and research funding. The capital costs for the laboratory alone were projected at $100-$150 million. Accordingly, the University of Nevada, Reno and the State of Nevada proposed to NSF that this laboratory be located in Stead, NV, just north of Reno and be managed, operated and maintained by the Center under a grant from NSF. But the proposal was declined and the concept of a national bridge laboratory lapsed. This experience became one of the major factors in urging the University to move forward with the construction of an engineering laboratory building on campus. In 1987 the Nevada State Legislature appropriated $425,000 (Assembly Bill 64) for the design and planning of the new engineering laboratory, provided that $1 million was raised from the private sector. In response, the Nevada Section of the Associated General Contractors (AGC) helped the university to raise $1.8 million from local construction and engineering companies, and University of Nevada, Reno alumni. A 5,000 sq ft, high-bay bridge structures laboratory was planned for the building based on recommendations after visiting ten different university and government agencies that operated this kind of facility. Design of the building began in 1989 and was undertaken by Michael Blakely Structural Engineers. That same year the Nevada legislature authorized $9.8 million

for the construction of the building which is now known as the Harry Reid Engineering Laboratory. The building was completed in 1992.Personnel changes of note during this period include the retirement of Professor De Angelis in 1984, and the appointment of Drs. Emmanuel (Manos) Maragakis and Raj Siddharthan that same year. Dr. Maragakis came from the California Institute of Technology having completed his doctoral thesis in the area of earthquake structural dynamics of highway bridges. Dr. Siddharthan obtained his doctorate from the University of British Columbia and specialized in geotechnical engineering and soil dynamics. Dr. David Sanders joined the faculty in 1990 from the University of Texas at Austin with his primary expertise in the behavior of reinforced concrete structures.Fig. 2: Quick-Release Testing the Dominion Road Bridge in Auckland, New Zealand, 1985.


1993-1999The first project to be conducted on the strong floor of the new building was the ultimate load testing of a series of 700 ft long full-scale prestressed box girders recovered from the old Wells Avenue Viaduct in Reno. This project was funded by the National Science Foundation and it was conducted under the direction of Drs. Saiidi and Douglas. Shear, flexure, and fatigue performance of these girders was studied including their repair. The first doctoral graduate student to conduct research in the laboratory, Dr. Yolanda Labia, graduated shortly thereafter.The new laboratory provided the leverage necessary to pursue additional funding to further increase the Centers research capability and infrastructure. A successful proposal was submitted to NSFs Experimental Program to Stimulate Competitive Research (EPSCoR) and funding was received in two stages (1993, 1997) for a total of $1.26 million.Furthermore, as a direct result of the damage sustained during the 1989 Loma Prieta Earthquake in California, the Federal Emergency Management Agency (FEMA) awarded a total of $5.5 million to build a facility at the University of Nevada, Reno for simulating earthquakes using multiple shake tables. Following the advice of an External Advisory Committee, the decision was made to purchase two, 50-ton, uniaxial shake tables from MTS Corp. of Eden Prairie, MN. These custom-designed tables could be operated independently of each other, or simultaneously, with a total pay load of 100 tons (the largest in the U.S. at the time). In addition, a single 50-ton biaxial table could be assembled from the components of the two tables. The two shake tables were delivered in 1996 and commissioned in May of 1997. The first experiment to use one of the shake tables was conducted in 1998 with Dr. Sanders (PI), Dr. Douglas, and Dr. Saiidi. Funded by Caltrans, the project studied the performance of a reinforced concrete bridge column and required the development of an off-table mass rig to correctly model the inertia forces acting on the column (Fig. 3 and Fig. 4). The graduate student was Patrick Laplace. The mass rig is still in use today.Once the two shake tables were installed, it was apparent that the laboratory was too small. Up to this point in time, specimens had been fabricated inside the lab but the shortage of space required this activity to be moved outside. In 1996 BJG Architecture + Engineering designed an outdoor fabrication yard with a moveable storage building; construction was completed in 1997. Once the fabrication yard was complete, BJG then designed an expansion to the existing laboratory. The floor space was increased by 50 percent to 150 ft x 50 ft.

The concrete box test floor and the crane rails were extended southward 50 ft. The principal funding for this expansion came from Mr. James E. Rogers, the founder and owner of Sunbelt Communications Company. Construction began in 1997 and was completed in 1999, at which time the laboratory was renamed the James E. Rogers and Louis Wiener Jr. Large-Scale Structures Laboratory.Personnel actions in this period began with the hiring of Dr. Ahmad Itani in 1994. Dr. Itani obtained his doctorate from the University of Michigan in the area of seismic resistance of steel moment frames. In 1999 Dr. Douglas retired and Dr. Ian G. Buckle was hired as the Director of the Center. Dr. Buckles expertise is in seismic isolation and seismic performance of bridges.

HISTORY

Fig. 3: Column under Test on a Shake Table in the Large-Scale Structures Laboratory.

Fig. 4: Off-Table Mass Rig Attached to a Column on the Shake Table.


2000-2009Following a series of damaging earthquakes in California, Japan, and Taiwan in the 1990s, and recognition of the need to upgrade experimental facilities in U.S. universities, the National Science Foundation called for proposals to establish the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a network of world-class earthquake simulation sites, in 2000.In response to this solicitation, the Center successfully proposed to upgrade the two existing shake tables from uniaxial to biaxial motion and add a third identical biaxial table (Fig. 5). The total budget for this upgrade was approximately $7.2 million and comprised $4.6 million from NSF with cost sharing from the Department of Energy ($1.0 million) and the Department of Housing and Urban Development ($1.6 million). The Large-Scale Structures Laboratory commenced operations as one of 15 NEES Equipment Sites under a management, operations, and maintenance agreement with NSF in 2004. NEES was a network of 15 (now 14) large-scale experimental sites that featured advanced experimental tools such as shake tables, wave basins, geotechnical centrifuges, dynamic loading systems, and field-testing equipment for studying earthquake effects at or near full-scale. All were linked to a centralized data repository and earthquake simulation software by high-speed, broad-band, Internet2. The NEESgrid network (as it was known) allowed the earthquake engineering user community to interact in real time with any of the networked sites and access the data repository.In addition to the construction of the NEES Equipment Sites, NSF also established a research fund for the use of these facilities. Several faculty were successful at winning awards under this program, including two Small Group Awards (2004, 2005) related to improving the seismic performance of bridges and one Grand Challenge Award (2007) related to the performance of non-structural components in buildings. All of these awards were multi-year, multi-million dollar grants, involving multi-investigator collaboratories with leading academic institutions led by the University of Nevada, Reno. Many of these projects pushed the state-of-the-art in earthquake engineering simulation well beyond anything attempted before. The testing of a 130 ft long, 0.3-scale, four-span bridge (2006) required three shake tables and two abutments fitted with servo-controlled actuators. This was the first time this configuration had been used and the successful synchronous control of the tables and actuators won the Laboratory the 2007 NEES Award for Innovations in Actuator Control.

Using remaining funds from the NSF-NEES Construction Award, a grant from FHWA, and a contribution from the Office of the Vice President for Research, a fourth shake table was designed, constructed, and commissioned in 2009. This 20-ton table (later upgraded to 50 ton) had six degrees-of-freedom (3 translations, pitch, yaw and roll) and could be used synchronously with the other three tables or operated independently. It was expected that this table would broaden the laboratorys research activities to include, for example, the seismic qualification of non-structural components.But just as in the mid-nineties, after the commissioning of the first two tables, the Laboratory was once again too small. Plans were therefore developed in collaboration with BJG Architecture + Engineering for a 23,000 sq ft expansion which included a 10,000 sq ft strong floor, 6,000 sq ft of offices for graduate students and visiting scholars, and a 7,000 sq ft interactive auditorium for research collaboration activities. Estimated to cost $20-23 million, about $3 million had been received by the end of 2009 from the U.S. Department of Energy. Fundraising continued for the remainder. Personnel actions in this period included the hiring of Dr. Patrick Laplace as Research Assistant Professor and Structures Laboratory Manager in 2001, and Dr. Gokhan Pekcan as an Assistant Professor in 2003. Dr. Laplace completed his doctorate in the earthquake engineering program at the University of Nevada, Reno and Dr. Pekcan obtained his doctorate at the University at Buffalo in earthquake protective systems. As a consequence of the NEES MOM and FHWA Awards, a number of other appointments were made during this period. These included Dr. Sherif Elfass as Research Assistant Professor and NEES Site Operations Manager (2005); Rodney Porter as NEES IT Systems Administrator (2008) replacing Chad Feller (2006); Kelly Doyle as CCEER Program Coordinator (2008) replacing Rita Johnson (2007); Chad Lyttle (2006), Todd Lyttle (2008) and Paul Lucas (1999, 2009) as Development Technicians; and Robert Nelson as Research Scientist (2009).

Fig. 5: Installation of the Third Biaxial Shake Table, 2001.


2010-2014This five-year period was notable for two reasons. First, two very large-scale projects were undertaken in the structures laboratory, probably setting world records for scale and complexity in a university facility. Both of these projects (Seismic Performance of Horizontally Curved Highway Bridges and Simulation of the Seismic Performance of Nonstructural Systems) are discussed in the Research Accomplishments section. The second major accomplishment was the construction of a new Earthquake Engineering Laboratory adjacent to the Large-Scale Structures Laboratory, and the doubling in the size of the high-bay floor area.In early 2010, Phase 1 of the laboratory expansion began using the $3 million from Department of Energy (DOE). These funds were used to complete the site work for an expanded fabrication yard and about half of the strong floor of the new building. Demolition of four university-owned houses along Evans Ave. occurred in November 2010 and mass excavation of the site followed soon afterwards. The rifle range building was also demolished and relocated to a new site on Valley Rd. Retaining walls were installed on the east and south sides of the site and a 15,000 sq ft fabrication yard was cast. This was followed by 4,800 sq ft of strong floor (50% of the final size of the floor), and comprised a six-cell heavily reinforced, concrete box girder on grade, that was 60 ft long, 80 ft wide, and 13 ft deep. Construction of this Phase was completed in April 2011 (Fig. 6)and the floor was used throughout the summer of 2011 as an outdoor laboratory for several research projects.In October 2010, the National Institute of Standards and Technology (NIST) awarded a construction grant for the completion of the building. This award required the university to provide a 20% cost share from non-federal funds. The total estimated cost for completion of Phase 2 was $15.3 million, of which NIST provided $12.2 million and the University $3.1 million. The project was bid in January 2012 and construction began in April 2012. During this phase, the remaining half of the strong floor was constructed, and enclosed in a steel-framed high-bay laboratory with 50 ft of headroom. A 4-story office suite was constructed along the north side of the lab to provide space for a control room, instrumentation and tool rooms, technician offices (Floor 1), staff and visiting scholars (Floor 2), graduate student offices (Floor 3), and mechanical equipment (Floor 4). A 140-seat auditorium was added on the north side of the office block with a lobby and entrance from Evans Ave. It will be equipped as a state-of-the-art telepresence facility as funds permit.

The construction of the building was essentially complete by April 2013, and a temporary certificate of occupancy given so that Phase 3 could begin. This involved installing hydraulic hardlines in the basement and the relocation of the four shake tables from the Large-Scale Structures Laboratory to the new building. In order to accommodate ongoing research, hydraulics were not shut down to install the hardlines until August 2013. This complex exercise took eight months and was undertaken by Patrick Laplace and his staff with assistance from MTS and two specialty subcontractors. Three of the four the tables were back in service in the Earthquake Engineering Laboratory by March 2014, and the fourth table was moved in April 2014. The total cost of the new facility, including (a) site work, funded by DOE (Phase 1), (b) construction, funded by DOE under Phase 1 and NIST/UNR under Phase 2, (c) relocation of the shake tables, funded by NIST/UNR during Phase 3, and (d) other costs, funded by the University of Nevada, Reno in Phase 3 (such as furniture), was about $19 million. Three single shake table projects were completed in the new laboratory in April and May 2014, and assembly of the first three-table project began in June 2014 for testing in July. Personnel actions included the hiring of Dr. Keri Ryan as an Assistant Professor in 2010. Dr. Ryan obtained her doctorate at the University of California, Berkeley in earthquake protective systems. Her appointment partially offset the loss of Dr. Maragakis when he became Dean of the College of Engineering in 2009. In 2012, Dr. Ramin Motamed was appointed as Assistant Professor in Geotechnical Engineering. Dr. Motamed obtained his doctorate at the University of Tokyo on the behavior of pile groups during liquefaction. Rodney Porter took early retirement and was replaced by Rebecca Hayhurst in 2013. Robert Nelson resigned his position as Research Scientist to work in the industry in 2013.

HISTORY

Fig. 6: Earthquake Engineering Laboratory Construction after Completion of Phase 1.


Geotechnical LaboratoriesThe Geotechnical Laboratories consist of the Basic Soil Testing Laboratory (BSTL), the Advanced Soil Testing Laboratory (ASTL), and the Large-Scale Geotechnical Laboratory (LSGL). All facilities are directed and managed by Dr. Sherif Elfass and Dr. Ramin Motamed. The laboratories, which are used for undergraduate and graduate teaching and research, are equipped to study the material properties of soil as well as the interactions between soil and structural elements, including geosynthetics.

Basic Soil Testing LaboratoryThis 1,355 sq ft laboratory is equipped with testing equipment for evaluating engineering properties of soils, including index properties, compaction characteristics, consolidation and its rate.

Advanced Soil Testing LaboratoryThis 1,500 sq ft laboratory houses specialized research equipment for advanced testing such as direct shear, flexwall permeability, and computer-controlled stress path and cyclic triaxial tests. It also houses an 80 in x 25 in x 32 in tall acrylic tank that is used to study the effect of liquefiable soil on model structures.

Large-Scale Geotechnical LaboratoryThis 485 sq ft laboratory is used to conduct large-scale to full-scale experiments. It is equipped with two dynamic hydraulic rams, a hydraulic pump, and a high speed National Instrument data acquisition system and is serviced by 10,000 lb overhead crane. Three unique containers are available to conduct a wide variety of large-scale soil-structure-interaction experiments: Laminar Soil Box: The laminar soil box is shown in Fig. 7

and has dimensions of 10.3 ft x 10.3 ft x 6.2 ft. The walls consist of alternating sections of aluminum and rubber gaskets that are glued together over the height of the box, and they rest on a stiffened steel base plate. There are twelve tie rods that vertically compress the gaskets and seal the segment interfaces. The rubber gaskets make the box flexible under horizontal shear loads and deforms laterally when shaken. The segmented nature of the box allows the soil deposit to be built up from the bottom, promoting

uniform sample preparation. When completely loaded, the soil box has a maximum payload of about 120 kips. An inflatable air bag and stiffened top steel plate can be placed over the box so it may be completely sealed. In this configuration, an air pressure up to 29 psi can be applied to simulate overburden pressure on the soil retained within the box. The laminar soil box can be assembled on the ground for static testing or on one of the biaxial shake tables for dynamic experiments.

Cylindrical Soil Tank: The cylindrical soil tank (Fig. 8) is made of in steel plate and measures 8 ft in diameter and 9 ft tall. The tank consists of three equal segments to allow for uniform sample preparation and to provide flexibility in specimen height. An overburden pressure simulating 30 ft of soil can be applied to the specimen through four hydraulic rams attached to a top stiff plate structure.

Large Pullout Box: The large pullout box, which measures 10.5 ft x 3.5 ft x 3.5 ft, is designed to conduct ASTM compliant pullout tests on a wide variety of geosynthetic products, including geogrids with long aperture size. The box is equipped with an inflatable air bag and stiffened top steel plate to simulate different overburden pressures.

FACILITIES

Fig. 8: Cylindrical Soil Tank in the Large-Scale Geotechnical Laboratory with Drs. Siddharthan, Elfass, and Motamed.

Fig. 7: Laminar Soil Box on a Shake Table.


Structural Engineering LaboratoriesThe Structural Engineering Laboratories consist of the Large-Scale Structures Laboratory (LSSL) and the Earthquake Engineering Laboratory (EEL), which are shown in Fig. 9. Both facilities are directed by Dr. Ian Buckle and managed by Dr. Patrick Laplace. They are assisted by laboratory technicians Chad Lyttle and Todd Lyttle. Both labs are equipped with state-of-the-art servo-hydraulic systems for simulating dynamic loads. Each laboratory features a strong floor, reaction wall, two high-capacity bridge cranes, and an advanced hydraulic distribution system. Hydraulic Actuators: The facility has ten actuators that

are available for quasi-static or hybrid testing. The specifications of each actuator are shown in Table 1. The laboratory has an eight-channel MTS Flex Test IIM system, a four-channel MTS STS system, and two MTS 458 analog controllers.

Data Acquisition: The laboratory features 392 channels of high speed and 152 channels of low speed data acquisition. Each conditioner allows plug and play instruments to be connected using the IEEE 1451.4 standard. All of the instruments contain their calibration information on an onboard chip which is read by the data acquisition system.

Video and Computer Systems: Test data is stored on local servers with a two terabyte data capacity. This data includes video that is captured by any of the four Sony High Definition cameras and four digital video recorders. The laboratory is also equipped with six flexTPS telepresence cameras that enable real-time activities in the laboratory to be viewed at http://neestpm.ce.unr.edu/portal?section=local_video.

Fabrication and Staging Area: An 15,000 sq ft fabrication, staging, and storage area is adjacent to the building (Fig. 10). Two large concrete beds are used for specimen fabrication. Three forklifts are used to transport specimens, equipment parts, and tools between the fabrication area and the laboratory.

Large-Scale Structures Laboratory Main Test Floor: The main test floor is a heavily reinforced

concrete slab with 7,500 square feet of tie-down area. It features 2,000 tie-down holes that are spaced on a 2 ft x 2 ft grid. The slab was designed as a one-way slab supported by the north and south basement walls. The principal reinforcement includes top and bottom mats of #14 Gr. 60 bars spaced at 12 in on center in both directions. The monolithic slab-wall and wall-footing joints create a box girder that is 13 ft deep, 56 ft wide, and 150 ft long.

Reaction Wall: A 20 ft x 19 ft x 2 ft post-tensioned wall is

Fig. 9: Large-Scale Structures Laboratory (left) and Earthquake Engineering Laboratory (right).

FACILITIES

Table 1: Hydraulic Actuator Specifications. Qty Actuator Model Load Capacity Stroke (in) Servovalve (gpm) Rating

2 244.22 22k Compression; 22k Tension 20 90 Dynamic



1 244.51S 220k Compression; 220k Tension 30 90 Dynamic

1 243.8 450k Compression; 320k Tension 40 15 Static

1 243.9 600k Compression; 450k Tension 20 15 Static

1 243.100T 945k Compression; 700k Tension 48 15 x 2 Static

Fig. 10: Fabrication Area Adjacent to the Laboratories.


located on the east side of the laboratory. It is perforated with tie-down holes on a 2 ft x 2 ft grid and is used for static and cyclic load testing. It can be configured in conjunction with the modular reaction blocks to accommodate a variety of loading systems.

Bridge Cranes: Two overhead bridge cranes span the laboratory. Each crane has a 25-ton capacity main hook with a smaller 5-ton auxiliary hook. The cranes have a clear height of 29 ft and travel in the longitudinal and transverse directions. They are remotely controlled and can operate in unison or independently of each other.

Earthquake Engineering Laboratory Shake Tables: The laboratory is equipped with three biaxial

MTS shake tables and one six-degree-of-freedom (6DOF) shake table, shown in Fig. 11. All of the shake tables are relocatable on the laboratory floor and can be controlled to act together as a single large table or operate individually with independent motions. Each biaxial table measures 14 ft x 14.6 ft with a stroke of +/- 12 in and a peak velocity of 40 in/sec at 1g acceleration under a 50-ton payload. The 6DOF shake table measures 9.3 ft x 9.3 ft. The x, y, and z axes support strokes of +/- 12 in, +/- 12 in, and +/- 4 in and peak accelerations of 2g, 2g, and 3g respectively with a 50-ton payload.

Main Test Floor: The main test floor is a heavily reinforced concrete slab with 9,600 square feet of tie-down area. It features 2,200 tie-down holes that are spaced on a 2 ft x 2 ft grid. The slab was designed as a one-way slab supported by the east and west basement walls. The principal reinforcement includes top and bottom mats of #14 Gr. 60 bars spaced at 12 in on center in both directions. The monolithic slab-wall and wall-footing joints create a box girder that is 13 ft deep, 80 ft wide, and 120 ft long.

Reaction Wall: An L-shaped wall wraps around the southeast corner of the lab and can be used for independent experiments or in conjunction with the shake tables. It consists of an 80 ft x 20 ft x 4 ft wall along the east side and an additional 16 ft x 20 ft x 4 ft wall along the south side. It

is perforated with tie-down holes on the same 2 ft x 2 ft grid as the test floor. The wall is heavily reinforced with rebar tied into the strong floor for a monolithic connection.

Bridge Cranes: Two overhead bridge cranes span the laboratory. Each crane has a 30-ton capacity main hook with a smaller 5-ton auxiliary hook. The cranes have a clear height of 39 ft and travel in the longitudinal and transverse directions. They are remotely controlled and can operate in unison or independently of each other.

Office and Meeting Spaces: Dedicated rooms for control, instrumentation, and data analysis are located on the first floor of the building, north of the test floor. Staff offices are also located on this level. Additional offices for graduate students and visiting scholars line the north side of the high-bay laboratory on the second and third levels, overlooking the lab floor. Meeting spaces include a telepresence-equipped conference room on the second floor (Fig. 12) and an informal collaborative workspace on the third floor. There is also a 140-seat auditorium located inside the building that is equipped with a video wall and broadband Internet technologies.

Fig. 11: Four Shake Tables in the Earthquake Engineering Laboratory.

Fig. 12: Conference

Room Overlooking the

Lab Floor.

Table 3Table 2 Table 1

Table 4


ACCOMPLISHMENTS - RESEARCH

BridgesSince the installation of the third shake table in 2001, researchers have extensively studied the seismic response of bridge systems supported on multiple shake tables. These projects have been funded by major grants from NSF, Caltrans, NDOT, and FHWA, and include studies of structural seismic response under uniform ground motions, under fault rupture, with abutment pounding, and with advanced components, materials, and details. In addition, extensive analytical studies have provided greater insight into the behavior of bridges with various geometries, including skew and curvature. Listed below are some of the projects that have been undertaken to improve the performance of bridge structural systems.

Seismic Performance of 4-Span Bridge Systems with Conventional and Innovative DesignConventional standard bridges are designed to avoid collapse. However, these bridges suffer from severe damage under strong earthquakes, making them unusable and resulting in the shutdown of the highway network. The objective of the study was to conduct a comprehensive experimental and analytical investigation of the seismic performance of a series of large-scale, four-span bridge systems. This enabled researchers to understand the seismic performance of common bridge systems and to develop bridge columns that not only prevent collapse, but provide superior seismic performance so the bridge remains functional after a strong earthquake. The experimental part of the study included testing three, 4-span bridge models that were over 110 ft long. The test specimens consisted of (1) conventional reinforced concrete, (2) innovative materials such as Nickel-Titanium shape memory alloys (SMA) and rubber, and (3) fiber-reinforced polymer composite with accelerated bridge construction techniques. Fig. 13 shows the model with composite

piers. The study has led to several new discoveries, some of which were implemented in a three-span bridge in Seattle, Washington through a FHWA/WashDOT grant.

Seismic Performance of Horizontally Curved Highway BridgesThere are a growing number of bridges on sharply curved alignments throughout the U.S. and little is known about their seismic behavior. As a result, the Federal Highway Administration funded a series of shake table experiments to study the effect of curvature on the response of curved highway bridges. The structure tested was a 0.4-scale model of a three-span, steel girder bridge with a concrete deck. Spanning four shake tables, the model had a total length of 145 ft, a length-to-radius ratio of about 2.0, and a subtended angle of about 113 degrees. The model is shown in Fig. 14. Six configurations of the model were tested to examine the influence of different attributes, including column design (with and without conventional columns), abutment design (with and without backfill interaction), response modification devices (with and without seismic isolators), and the effects

of live load (with and without trucks on the superstructure). Between each test, the deck was disassembled and the damaged columns replaced. Data gathered from these experiments have been used to develop a set of seismic design guidelines for curved bridges, and fragility functions have been developed for use in loss estimation analyses of highway systems.Fig.13: Four-Span Bridge with Composite Piers.

Fig. 14: Curved Bridge with Trucks in Place.


Resilient Bridges of the Future Designed for DeconstructionExtreme loads such as earthquakes and hurricanes render structures dysfunctional and often destined for landfills. The global objective of this project was to develop novel precast concrete bridge elements that can resist extreme loads and yet remain functional with no or minor repair. Another objective of the study was to develop connections that allow for deconstruction and reuse of these columns. Through close collaboration with four advanced technology small businesses, advanced materials and details with demonstrated potential were adapted and novel connections were developed to allow for disassembly of bridge columns. A variety of novel materials such as glass-fiber reinforced composites (GFRP), copper based shape memory alloys, titanium based shape memory alloys, rubber, and engineered cementitious composites (ECC) were investigated. Figure 15 shows a concrete filled GFRP column shell being assembled onto an ECC element with titanium-based SMAs. Preliminary shake table tests were completed in May 2014 and system tests using a bridge model will be conducted in fall of 2014.

Stability of Bridge Rebar Cages during ConstructionRebar cages are the skeletons of reinforced concrete columns and are formed by connecting the longitudinal and transverse reinforcement with tie wire connections. The recent collapse of several bridge rebar cages (Fig. 16) showed the need to establish guidelines to enhance the lateral stability of these temporary structures. An experimental investigation was conducted on two full-scale rebar cages to determine their lateral stability and to calibrate nonlinear computational models. Using these calibrated models, the effects of various cage parameters on the lateral stability of rebar cages were investigated. Results from the investigation showed that the internal bracing provides a significant portion of the cages lateral stiffness and strength, and guidelines to improve the lateral stability of column rebar cages have been proposed.

Seismic Retrofit and Repair of Reinforced Concrete Bridge ColumnsStandard bridge columns may sustain major damage during earthquakes leading to closure of the bridge for repair. Ideally, engineers would like to limit disruption to service to a few days with a reliable and cost-effective repair strategy. This project aimed to devise methods to quickly restore earthquake-damaged bridge columns. Four standard concrete columns and two substandard concrete columns were tested on a shake table and damaged. The columns were then repaired and retested to evaluate the repair method. The repair process consisted of straightening the column, removing the loose concrete, injecting epoxy into the damaged area, repairing the concrete using a fast-set non-shrink mortar, applying carbon fiber reinforced polymer wraps (Fig. 17), and accelerating the cure time using a tent and heaters. Each column was repaired in one day. Test results and computer simulations indicated that repair of standard bridge columns should be designed using the new method developed in this study whereas substandard column repair may be designed using seismic retrofit guidelines.

Fig. 15: Assembling Bridge Column with ECC and Titanium-Based SMA.

Fig. 16: Collapse of Rebar Cage Test Specimen.

Fig. 17: Wrapping a Damaged Column with CFRP.



Bridges (cont)Pretensioned Bridge Columns for Rapid Construction and Earthquake ResilienceConventional bridges are slow to construct and often damaged during large seismic events. The objective of this project was to develop a bridge that may be quickly constructed and will experience limited damage during a large earthquake. A rocking, pretensioned bridge bent system was developed at the University of Washington, where individual column tests were conducted. Collaboration with researchers at the University of Nevada, Reno led to a system-level experiment in the Earthquake Engineering Laboratory. The model consisted of a two-span bridge configuration that had been used previously to investigate conventional bridge construction and details. The new system reduced construction time by precasting the beams and columns, and minimized post-earthquake damage and residual displacements by incorporating unbonded, pretensioned strands in the columns (Fig. 18). The bridge consisted of two-column bents of different heights, one on each of the three shake tables By using the same bridge configuration as the conventional bridge tested previously, direct comparisons could be made to determine the seismic resilience of the rapid construction system.

Columns under Complex LoadingIt is critical to have a basic understanding of how columns behave under extreme loading to determine how they should be analyzed and designed. In the past, almost all column experiments have been conducted with loading in one lateral direction with constant axial load. This goal of this project was to understand the behavior of bridge columns under actual loading conditions which will include bidirectional lateral load, variable axial load, and torsion. The project included cyclic experiments with lateral load and torsion, and hybrid experiments with variable axial load and torsion. The work conducted here included the development of a bidirectional mass rig, which loads single cantilever columns under biaxial excitations with a shake table (Fig. 19 and Fig. 20). The system is composed of a platform that rests on clusters of ball bearings placed on top of a three-dimensional frame. The platform is connected to the specimen through links that transfer torsion and shear, but not axial load. Additional mass is loaded on the platform to simulate the mass of a bridge superstructure during an earthquake. Axial load is applied through a vertical actuator and horizontal actuators adjust for P-delta effects. The results from these experiments have been used to validate analytical models, and develop new inelastic models from reinforced concrete columns under combined loading.

Fig. 19: Bidirectional Mass Rig on the Shake Table.

Fig.18: Schematic of Pretensioned Bridge Column.

Fig. 20: Column in the Center of the Bidirectional Mass Rig.


Behavior of San Francisco Oakland Bay Bridge ComponentsSeveral components for the San Francisco-Oakland Bay Bridge (SFOBB) were tested in the Large-Scale Structures Laboratory to determine the need for retrofit of existing spans and help engineers design the new eastern self-anchored suspension span. The following components were studied: Shear Links: Large-scale experiments were conducted on

the built-up shear links and their connections proposed for the towers of the new self-anchored span of the San Francisco Oakland Bay Bridge. The laboratory setup is shown in Fig. 21 and the final locations of the shear links are illustrated in Fig. 22. The objective of these experiments was to determine the deformation capacity, maximum resistance, and ultimate failure mode of a family of shear links, with and without web stiffeners and a variety of plate steels such as ASTM A709 Gr. 50, ASTM A709 HPS Gr. 70, Japanese LYP Gr. 14.5, and 30 ksi. The results illustrated the suitability of these types of steel for seismic applications, but the over-strength associated with each type varied significantly. The typical failure mode for a stiffened link was at the weld toe of the stiffener to the web, while the failure mode for the unstiffened web was the weld between the flange and the web.

Gusset Plate Connections: Large-scale experiments were conducted on double gusset plate connections that are found in the existing spans of the SFOBB to determine the behavior of the edge buckling of these plates. The results of these experiments showed that AASHTO edge buckling equation should be modified in order to capture the observed behavior.

Laced Members: Many SFOBB members are made of built-up shapes that are interconnected with lacing (Fig. 23). The axial and tensile capacities of these members depend on the interaction between the main components and the lacing elements. Large-scale experiments were conducted on laced members to establish their axial capacities and failure modes. The results of these experiments showed the AASHTO equations need to be modified to determine the axial capacity of laced members.

Perforated Members: The laced members of the SFOBB proved to have inadequate axial capacity under seismic loads. Based on this finding, the laced members were replaced by perforated plates (Fig. 24) in an effort to improve the ductility and the axial capacity. Large-scale experiments were conducted on the perforated members to determine their axial capacity and failure modes. Based on these experiments, it was shown the AASHTO equations can be used to accurately determine the axial capacity.

Fig. 21: Laboratory Testing of the SFOBB Shear Links.

Fig. 23: Laced Members in the SFOBB.

Fig. 22: Tower with Shear Links in the SFOBB.

Fig. 24: Perforated Members in the SFOBB.

Shear Link



BuildingsExperimental and analytical research has been conducted on various types of buildings to determine how to design more resilient structures. Much of this research is expected to be incorporated into building codes and implemented in the field, preserving life safety during extreme events. Some of these projects are described below.

Unbonded Post-Tensioned Rocking Walls for Seismic Resilient StructuresThe damage caused in buildings by earthquakes and the subsequent economic losses emphasize the need for seismically resilient structures. One method to do this is through the use of self-centering structural systems that are typically designed with lightly prestressed unbonded post-tensioning tendons. Researchers from Iowa State Univeristy developed a cost-effective solution known as PreWEC, which was formed by joining a Precast Wall with two End Columns using easily replaceable energy dissipating elements. With strong collaboration opportunities with E-Defense and NEES@Auckland, the project focused on the development of seismic resilient building solutions utilizing the fundamental characteristics of seismic rocking of both single walls (SRW) and PreWEC. In addition to developing new knowledge in the areas identified above, significant effort was placed on the identification of different energy dissipation sources of rocking walls such as impact (or radiation damping), viscous damping and hysteretic damping, and the influence of hysteretic damping on the impact energy loss. Four walls have been tested to date (Fig. 25), and the remaining two will be tested in the Earthquake Engineering Laboratory in the summer of 2014.

Evaluation of Innovative Isolation Systems in a Full-Scale Building Tested at E-Defense Base isolation is generally regarded as an effective method to achieve higher seismic performance objectives, but validation by full-scale testing or field observation following

strong shaking has been rather limited. To address this shortcoming, a series of experiments were conducted utilizing a full-scale 5-story, 2 bay x 2 bay steel moment frame building constructed on the E-Defense shake table in Miki, Japan (Fig. 26). The building was tested in three configurations: isolated with triple friction pendulum bearings, isolated with a hybrid system of lead-rubber and cross-linear bearings, and in the fixed-base configuration. The building incorporated a realistic floor system, and nonstructural components including partition walls, suspended ceiling, and sprinkler piping on the 4th and 5th floors. Two interior rooms were staged with hospital and office contents. The experiments were a collaboration between two NSF funded projects (NEES TIPS and the nonstructural systems grand challenge project described on page 17) both led by the University of Nevada, Reno and the National Research Institute for Earth Science and Disaster Prevention in Japan. The tests on the hybrid isolation system were funded by Nuclear Regulatory Commission. Besides the lead organizations, the project involved collaborators from UC Berkeley, University at Buffalo, San Jose State University, and Tokyo Tech, as well as industry collaborators and sponsors. The tests have been used to validate assumptions used in the analysis and design of base-isolated buildings. The tests led to several new findings about the role of vertical acceleration in the seismic performance of nonstructural components and contents.

Fig. 26: Steel Moment Frame Building Tested on E-Defense Shake Table, Miki, Japan.

Fig. 25: Rocking Wall on the Shake Table During Testing.


Seismic Performance of Innovative Straw Bale Wall SystemsModern building methods that are seismically resistant are largely unaffordable in developing countries such as Pakistan. One solution proposed by the Pakistan Straw Bale and Appropriate Building (PAKSBAB) organization is the use of earthquake-resistant straw bale building methods that are inexpensive, energy efficient, and utilize locally resourced renewable materials. In a project funded by the Endowment Fund of the Earthquake Engineering Research Institute, PAKSBAB joined with the University of Nevada, Reno to determine the performance of earth plastered, load bearing, thin, straw bale wall assemblies under in-plane cyclic loading, and the performance of a full-scale small straw bale house (Fig. 27) using shake table simulation. The site-fabricated bales were not as wide as those used in a typical straw bale building, and the earth plaster was reinforced with fishing net. This same net anchored the walls to the gravel bag foundations. The tests revealed that the straw bale house performed well under seismic loading, and PAKSBAB has trained about 60 people and built 27 houses in Pakistan since the completion of this project.

Gap Damper to Control Seismic Isolator Displacements in Extreme Earthquakes Engineers have questioned the reliability of base-isolation to protect structures if larger-than-expected shaking were to cause the displacement capacity of the isolation system to be exceeded. A new gap damper system was developed as an additional line of defense against this phenomenon. A three-story 0.25-scale building isolated with four lead-rubber

Fig. 27: Construction of a Full-Scale Straw Bale House for Testing in the Large-Scale Structures Laboratoy.

Figure 28: Three-Story Building Frame with Gap Damper System in Basement.

Fig. 29: Bumper Attached to Four Viscous Dampers.

bearings (Fig. 28) was tested with a gap damper on a biaxial shake table in the Earthquake Engineering Laboratory. A gap damper, consisting of four viscous dampers attached to a bumping system (Fig. 29), was placed underneath the structure. It was designed to limit excessive deformation of the isolation system without causing impact against a hard stop and the associated high frequency motions and accelerations. The study resulted in an experimentally and analytically validated framework for reliable, performance-based isolator design for buildings under different seismic scenarios. The work has led to improved designs of base isolation systems for vital facilities such as hospitals, emergency operation centers, fire stations, and other important buildings.



Non-Structural SystemsNonstructural components and systems in buildings are not part of the structural load-bearing system, but are subjected to the same dynamic environment experienced by a building in an earthquake. Damage to nonstructural systems occurs at ground motion intensities much lower than those required to produce structural damage. Recent earthquakes have demonstrated that poor performance of nonstructural systems and components can result in significant damage. Since these systems almost always represent a major portion of the total investment in a building, damage to non-structural components is very costly. The ceiling-piping-partition (CPP) nonstructural system is a very widely used nonstructural system that consists of piping, partitions, ceilings, and other similar components. All of these subsystems have suffered significant damage in recent earthquakes, which is a main contributor to both seismic damage and associated property damage. Such damage has resulted in property loss, loss of function, increased fire hazard and loss of life. Below are summaries of two major studies on subsystems and components of the CPP nonstructural system conducted in the Large-Scale Structures Laboratory.

Hospital Piping SubassembliesA series of drift experiments were conducted on welded and threaded hospital piping subassemblies to identify their characteristics with and without seismic bracing. Each specimen was made up of approximately 100 ft of 3 in and 4 in diameter, Schedule 40, ASTM A53 Grade A black steel pipe. They included two water heaters, one simulated heat exchanger, one y-strainer, one check valve, and two gate valves. The water heaters and the heat exchanger were anchored to a shake table and the pipes were braced and hung from a stationary frame, which rested on the lab floor. The test setup is shown in Fig. 30. The pipes were filled with room temperature water under normal hydrostatic pressure. Results showed that the braces limited the displacements, but they did not significantly reduce the accelerations of the subassembly. There was no significant damage

to the welded subassembly, and leaks began at a drift ratio of 5.0 percent. However, the threaded piping subassembly suffered minor leaks at a drift ratio of 2.2 percent and experienced failure level damage at a drift ratio of 4.3 percent. Similar experiments were conducted using copper piping subassemblies.

Simulation of the Seismic Performance of Nonstructural SystemsThe purpose of this project was to develop a simulation capability and implementation process for enhancing the seismic performance of the CPP nonstructural system. This project was funded by NSF to perform integrated multidisciplinary system-level studies. Since 2007, a comprehensive experimental program has been underway at the University of Nevada, Reno in a collaboration with the University at Buffalo. A series of system-level, large-scale experiments were conducted in the Large-Scale Structures Laboratory from December 2012 to April 2013. These experiments focused on the investigation of the system-

level responses of CPP nonstructural systems by using a two-story test bed structure mounted on three shake tables (Fig. 31). During these experiments, several failure models in the CPP nonstructural systems were identified, which will help the community implement nonstructural mitigation programs.

Fig. 31: Two-Story Braced Steel Frame Test Bed Spanning Three Shake Tables.

Fig. 30: Hospital Piping Frame on a Shake Table.


Service-to-IndustryRecent changes in design codes and regulations (such as the 2006 International Building Code) require seismic qualification of mechanical and electrical equipment and their mounting systems before installation in hospitals and other critical or essential facilities. Over the past fifteen years there has been an increasing demand for seismic certification and response assessment of nonstructural systems and components. Seismic qualification via shake table testing has become a standard requirement for these systems in industry. The Earthquake Engineering Laboratory has the equipment to perform this qualification work and is able, for example, to meet requirements of AC156, GR-63-CORE, and IEEE 344/693. Over 50 seismic qualification tests of various nonstructural components and systems have been completed successfully since 2000 and CCEER has published over 30 reports with a special report series Civil Engineering and Nonstructural Testing. These tests include wall-mounted TV monitor arms, mobile shelving units, radiography and fluoroscopy systems and components (e.g. patient tables, control units, ceiling-mount tube suspensions), CT scanners, gantry, surgical lighting, main frame servers, monitoring panels, battery boxes, antenna extrusions, generators, chillers, and air handling units. In addition, various mitigation strategies such as isolated floor implementations for nonstructural systems have been experimentally evaluated using the shake tables. To expand its service-to-industry program, the Center has also paired with Dynamic Certification Laboratories, LLC (DCL). DCL is a testing facility located in Sparks, NV that specializes in seismic qualification of critical equipment. The company uses the 6DOF shake table in the Earthquake Engineering Laboratory when test specimens exceed the size or payload capacity of their own shake table. Some recent projects conducted by DCL at the University of Nevada, Reno are described below.

IEEE 693 Seismic Qualification by Shake Table TestingHigh voltage power substations are a crucial element to the nations electrical power grid. These power substations are essential to the continued operation of critical facilities such as hospitals, fire stations, and disaster operation centers. During a large seismic event these facilities are vulnerable to equipment damage which could lead to shut down of the power system. Shake table testing was conducted on a composite surge arrestor (Fig. 32) which are used in high seismic areas. The equipment was tested to the High Performance level of the IEEE 693 Recommended Practices for Seismic Design of Substations. The goal of the testing was

to certify that the equipment could reliably survive the seismic event and continue to serve its intended function. By validating equipment performance through shake table testing, power substations can continue to operate even after a major seismic event.

ICC-ES AC156 Shake Table Testing of Nonstructural ComponentsCooling towers are considered nonstructural components in buildings and must be operational after large sesmic events. To ensure these units meet building code requirements, a large cooling tower was tested on the 6DOF shake table (Fig. 33). Towers like these are installed in hospitals across California to provide chilled water for the buildings HVAC systems, X-ray machines, and other medical devices. The unit was tested to the highest expected seismic event in California based on ASCE 7-10 guidelines. The goal of the testing was to validate that the cooling tower would still serve its intended function after a major earthquake.

Fig. 32: Composite Surge Arrestor on the 6DOF Shake Table.

Fig. 33: Cooling Tower on the 6DOF Shake Table.



Geotechnical EngineeringResearchers in Geotechnical Engineering have investigated the behavior of different soils and their interaction with piles, foundations, and walls during earthquakes. Analytical and experimental studies help engineers better predict soil behavior and design components to resist soil loads. Below is a summary of some of the geotechnical research conducted at CCEER.

Laterally-Loaded Pile ResearchResearch has been undertaken to develop a laterally-loaded pile computer program for bridge pile foundation analysis and design. The analysis method and supporting program is named the Strain Wedge Model (SWM). The basic concept is that a passive wedge of soil provides the lateral resistance to a pile or drilled shaft that is loaded at its head with a lateral force and/or moment. The analysis provides the so-called p-y curves of the soil with increasing depth. These curves are derived from triaxial stress-strain tests of the soil. The analysis method effectively relates a three-dimensional soil response to the desired one-dimensional p-y curve spring that was previously obtained only from back calculations of field data (from which considerable extrapolation was needed). The SWM analysis takes several variables into account, and the following are improvements over traditional p-y curve analysis: Layered Soil Conditions - The model recognizes layered

soil conditions and the effect or presence of one soil layer on the response of another (i.e. soil continuity).

Cross-Sectional Shape - The method considers the influence of the cross-sectional shape of the pile, its flexural rigidity and the head condition (fixed or free).

Vertical Side Shear Resistance - The analysis accounts for the additional resistance of vertical side shear as the pile or shaft deflects laterally and rotates from the vertical. This is important for drilled shafts with large diameters because they can develop considerable side shear resistance to deflection and rotation.

End Effects - The analysis also treats end-effects (bottom shear and bottom moment) of short and intermediate length shafts that traditional p-y curve programs do not consider (traditional analysis assumes piles and shafts are infinite in length).

Nonlinearity - The program looks at the nonlinear nature of the pile or shaft, changing the pile or shafts flexural stiffness (EI) as a function of the moment at increasing depth.

Pile Groups - The SWM method can analyze piles or shafts in groups with a given spacing. Neighboring piles develop overlap of wedges with depth and applied load (Fig. 34). Therefore, each pile has a unique response, depending upon its location within the group. This approach is valuable because the traditional p-y method applies factors to each individual pile p-y curve (which are constant with depth and load). These factors are taken as a function of the row where the pile is located, and have been determined from a very few field tests with little consideration of the other variables (i.e. soil layering and pile properties) that might affect group interference.

Liquefaction - Since SWM analysis is based on tested soil stress-strain behavior, the undrained response of sands that experience liquefaction can be accurately analyzed with characterized stress-strain behavior of the soil. Conversely, the traditional p-y approach produces a curve with an incorrect shape for completely liquefied soil, and empirical corrections are suggested for that analysis method.

Fig. 34: Overlap of Wedges in a Pile Group.


The application of the Load and Resistance Factor Design (LRFD) approach in foundation design has drastically increased in recent years and is now required for all bridges funded by the Federal Highway Administration (FHWA). In addition to bridge foundations, LRFD is increasingly used to design the deep foundations for tall buildings. One challenge associated with this, however, is the determination of resistance factors which appropriately represent the regional soil conditions. The main objective of this research is to develop locally calibrated resistance factors for the design of drilled shafts in Las Vegas based on LRFD methodology. To do this, full-scale load test data on drilled shafts are being collected and compiled (Fig. 35). In addition, available soil profile information at the test sites is being gathered. A comprehensive reliability-based calibration will be carried out to properly develop resistance factors for axially loaded drilled shafts in Las Vegas, where deep foundations are commonly used as the foundation system for elevated highways and bridges as well as high-rise commercial and residential buildings. It is anticipated the outcome of this research will result in significant savings in the foundation construction of projects.

Laboratory Study to Assess Increase in Load Capacity of Drilled Shafts through Post GroutingSince it takes a great deal of movement for a drilled shaft to develop end-bearing in supporting soil, many engineers ignore end-bearing and design drilled shafts only with side shear resistance. A model of a drilled shaft segment was therefore tested in the laboratory to determine whether or not end-bearing should be a significant design parameter for these components. Several specimens were tested with and without post-grouting of the shaft tip. Post-grouting the tip of a drilled shaft is analogous to loading a shaft and eliminating a considerable amount of the plastic deformation of the supporting soil. Thus, upon reloading of the post-grouted shaft, only elastic deformation is required of the soil. Consequently, a significant load can be achieved from end resistance with deformation or movement similar to that

required for skin or shaft support. This Caltrans-sponsored research consisted of testing nine, 12-in diameter shafts in the Cylindrical Soil Tank. The test setup is shown in Fig. 36. The tank was filled with sand and had a cover plate that was tightened down with rods to simulate the effect of overburden to an equivalent depth of 35 ft at the level of the tip. Preliminary results indicated a seven-fold increase in tip resistance over the value allowed in current design for a tip movement of 5 percent of the diameter of the shaft.

Calibration of Resistance Factors for LRFD of Axially Loaded Drilled Shafts in Las Vegas Valley

Fig. 35: Drilled Shaft Construction for Southeast Connector Project in Reno-Sparks.

Fig. 36: Post-Grouted Pile Setup.


Civil and Environmental Engineering Summer CampEach year, CCEER pairs with the College of Engineering to host a five-day summer camp for students ages 14-18. This camp introduces students to major topics within Civil and Environmental Engineering, including lessons about communication, seismic design, water treatment, soil liquefaction, and bridge building. The camp features lectures by engineering faculty, hands-on experiments, and field trips to local construction projects. For example, students remove dye from water, build KNex bridges (Fig. 37) and load test them, construct reinforced soil columns, and design a tower using gumdrops and toothpicks that will withstand an earthquake on a mini shaking table. The camp concludes with student presentations to parents, faculty, and staff about the activities during the week. To find out more about the summer camps, visit www.unr.edu/engineering/research-and-outreach/k-12-outreach.

ACCOMPLISHMENTS - EDUCATION & OUTREACH

Graduate ProgramThe University of Nevada, Reno has excellent opportunities for graduate research in Civil and Environmental Engineering. The department offers both Masters of Science (M.S.) and Doctorate of Philosophy (Ph. D.) degrees in four main areas: Earthquake and Structural, Geotechnical, Pavements and Materials, Transportation, and Environmental Engineering. Students interested in the Earthquake and Geotechnical tracks have the opportunity to conduct research in the Structural Engineering and Geotechnical Laboratories. To find out more information about applying to the program, visit www.unr.edu/engineering.Graduate courses in Structural and Geotechnical Engineering are listed in Table 2 (note that not every course is offered every year). In addition, students may take graduate-level courses from other departments, such as Mechanical Engineering and Geological Sciences and Engineering, with consent from their advisor.

Graduate students have the opportunity to join many student groups and participate in seminars, attend software training classes, and take field trips to local construction sites. The College has student chapters for the American Society of Civil Engineers, the Earthquake Engineering Research Institute, Engineers without Borders, and the Society of Women Engineers. Participating in these organizations allows students to network with peers and enhance their graduate school experience.

Fig. 37: Summer Camp Students with Their KNex Bridge.

CEE 642 Fundamentals of Geotechnical Engineering CEE 724 Applied Elasticity ICEE 643 Geotechnical Engineering: Foundations CEE 725 Advanced Topics in Structural AnalysisCEE 645 Geotechnical Engineering: Retaining Structures CEE 726 Theory of Plates and ShellsCEE 646 Geosynthetics CEE 727 Matrix Methods in Structural AnalysisCEE 679 Earthquake Engineering CEE 728 Bridge Engineering IICEE 682 Design of Timber Structures CEE 729 Seismic Isolation of Structural SystemsCEE 683 Prestressed Concrete Design CEE 730 Dynamics of StructuresCEE 684 Bridge Engineering I CEE 731 Advanced Dynamics of StructuresCEE 686 Structural Analysis II CEE 741 Geotechnical Engineering: Seepage, Slopes, EmbankmentsCEE 687 Reinforced Concrete Design II CEE 742 Advanced Soil MechanicsCEE 688 Advanced Structural Steel Design CEE 745 Geotechnical Earthquake EngineeringCEE 704 Applied Finite Element Analysis CEE 746 Advanced Foundation EngineeringCEE 721 Non-Linear Structural Analysis CEE 748 Advanced Geotechnical LaboratoryCEE 722 Limit Design in Structural Steel and Concrete CEE 750 Graduate SeminarCEE 723 Advanced Reinforced Concrete CEE 771 Special Engineering Problems

Table 2: Graduate Courses in Structural and Geotechnical Engineering.


K-12 Seismic Design CompetitionIn 2012, a K-12 Seismic Design Competition was developed using NEES funding. The competition varies by age group and challenges students to construct earthquake resistant buildings out of gumdrops and toothpicks (Fig. 38) or balsa wood. The structures are tested on a mini shaking table to determine whether or not each building is earthquake resistant. CCEER has paired with the Terry Lee Wells Nevada Discovery Museum, Washoe County School District, ACE High School, and the College of Engineering to introduce hundreds of students to earthquake engineering. The challenge can take as little as 2.5 hours (for gumdrop structures) or as long as one week of class time (for balsa wood structures). Activity assessments show that 92% of students would like to participate in more activities like this, and that this particular design challenge makes more than 52% of students want to be engineers when they get older. Activity information, lesson plans, and assessment sheets can be found at nees.org/resources/5002.

Research Experience for UndergraduatesThe University of Nevada, Reno has been a host site for the NEES Research Experiences for Undergraduates (REU) Program since 2007. Each summer, between two and five undergraduate students come to Nevada for ten weeks and conduct research in earthquake engineering. Students work on graduate level research under the supervision of a faculty advisor and a graduate student mentor. Throughout the summer, they network with students, faculty, and professionals and present their research findings to REU students and faculty from other research sites at a Young Researchers Symposium. The Office of Undergraduate Research offers these students essential classes such as workshops on graduate school application, poster presentation techniques, and ethics in research. In addition, the students participate in weekly webcast meetings with REU students at other NEES sites to form a cohort. They also attend the NEES Annual Meeting, go on tours with the local chapters of ASCE and EERI, and visit other NEES sites during field trips with the REU Coordinator (Fig. 39).

Make Your Own EarthquakeThe Make Your Own Earthquake (MYOE) activity is used by the NEES@Nevada site to supplement laboratory tours and excite students about earthquake engineering. In addition, NEES installed an exhibit at the Terry Lee Wells Nevada Discovery Museum in Reno, NV, to physically engage students and teach them about earthquakes, how they are recorded, and how they are recreated in a laboratory. The activity allows students to jump on a surface instrumented with an accelerometer for ten seconds. The accelerometer reads their jumping activity and outputs it to a screen in real time. The final earthquake may be printed out and taken home by the student. Over 90,000 individual jumps have been recorded at the museum exhibit since its installation in October 2012. In addition, roughly 3,000 students have used the MYOE activity in the NEES@Nevada laboratory since 2011.

Fig. 39: REU Students Attending a Tour of the Golden Gate Bridge in San Francisco, CA.

Fig. 38: Students Building Structures Using Gumdrops and Toothpicks.


GRANTS AND CONTRACTS

AMERICAN IRON AND STEEL INSTITUTE2008 Development of LRFD Code Language for the Seismic Analysis and Design of Steel Plate Girder Bridges $20,000

CALIFORNIA DEPARTMENT OF TRANSPORTATION2004 Seismic Response of Flared Columns with Vertical and Horizontal Gaps $59,9392004 Bridge Seismic Analysis Procedure to Address Near-Fault Effects $372,955

2005 Seismic Response, Assessment, & Development of Recommended Design & Analysis Guidelines For Skewed Post-Tensioned Concrete Box Girder Highway Bridges $345,076

2005 Development of Improved Column Pin Connection Details and Design Procedures $265,386

2005 Develop and Assess Post-Grouting Methods to Increase the Load Capacity of Deep Foundations $268,509

2006 Guidelines for Seismic Design of Steel Girder Bridge Superstructures $359,532

2006 Testing of Pile Extension Connections to Slab Bridges $315,742

2006 Emergency Repair of Damaged Bridge Columns Using Fiber Reinforced Polymer (FRP) Materials $251,070

2007 Precast Bridge Columns with Energy Dissipating Joints $300,000

2008 Stability of Rebar Cages in Bridge Columns $240,000

2009 Effect of Live Load on Seismic Response of Bridges $310,875

2010 Seismic Performance of Next Generation Bridge (NGB) Components for Accelerated Bridge Construction (ABC) $307,815

2010 Post-Earthquake Bridge Damage Mitigation $151,952

2011 Repair of Earthquake-Damaged Bridge Columns with Fractured Bars $184,706

2011 Seismic Performance of Precast Bridge Columns with Grouted Couplers $100,000

2011 Calibration of Probabilistic Damage Control Approach (PDCA) for Seismic Design of Bridges $142,316

2011 Seismic Design of Column-Footing Connections with Pipe-Pin Hinges for Accelerated Bridge Construction $187,883

2012 Performance of the Column-to-Shaft Pin Connections in Type-II Shafts $279,539

2012 Nonlinear Lateral Performance of Skew Abutments $589,963

2014 Seismic Performance of Bridge Superstructures in Accelerated Bridge Construction $264,575

CARRIER CORP.2009 Seismic Qualification Testing of Cooling Systems $40,254

CATERPILLAR / HOLT OF CA2009 Shake Table Testing of Caterpillar Generators $28,026

DA-LITE SCREEN / ADVANCE PRODUCTS DIVISION2004 Shake Table Experiments (AC156) of Da-Lite Assemblies $19,215

EASE, INC., LOS ANGELES, CA2005 Shake Table Qualification Testing of Non-structural Systems $42,917

2009 Seismic Response Characterization of Nonstructural Systems for Critical Facilities $72,855

FEDERAL HIGHWAY ADMINISTRATION2007 Seismic Response of Near-Fault Bridges $422,386

2007 Improving the Seismic Resilience of the Federal-Aid Highway System Federal Highway Administration (Phase I) $3,652,614

2008 Seismic Response of Near-Fault Bridges $110,700

2008 Seismic Behavior of Steel Bridges with Integral Abutments $65,000

2010 Field Tests of Post-Grouted Drilled Shafts (with Caltrans) $260,000

Listed below is a sample of the research grants and contracts acquired by the faculty and staff of the Center for Civil Engineering Earthquake Research. This list includes contracts exceeding $10,000 over the past ten years. They are listed by sponsor name and year.

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2010 Seismic Response of Near-Fault Bridges $116,192

2012 Improving the Seismic Resilience of the Federal-Aid Highway System Federal Highway Administration (Phase II) $1,994,528

2013 A Self-Sensing Adaptive Material for New Generation of Multifunc

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