The Pocket Consultant Spring 2013

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The queson is simple enough: Where soil borings indicate the presence of high-quality, granular subgrade soils, can roads or other structures be built on them with lile or no improvements? The answer is also simple – yes. But historically, it has been too difficult to defend. Unl recently, there hasn’t been a sufficiently-comprehensive and reliable means of evaluang in-place material competency and compliance with project material and performance specificaons on a broad enough scale to avoid tradional excavaon and recompacon or replacement procedures. Now, technology has evolved to that point, and the recently completed Trunk Highway (TH) 610 project in Maple Grove, Minn., showed with some support from tradional tools, we now have a way to perform and rely on in-place subgrade evaluaons. The benefits and applicaon of the findings from this project to other types of projects have also been surprisingly abundant. The TH 610 project was designed and built under the Minnesota Department of Transportaon’s design-build program. The project was unique in that the highway was built on a new alignment subject to lile to no previous grading. Some of the soil borings provided by MnDOT indicated the presence of high-quality, natural sand at proposed subgrade elevaons; however, the baseline design provided by MnDOT required a 4-foot subcut across the enre project length. As part of MnDOT’s design-build process, contractor teams are allowed to propose Alternave Technical Concepts (ATC) to improve the project and/or save money. Braun Intertec with C.S. McCrossan and SRF Consulng Group Inc., recommended leaving the high-quality sands in place, and evaluang subgrade competency and consistency using a technology called intelligent compacon. This technology allows for construcon of pavements directly on sands without unwarranted subgrade correcons. braunintertec.com 1 VOL 16, ISSUE 1 SPRING 2013 PRACTICAL AND ENTERTAINING SINCE 1997 New Action in Intelligent Compaction Alternative method is a profound departure from traditional excavation and replacement continued on next page … By Matt Oman, PE [email protected]

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Braun Intertec: The Pocket Consultant Spring 2013

Transcript of The Pocket Consultant Spring 2013

Page 1: The Pocket Consultant Spring 2013

The question is simple enough: Where soil borings indicate the presence of high-quality, granular subgrade soils, can roads or other structures be built on them with little or no improvements? The answer is also simple – yes. But historically, it has been too difficult to defend.

Until recently, there hasn’t been a sufficiently-comprehensive and reliable means of evaluating in-place material competency and compliance with project material and performance specifications on a broad enough scale to avoid traditional excavation and recompaction or replacement procedures. Now, technology has evolved to that point, and the recently completed Trunk Highway (TH) 610 project in Maple Grove, Minn., showed with some support from traditional tools, we now have a way to perform and rely on in-place subgrade evaluations. The benefits and application of the findings from this project to other types of projects have also been surprisingly abundant.

The TH 610 project was designed and built under the Minnesota Department of Transportation’s design-build program. The project was unique in that the highway was built on a new alignment subject to little to no previous grading. Some of the soil borings provided by MnDOT indicated the presence of high-quality, natural sand at proposed subgrade elevations; however, the baseline design provided by MnDOT required a 4-foot subcut across the entire project length.

As part of MnDOT’s design-build process, contractor teams are allowed to propose Alternative Technical Concepts (ATC) to improve the project and/or save money. Braun Intertec with C.S. McCrossan and SRF Consulting Group Inc., recommended leaving the high-quality sands in place, and evaluating subgrade competency and consistency using a technology called intelligent compaction. This technology allows for construction of pavements directly on sands without unwarranted subgrade corrections.

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V O L 1 6 , I S S U E 1 S P R I N G 2 0 1 3P R A C T I C A L A N D E N T E R T A I N I N G S I N C E 1 9 9 7

New Action in Intelligent Compaction Alternative method is a profound departure from traditional excavation and replacement

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By Matt Oman, PE [email protected]

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Practical and Entertaining Since 19972

Intelligent compaction from the ground upAccording to MnDOT Research Services Section, Intelligent Compaction (IC), also referred to as continuous compaction control (CCC), originated in Europe in the 1970s and was first used in Minnesota in 2004 on a demonstration project. MnDOT continued using IC on pilot projects and has recently started using IC for general embankment and aggregate base construction.

The Caterpillar roller instrumented with Trimble equipment used on the TH 610 project relied on drum-mounted accelerometers to continuously measure the reaction between the roller drum and ground surface. Mathematical algorithms process the extensive amounts of data and calculate an index parameter referred to as the compaction measurement value (CMV).

The CMV is related to soil properties, including moisture content, density, strength, and stiffness, and roller properties, including drum diameter, weight, frequency, amplitude, and speed. Through the generation of CMV values, IC technology not only helps delineate the extent of soft and stiff subgrade soils, but can also reveal the location and influence of inclusions like utilities.

A bold solutionThe traditional application of IC technology is to evaluate material compaction by creating a “map” of CMV values as subgrade fill is placed and compacted. Given what the team knew about the high-quality, natural sands along a portion of the TH 610 alignment, Braun Intertec proposed to perform IC mapping before construction to determine if and where excavation and recompaction or replacement of the in-place soils could be avoided altogether. This proactive type of subgrade qualification, including the application and analysis of CMV data on in-place soils, had never been tried before and ultimately redefined pavement subgrade evaluation and construction in a way not previously considered.

The IC approach used on the TH 610 project generally adhered to the project requirements, though MnDOT’s Special Provisions and Quality Manual sections were modified to include reference to in-place (in addition to placed and compacted) soils, and moisture content requirements were waived (moisture conditions at depth within unexcavated soils being beyond the contractor’s control). The team still adhered to soil density requirements (compaction to 100 percent of standard Proctor density in the top 3 feet and 95 percent compaction below) and test rolling (deformation testing with a trailer with two tires loaded to approximately 30,000 pounds each).

The team evaluated control strips to begin the process and qualify the data when changes in soil type or moisture content evidenced by the CMV data dictated the need. Along each control strip, four test holes were excavated to allow visual characterization of the subgrade soils and testing in accordance with the project’s Quality Control (QC) density requirements. After final IC mapping, the team subjected control strips to Quality Assurance (QA) test rolling.

Test holes were located where the fifth highest and 95th percentile CMV values and the fifth lowest and 5th percentile CMV values were generated. If the soils observed and tested at these locations met material requirements, the lowest CMV value

The schematic illustrates the ability of IC technology to detect subsurface anomalies, such as uncharacteristically soft or stiff soils.

… Intelligent Compaction continued

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corresponding to passing QC and QA tests was identified as the target value for further IC operations. Armed with the target value, the roller operator surface-compacted the alignment until they generated CMV values equal to or higher than the target value. At that point, the final “proofing” was performed on the surface and reviewed by the contractor’s construction quality manager.

At the discretion of MnDOT, the team verified any CMV outliers (high or low) with hand auger borings and moisture content testing. A deviation of more than 2 percent below or above the average moisture content represented by the control strip soils required a supplemental control strip and target value.

Data overloadRudimentary cleansing of the data was necessary prior to analysis in order to evaluate quality data and avoid misleading conclusions. Examples of data eliminated prior to analysis included data collected in reverse, not applicable values for CMV, roller speed, and GPS coordinates, and roller speeds less than 1 mph and greater than 4 mph.

Although IC data is very useful, most of the raw data is not easy to share, explain or analyze. Quick turnaround of the results was necessary, so Braun Intertec developed a spreadsheet solution to process, evaluate, and present the IC data to the contractor and MnDOT staff in the field. The most complex task was incorporating a spatial component to the data, which we solved by creating “bubble plots.” Data points were plotted by GPS coordinates on the x- and y-axis, and the bubble size was varied with CMV values. Small bubbles indicated low CMV values and soft or weak subgrade soils; such areas typically failed test rolls later in the process.

Braun Intertec’s IC application and data analysis method helped validate IC technology and its use on in-place soils. The application addressed the following three variables crucial to process qualification and complete buy-in from MnDOT:

Statistical consistency: We evaluated an area of the subgrade built using traditional layered construction and quality control, and mapped the surface with the IC roller. We compared these results to a nearby area not constructed in layers but underlain with natural soils. The statistical signature between the two areas was almost identical

when comparing the 5th percentile, 95th percentile, and average CMV values.

Soft spot detection: To investigate the capability to locate soft spots, we mapped the surface of a traditionally built area and subjected it to test rolling. After analysis of the IC data, we were able to predict with a high degree of accuracy where test rolling would fail based on the relative CMV values.

Poor soil detection: During proof-of-concept testing, we encountered an area with unusually low CMV values. Through test pits and observation, we discovered large pockets of silt, which produced the low CMV values.

Based on the relatively small data set of moisture contents and soil types, it appeared that CMV increases with Proctor maximum dry density and decreases with an increase in moisture content.

Oh the possibilities …By using IC data to evaluate the in-place soils on the TH 610 project, Braun Intertec pioneered a more efficient way to demonstrate and document the construction quality of roadway subgrades and subbases underlain with high-quality, natural sands. The method provides 100 percent coverage, and the evaluation minimizes the risk of not detecting and improving poorly compacted soils, thereby reducing future maintenance and reconstruction costs due to settlement or poor performance. continued on next page …

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The manual evaluation of control strips following IC provided evidence that vibratory compactors can affect soil densification to a depth of 4 feet or more in sands. This IC application and data analysis method can change the way the construction industry specifies and constructs granular subgrades and subbases for pavements and other structures. Structures possibly benefiting from IC technology include building pads, spread and mat type foundations, and excavations associated with general site development or mining.

On the TH 610 project, we performed this IC approach between Revere Lane and Jefferson Highway. By eliminating the planned 4-foot subcut in this area, C.S. McCrossan was able to reduce its excavation quantity by approximately 18,000 cubic yards. At the same time, it reduced the placement of an equal amount of granular and select granular borrow material.

The IC process also proved a green alternative to conventional subgrade preparation processes. Overall compaction efforts were reduced by up to 80 percent, which limited diesel fuel consumption by approximately 3,000 gallons and lowered carbon dioxide emissions by approximately 300 tons.

Despite investing money and time into IC equipment and training, C.S. McCrossan was able to reduce project costs by about $370,000, and because this was part of the proposal and ATC process, these savings were passed on to Minnesota taxpayers.

This more efficient construction process can reduce the overall costs associated with roadway construction if the soil conditions allow. When applied, this method shortens the construction schedule, minimizes high-cost/high-demand materials, and limits labor required for testing and construction oversight. By shortening the project schedule, this method greatly reduces impacts to the community, including reductions in traffic disturbance, vibration, noise, dust and stormwater runoff. If used correctly, this innovative construction method could save Minnesota taxpayers millions of dollars while increasing pavement life. ■

Intelligent compaction incorporates vibratory rollers with GPS devices and accelerometers to continuously measure the reaction between the roller drum and the ground surface.

Braun Intertec Helps Launch Mission to Mars

One of Braun Intertec’s newest ventures is extraterrestrial – Mars InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport). This NASA Discovery Program is managed by NASA’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology in Pasadena, Calif., with involvement from scientists and engineers from around the world. NASA is gearing up to perform geophysical investigations of the planet Mars, one of which will determine planetary heat flux, using the Heat Flow and Physical Properties Package (HP3) instrument that penetrates into the subsurface and performs temperature and thermal conductivity characterizations. To assess the instrument system’s penetration capabilities, we will be testing a variety of simulated Martian soils with similar properties to those expected at the landing site on Mars.

Braun Intertec’s materials laboratory will help NASA characterize the simulated soils provided by JPL. We are currently under contract to test these soils for particle size, shape, and shear strength and will also be estimating critical state parameters. The critical state parameters are considered particularly important as NASA believes it is the best formulation to demonstrate that the simulants being tested on Earth are at least as difficult, if not more challenging, than penetrating in the real Martian regolith.

The recently selected Discovery-class mission is set to launch in 2016, and its primary goal is to understand the processes that formed the rocky planets in our solar system, including Earth. In addition to the HP3, InSight’s payload will also include a seismometer instrument called SEIS, which will monitor earthquakes and other planetary core activity.

By the time you read this, we will have begun testing the first batch of soils! ■

By Jim Streier [email protected]

…Intelligent Compaction continued

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You Don’t Have to Own a Dam to Need an O&M Plan Mom: I’m sorry your trips to the bakery aren’t working out. I wouldn’t worry too much about it though, since I think red velvet was always your favorite – truthfully, I like chocolate the best.

Your comments however, got me thinking about how little attention structures sometimes receive once they’re built, and that bakery is a good example. Owners rely heavily on engineers and contractors to design and build structures that will last, which they should, but they

may not grasp the importance of post-construction operation and maintenance to achieve consistent performance over the probable (or expected, depending on who is talking) life of the structure.

While we all know that nothing lasts forever, what we don’t always appreciate is that the only time a built structure is performing at its design level is the day it’s completed – every day thereafter one or more of its components is wearing out and one day closer to repair or replacement. Neglect only speeds up that process, sometimes with more serious consequences, whether related to a mode of failure (sudden versus gradual) or mitigation option (replacement versus repair).

We all perform or retain others to perform regular or emergency operation and maintenance on many of the things we own. These activities are most regularly performed on things we are in closest proximity to and depend on the most: We change light bulbs in our lamps, fix leaks in our faucets, change the oil in our cars, etc. We are less apt to pay regular attention to the things outside our sphere of daily awareness: We may not realize that our gutters need cleaning until we find water seeping through the bedroom wallpaper, or that hornets found a home in a vent pipe until they are invading the kitchen.

The same goes for building or business owners, except on a larger scale. Owners have plenty of opportunity – and responsibility – to perform operation and maintenance activities on a number of structure components, including fire sprinkler systems, building envelope seals, etc. These building components require periodic testing for code compliance, similar to vehicles requiring regular inspections. There are also organizations that help owners track their operation and maintenance opportunities and responsibilities. The American Society of Heating, Refrigerating and Air Conditioning Engineers and Building Owners and Management Association International are two organizations that offer owners innumerable references on performance standards and codes and emergency preparedness.

Unfortunately, that kind of support is often lacking for structures outside the building envelope. The structures that are less likely to be heavily regulated from a design and construction standpoint are

Ask The Professor

By Charles Hubbard, PE, [email protected]

Charles: I have to tell you that I’m not going to buy one more of those red velvet cakes you like from that bakery over by the library. Every winter the ice by the building gets worse, and your father keeps tripping on the gaps in the sidewalk (you know he can’t see very well). It’s ridiculous, and in the summer, they have the sprinklers on in the rain. Did you work on that building? I don’t know how they haven’t noticed that the place is falling apart. Don’t they have to fix it? I wonder if they ever hired someone to check their work when the place was built – you should have been out there. I’m going to write them a letter …

– Your Mother (are you coming for lasagna on Thursday?)

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©2013 Braun Intertec Corporation

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more typically exposed to unregulated temperature, humidity, and other agents of weathering and deterioration, and are thus more likely to experience premature failure.

Structures considered particularly vulnerable include isolated foundations, such as those supporting decks, exterior slabs and pavements, and retaining structures. But the structures themselves are not the only issue – often such structures are unintentionally or carelessly put in harm’s way by virtue of excessive irrigation, improperly placed downspouts, modified grades that do not drain, clogged drain pipes, etc. (Hmm, I see a theme – water – developing here).

Unfortunately, many building and business owners are more likely to change the batteries in the employee lounge television remote than check that their irrigation system isn’t errantly targeting the building’s foundation walls for hours each day, accelerating wall block deterioration, weakening the foundation soils and contributing to frost heave issues. Too often, once discovered, performance issues become points of contention and legal battles, as only then are post-construction operation and maintenance responsibilities brought to light.

Since new projects are being designed and built every day, designers, builders, property developers and managers, insurance agents, attorneys, and others have an immediate opportunity to work more closely with owners, discussing the serviceability aspects of their building and nonbuilding components, and offering or directing them to resources on operation and maintenance.

Make a focused O&M planOperation and maintenance (O&M) plans don’t need to be complicated but do need to contain specific elements that target the unique nature or function of the structure or structure component being addressed. Each is important because the owner or owner’s agent performing the operation and maintenance task won’t likely have designed or built the structure or component.

Here’s the making of an O&M plan you can put into action:

Regulatory or ownership agreement: Assuming the structure or structural component has been properly designed and built, the owner, user, or operator of the structure or component first assumes responsibility, by regulation or agreement, to operate and maintain it in accordance with the designer’s, builder’s, and/or regulatory agency’s guidelines or requirements.

Purpose and function: In order for the owner, user, or operator to understand the relevance and importance of what he/she is assuming responsibility for, the plan should define the purpose and function of the structure or component being addressed.

Governing procedures and regulations: The plan must outline under what procedures and/or regulations the operation and

maintenance activities are performed, so that those activities are done correctly and in a consistent and timely manner. This section typically includes procedures for dealing with structural or structure component improvements or alterations, and for reporting operation and maintenance activities to cooperating personnel, firms, and agencies as required.

Operation: “Operation” refers to how a structure or structure component is supposed to operate or be operated under normal, problematic, and if necessary, emergency conditions. This section defines how the owner, user, or operator handles the working parts of the structure or component. Many of the building and nonbuilding structures identified herein, like slabs and pavements, don’t have an operational component; others like downspouts and irrigation systems do. For operational structures and components, a plan and schedule are typically set for when to test that the working parts are properly functioning, how to perform the tests, and what needs to be done based on the test results. This section should also describe conditions of critical structures and components that trigger the reporting of critical performance issues to regulatory agencies and local law enforcement authorities, as well as emergency actions.

Roof and general property drainage is often found discharging over nearby slopes with little apparent consideration for the impact such water might have on slope stability. The cost of repairing failed slopes is likely to be much greater than preventive measures.

… Ask The Professor continued

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Maintenance: This section focuses on general inspections, including what to look at and for, how the whole or parts of the structure or component should look or be performing, and what is acceptable and what is not. It also explains maintenance activities, such as routine tasks that need to be accomplished just to maintain or restore structure/component performance. Lastly, it concludes with recommended maintenance and repair materials.

Enhance long-term building performanceThe O&M plan as described here is quite comprehensive in its intent, content and detail. Developing these types of plans are often for public structures where purpose and function are so important that failure risks causing loss of life or property, or subjecting people to undesirable hardships, e.g., dams and power stations. On a simpler

scale, O&M plan components can be applied to any structure, whether it performs an operational task or not. Just the awareness that structures and structure components have a purpose and function, and need to be tested and/or maintained on a regular basis, goes far in helping owners assume responsibility for their building and nonbuilding structures. It also helps perform or retain necessary (or required) operation and maintenance tasks.

While properly designed and built structures can and should be assumed to perform for a time duration determined by industry standards or predicted by statistics; longevity is partly dependent on the owners’ acceptance and practice of operation and maintenance tasks appropriate or required for them. Designers and builders have an opportunity to help owners understand this and manage it with an O&M plan. In the future, an O&M mentality may mean that out of sight for those who design and build will not mean out of mind. – And yes, I’ll be there Thursday. ■

O&M plans are a requirement for structures like this dam, where failure would have a costly impact on life and property. We don’t often appreciate the cost of preventative inspection and maintenance until we experience the cost of “lesser” failures, like a leaky roof or burst pipe, which can be a much greater cost.

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By Jason Hanlon, PE [email protected]

In today’s society, there are some people with a perceived notion that if something is not right or broken, it must be someone else’s fault. If a person believes he is wronged, rather than take personal responsibility to fix the problem, he may consider pursuing the perceived culprit to get compensation. We could go down so many avenues with this topic, but as a professional engineer, I focus exclusively on the issues that occur in buildings, either from design defects, construction defects (both real and perceived), and unfavorable forces of Mother Nature. The latter often gets the majority of the finger pointing these days. Despite

the perceived cause of the condition, the main question insurance companies, attorneys, and other parties involved want to know is, “What really happened?”

Let’s take a recent insurance claim as an example. In this case, a grocery store reported wind damage to its existing building that apparently allowed water to penetrate the roof space, causing problems with the front masonry block wall, existing interior finish along this wall, and damage to the ceilings of the walk-in cooler and freezer. The insurance company queried, “Is it possible that the reported storm event caused the reported damage?” This question in and of itself is somewhat open-ended. You may say, sure, anything is possible, but shouldn’t the question really be, “Did the reported storm event cause the reported damage?” Even that question could produce a fairly loose answer, because the original conditions of the affected components prior to the storm event were unknown (or unseen). We would hope the owner is knowledgeable of the building and honest about the prior conditions. The problem is some commercial property owners are not in the same locale as the property and must rely on their staff for this information.

Let’s return to the question, “Is it possible the reported storm event caused the reported damage?” Answering this question

Forensics: What Really Happened? Investigating design defects, construction defects and unfavorable forces of Mother Nature

Visual observations of old damage to the front block in the parapet lead us to question if this was a possible avenue for water.

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Reverse Engineering: Determining Floor Load Capacity

Recently, Braun Intertec helped determine the floor load capacity of a new space for a client in downtown Minneapolis. The building is more than 100 years old, and there were some drawings available on the construction, but they were inconsistent with the as-built condition. The client needed to know what the floor load capacity was for this space, but the costs and logistics to do an in-situ load test made this option unreasonable. Through field verification of floor depths, some limited partial destruction exploration, topping thickness, rebar extraction, and rebar strength tests, Braun Intertec was able to “reverse engineer” the floor system and determine an allowable live load capacity for the existing floor system. This process added to the overall schedule, since Braun Intertec needed to gather pieces of information at different times to limit disruptions with the existing tenants. But in the end, it saved the client testing costs and provided them with a level of confidence in the current state of load capacity limits. The client was able to plan accordingly and eliminate some “what if” scenarios.

Braun Intertec took cores from the topside of the slab to determine compressive strength of the concrete and help “reverse engineer” the floor system.

obviously requires some background information on the building, much of which can be collected by visiting the site. When we make that visit, we want to investigate:

• Age of the structure • Type of construction • Layout of the building • Locations of bearing walls and columns • Roof and floor framing layouts • Interior finishes • Flashing and/or waterproofing details • Roof construction • Any previous repairs or remodeling • Date of the reported storm event • Date the damages were observed

The grocery store structure was more than 90 years old and constructed with masonry block exterior walls. The interior finish was a panelized, vinyl finish that allowed for easy cleaning. Excessive moisture buildup between the masonry wall and the panels caused the paneling to expand, damaging the interior molding and finish around the windows.

The roof framing consisted of hand-framed wood girders that spanned the width of the building and supported the ceiling and roof rafters. The interior layout was generally open except for a walk-in freezer and cooler area at one side of the building. The condition of the roof flashing was what would be expected for a building of this age. The flashing most likely had been replaced at some point in the life of the structure, but not recently since it was worn down due to exposure. The windows were not original to the building, and there was no flashing over the windows or doors. The damaged roofing membrane had been patched prior to our site visit.

A majority of this information would have been available over the phone or through email; however, to get a true understanding of the damage and structure’s condition, a site visit was needed by a qualified professional to confirm the extent of the alleged damage and its cause. Insurance companies and attorneys will typically request that a registered engineer and/or architect perform this review. There will be times where this information, along with photos of the conditions, are used to give an initial verbal opinion that might help with processing the claim and/or determining what additional information or access may be needed once on-site.

On-site, the condition of the grocery store’s interior paneling and finish were observed along with the exterior condition of those affected areas. The attic access area above the cooler and freezer was also observed along with the front wall above the area with reported damage. We also made arrangements to access the roof and view those areas along the front wall. Unfortunately, our visit

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occurred three months after the reported storm event, so the roofing material that was reportedly pulled away by the storm had since been replaced. There were areas of the front parapet still exposed that allowed for some visual observations, but there were no other pictures taken of the structure shortly after the reported damage and prior to the repairs.

One challenge in forensic work is timing the expert’s involvement – as noted, engineering or architectural review does not always occur soon after the causative event, when the most damage is observable. Many times, an owner may believe the case or claim is straightforward enough that it should be resolved within reason with everyone agreeing on the outcome. Basically, the owner believes, I have “problem A” because of “event B” so I should get “result C.” But regardless of whether it is a lawsuit or insurance claim, what happens frequently is the owner is offered “result D,” which may end up being a bit different than “result C.” At that point, an expert is retained to help determine why the two “results” don’t agree and whether either is appropriate.

Looking closely at the post-storm condition of the grocery store, there was one thing we immediately noticed. The reported claim damage was localized to the front of the building in what was thought to be water trapped behind the panel boards and in the masonry block, with freeze-thaw action occurring and possibly causing the damage. What we noticed was that the building was aged and weathered all around – there were cracks visible in the exterior masonry block around the entire building, not just the front,

and it was obvious that these cracks had been in place for years. It was also apparent that the building had some deferred maintenance, which may allow a minor event to cause more damage than what would normally be expected.

The further we examined the building and climbed into the attic space, it was apparent there was a plumbing line connected to the refrigeration unit for the freezer and cooler that ran over the top of these appliances. The freezer’s condensation buildup dripped and traveled along the length of the plumbing pipe to a point right over the cooler, dripping water onto the ceiling. Due to the deferred maintenance apparent elsewhere, it is believed the attic area had also been neglected, and the condition of heavy condensation dripping onto the ceiling below had been left unattended. We also noticed an absence of water staining on the interior face of the block visible from the attic space along the front wall in question that would have supported the original claim.

As we gathered information and facts from the site and other research, we began to evaluate information and data that allowed us to eliminate some of the possible causes. The condition of this particular building lead to the determination that deferred maintenance was the main culprit of the reported damage, weakening the structure to a point where even small storm events were deemed capable of impacting the structure.

Back to the question, “Is it possible that the reported storm event caused the reported damage?” The general answer is yes, it is possible, but that does not adequately address all the aspects of this case. There were some damaged areas that could have been affected by the storm. The displaced roofing material may have been due to a storm, but lacked visual evidence leaving us to rely on information provided by others. Though stormwater may have entered the space during the event causing the water damage, there was significant evidence indicating building materials were already being compromised by condensation runoff occurring along the interior plumbing line. It’s likely water was already entering the building through exterior cracks in the masonry block, missing drip edges over windows and doors, and other unmaintained building components. If additional water did get into the areas from the alleged storm event, it most likely only exacerbated an existing condition.

The question of, “What really happened?” isn’t always as straightforward and easy to pinpoint, even with the availability of detailed information. What we must rely on as industry professionals is our ability to thoroughly look at the details and piece together some general background information from our observations of both damaged and undamaged portions of structures. Providing an unbiased opinion of the conditions can help owners understand the issues observed and make the proper decisions to address conditions appropriately and fairly. ■

The plumbing line in the attic feeding the freezer below had substantial frost buildup and condensation wicking along its length.

… Forensics continued

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Dollars and Sense Positively Impact our CommunitiesFollow-up to: The Art of Brownfield Redevelopment Grant Applications

By Christopher Thompson, PE [email protected]

Braun Intertec has assisted many clients through the years with the process of completing and qualifying for grant applications, and performing investigations and response actions funded by grants. After explaining all about the process in our last issue, we thought it might be exciting to know how much grant funding is changing our communities.

This past November, the Metropolitan Council, the Minnesota Department of Employment and Economic Development and Hennepin County received applications for investigation and cleanup associated with a number of brownfield properties in the Twin Cities metropolitan area as well as out-state Minnesota.

According to the following organizations, DEED awarded approximately $5.3 million in contamination cleanup grants collectively to projects in Baudette, Eagan, Minneapolis, Hopkins, Brooklyn Center, Hutchinson and Duluth, Minn. The Met Council awarded nearly $2.4 million in Livable Communities investigation and cleanup grants to projects in Brooklyn Center, Edina, Hopkins, Mahtomedi, Minneapolis, Newport, Robbinsdale and St. Paul, Minn.

The DEED Grant program helps communities pay for assessing and cleaning up contaminated sites for private or public redevelopment. Since the inception of the program in 1995, DEED has awarded nearly $134 million in grants.

The Met Council awards about $5 million a year for brownfield cleanup, allocating funds twice a year. Since the Livable Communities program became law in 1995, the Met Council has made 357 brownfield cleanup grant awards to 45 communities, totaling nearly $96 million.

The Hennepin County Environmental Response Fund (ERF) grant program provides funding for a variety of activities at contaminated sites where the added environmental costs hinder site improvements or redevelopment. These are sites that present a threat to human health or the environment, provide community benefit from the cleanup, and lack funding from other sources. Since 2001, Hennepin County has awarded 298 ERF grants totaling $42.5 million.

While no grant awards were made by the Ramsey County Community and Economic Development/Housing and Redevelopment Authority this past round, Ramsey County has an ERF program similar to Hennepin County. Since its inception, Ramsey County awarded almost $5.7 million to 22 projects.

The ERF grants are funded by a county mortgage registry and deed tax. The state statute that provides the authority to collect funds for this program expired on January 1, 2013, and Hennepin and Ramsey County are seeking reinstatement of the authority to collect funds for ERF in the 2013 legislative session.

Without all of these funds, many of the projects that shaped our communities would not have happened. ■

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Questions, requests and comments

Charles Hubbard, PE, PGBraun Intertec Corporation11001 Hampshire Ave SMinneapolis, MN 55438Phone: [email protected]

©2013 Braun Intertec Corporation

This newsletter contains only general information. For specific applications, please consult your engineering or environmental consultants and legal counsel.

Braun Intertec Brings Home the GoldFor performing intelligent compaction on in-place soils for Trunk Highway (TH) 610 in Maple Grove, Minn., Braun Intertec received an American Council of Engineering Companies of Minnesota Grand Award and a Minnesota Society of Professional Engineers Seven Wonders of Engineering Award. Check out the front-page article for more information on the capabilities of IC.

We also received two ACEC honor awards for ISD 281 Robbinsdale Area Schools outdoor athletic facilities updates and the Anoka County Road (CR) 14 design-build project, which also won a MnSPE Merit Award.

The Anoka CR 14 project was the first county lead design-build project in the State of Minnesota, which was designed and constructed in 18 months instead of the anticipated 13 years under the traditional building process.

The innovation doesn’t stop there. The ISD 281 Robbinsdale Area Schools outdoor athletic facilities updates project involved cleanup of 6.5 acres of contaminated soil underneath the middle school’s outdoor athletic facilities, requiring removal of near surface dump materials, a cap of clean soil, and a ground-breaking soil correction technology to support a new athletic field.

Many thanks to our clients and partners for making these projects a success: Minnesota Department of Transportation, Anoka County, C.S. McCrossan, SRF Consulting Group, Inc., and ISD 281.

11001 Hampshire Ave. SMinneapolis, MN 55438

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Minneapolis 800.279.6100Bismarck 701.255.7180Cedar Rapids 319.365.0961 Dickinson 701.255.7180Duluth 218.624.4967Fargo 800.756.5955Hibbing 800.828.7313La Crosse 800.856.2098Mankato 800.539.0472 Milwaukee 262.513.2995 Minot 701.420.2738Rochester 800.279.1576Saint Cloud 800.828.7344Saint Paul 800.779.1196

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