Structural Evaluation Report - City of Oregon City · Structural Evaluation Report For ... design...

Structural Evaluation Report For

Francis Ermatinger House 619 Sixth Street

Oregon City, Oregon

February 22, 2011

11050 S.E. 145th Ave.

Happy Valley, OR 97086 p. (503) 658-3541 f. (503) 658-3549

Ms. Denise Kai February 22, 2011 Page 2 1.2 Evaluation Methodology The level of investigation for this assessment included site visits, the completion of the required Tier 1 Screening Checklists, Quick Check structural calculations, and limited Tier 2 structural analyses. The building evaluation was based on walk-through visual reconnaissance during the site visits only. Site visits were conducted on 11/23/10, 11/24/10, 11/29/10, 12/1/11, 1/13/11, 1/14/11, 1/21/11, and 1/28/11. No destructive sampling or materials testing were completed as part of this evaluation. The default values for material properties as outlined in Section 2.2 and the Checklists in the ASCE 31-03 were used in the preliminary Quick Check calculations. Both structural and non-structural building components were reviewed. The Pseudo Lateral Force procedure was used for building base shear calculations per Section 3.5.2 of ASCE 31-03. Tier 1 and limited Tier 2 analyses of the three-tiered process available in the ASCE 31-03 were completed for this building. Several serious deficiencies in the building system load path were identified early in the Tier 1 screening process. Consequently, per section 3.4 of ASCE 31-03, the design team elected to end the investigation at Tier 1 and report the deficiencies. Only a preliminary geotechnical investigation was completed per Section 4.7 of ASCE 31-03 for the same reasons. Please refer the Geological Site Hazards Section 3.2 of this report for further discussion. The Level of Performance used for this building evaluation was Life Safety (LS) as established in the ASCE 31-03. Life Safety Performance Level is defined as a building performance that may include “. . . damage to both structural and nonstructural components during a design earthquake, such that: (a) partial or total structural collapse does not occur, and (b) damage to nonstructural components is non-life-threatening.” The higher Performance Level of Immediate Occupancy (IO) was not selected because the Ermatinger House is not an essential facility such as a hospital, police station, or fire station that must be operational immediately after a seismic event. The level of seismicity for this building is “High” based on the Pseudo Lateral Force procedure used per Section 3.5.2 of ASCE 31-03. The evaluation conclusions on the standard Checklists are noted as “Compliant” (C), “Non Compliant” (NC), or “Not Applicable” (N/A) in addressing the common concerns associated with each building system. Please refer to Appendix B for completed Checklists and Appendix C for supporting calculations. “Compliant” statements indicate a detail of construction meeting the Life Safety performance objective, while “Non Compliant” statements indicate details of construction which may require a more in depth review, or may require upgrade to meet the Life Safety performance objectives. 2.0 Building Data 2.1 Building Use The Francis Ermatinger House is currently maintained by the Oregon City Parks and Recreation Department and used as a historic house and living history museum. The house is the oldest wood framed structure in Oregon City and the third oldest in the State of Oregon. 2.2 Building History The Ermatigner House was originally constructed in 1845 along the banks of the Willamette River in Oregon City. A gabled addition was added in the late 1800’s to the current north side of the house. The house was moved in 1910 from its original location to 11th and Center Street in Oregon City and installed over a concrete basement. The house was moved again in 1986 to its current location at 6th

Ms. Denise Kai February 22, 2011 Page 3 and John Adams Street. The house was installed on a new poured-in-place concrete perimeter foundation with interior post and beam floor support. A 2x6 overframed roof was added over the original flat roof on the main rectangular portion of the house as part of the 1986 relocation project. The Ermatinger House was placed on the National Register of Historic Places in 1977. It is our understanding that one or more structures with a basement were located on the 6th and John Adams site prior to the Ermatinger house being moved there in 1986. One of the earlier buildings on this site may have been the old Oregon City Police Station. The earlier structures were demolished and the site was cleared at some time prior to the Ermatinger House relocation. Portions of the Ermatinger House may be located directly over one of the earlier building footprints. A comprehensive Preservation Master Plan for the Ermatinger House was completed by Slusarenko Architecture, PC in June of 2002 for the City. The Preservation Master Plan included a cursory structural evaluation for the building. Several critical structural deficiencies were identified in the structural evaluation and mitigation measures were recommended. Pursuant to the structural recommendations in the Preservation Master Plan, Slusrenko Architecture prepared construction documents including drawings in August 2002 to mitigate the structural deficiencies identified in the structural evaluation. The structural rehabilitation included strengthening the second level floor joists on the east side of the house, adding connections between first floor beams to posts and footings below, and adding sill to foundation connection plates. To our knowledge, no significant structural rehabilitation or modifications have been implemented since the 2002 work. No drawings were available for the original construction. The City provided copies of the 2002 Preservation Master Plan, the construction drawings for the 2002 structural improvements, and roof framing plans of the 2x6 overframed roof. 2.3 Building Data The Ermatinger House is a two story wood framed structure. The original footprint is approximately 24-feet wide x 33-feet long and the northern gable roof addition is approximately 16-feet wide and 22-feet long. The overall height of the building is approximately 20-feet at the highest point on the roof. The building is classified as a “Building Type 1: Wood Light Frames (W1)” per Table 2.2 in the ASCE 31-03. Building Type 1 structures include buildings of light wood framed construction that are one or more stories. 2.4 Vertical-Force-Resisting System The vertical-force-resisting system consists of wood framed walls, floors, and roofs. The walls are constructed of 2x4 or 3x4 wood studs at approximately 20-inches on center and sheathed with 1x6 straight, horizontal wood boards on the interior and wood lap siding on the exterior. Approximately two feet of the upper walls are parapets above the roofline. The original roof framing consists of 1x6 straight wood decking supported by 2x8 joists at approximately 24-inches on center spanning north-to-south. The overframed roof installed in 1986 includes plywood sheathing over 2x6 rafters at approximately 24-inches on center spacing spanning east-to-west with a ridge running north-to-south in the center of the building. The 2x6 rafters are supported midspan by 2x4 pony walls bearing directly on the original 2x8 roof joists. The second level floor framing consists of 1x6 straight wood

Ms. Denise Kai February 22, 2011 Page 4 decking supported by various sizes of 2x and 3x joists at approximately 24-inches on center spacing spanning east-to-west from exterior walls to interior walls. The first level floor framing consist of straight wood decking supported by 2x and 3x floor joists at 24-inches on center supported by four lines of interior 6x6 and 6x8 wood beams over 6x6 wood posts set on concrete pier or slab footings. The exterior walls are supported by poured-in-place concrete spread footings around the perimeter. The exterior wall spread footings consist of 8-inch wide x 8-inches deep footings with 8-inch wide x 24-inch tall stem walls. Block outs were formed in several locations along the stem wall to facilitate the jacking and moving of the house in 1986. The stem wall block outs were infilled and grouted with Cement Masonry Unit (CMU) blocks. Reinforcing of the foundation is unknown and undocumented. A structural rehabilitation project was completed in 2002. As part of the structural rehabilitation, the original second floor joists on the east side of the house were removed and replaced with new 1-3/4” x 7-1/2” LVL floor joists spanning east-to-west from the east exterior wall to interior walls. The floor joists were installed at 8-inches on center spacing and 12-inches on center spacing over the Sitting Room and Parlor, respectively. 2.5 Lateral-Force-Resisting System The building lateral-force-resisting system consists of straight sheathed wood shear wall elements and flexible straight wood sheathed floor and roof diaphragms. The forces from the shear walls are transmitted to the ground by conventional continuous concrete spread footings. 3.0 Findings Several significant deficiencies (“Non Compliant” items) in the building system load path were observed during the site visits and completion of the Checklists. Please refer to Appendix B for the completed Checklists and Appendix C for supporting calculations. Observed building deficiencies are summarized in three main categories to follow the general organization of the ASCE 31-03 Checklists. The three main categories include Structural Components, Geological Site Hazards, and Nonstructural Components. 3.1 Structural Components Structural deficiencies and structural vulnerabilities in the building structural components were noted in the roof framing, floor framing, walls, and foundation. Structural components include elements of the building that are part of the vertical-force-resisting and lateral-force-resisting system. Vertical-force-resisting components transfer building dead loads (self-weight), floor live loads (furniture and people), and roof snow load to the foundations. The lateral-force-resisting systems transfer inertial seismic loads and wind loads from the roof/floor diaphragm, to the shear walls, and then to the foundations. 3.1.1 Roof Framing. Structural deficiencies or areas of structural vulnerabilities observed in the roof

framing are as follows: 1. Roof / ceiling joists are sagging. The existing ceiling framing (original 2x8 flat roof

framing) exhibits signs of structural distress resulting from the 2x6 overframed roof installed 1986. The current roof configuration is transferring additional roof load to the original roof joists and interior walls. This item was identified in the 2002 Preservation Master Plan.

2. Ceiling boards are sagging and dislodged resulting from Item 1 above.

Ms. Denise Kai February 22, 2011 Page 5

3. There appears to be no positive mechanical connection from the roof sheathing to the exterior walls in some locations; this is a discontinuity in the roof diaphragm connection.

3.1.2 Second Floor Framing. Structural deficiencies or areas of structural vulnerabilities observed in

the second floor framing are as follows:

1. Floor joist connections at the east exterior wall over the Sitting Room and the Parlor appear inadequate and may not meet minimum International Building Code (IBC) loading criteria. The 1-3/4” x 7-1/2” LVL ledger board supporting the floor is attached to the side of the existing 3x4 wall top plate with ½-inch diameter lag bolts. The lag bolts do not appear to have sufficient edge distance to meet wood design requirements. The ledger connection was installed as part of the 2002 Structural Improvements Project. It does not appear that the floor to wall connection conformed to the 2002 structural Improvement Drawings.

2. Floor joist connections at the west interior bearing wall over Sitting Room appear inadequate and may not meet minimum IBC loading criteria. The 1-3/4” x 7-1/2” LVL ledger board supporting the floor joists is attached directly to the 1x straight wall sheathing in some locations and into wall studs in other locations with ½-inch diameter lag bolts. The lag bolts do not appear to have enough thread embedment or are spaced too far apart to develop required load resistance. The ledger connection was installed as part of the 2002 Structural Improvements Project. It does not appear that the connection conformed to the 2002 Structural Improvement Drawings.

3. The end floor joists at the walls were cut back and/or modified at the building corners in several locations along the east wall. It appears that the framing modifications were made in previous rehabilitation projects. The framing modifications may reduce the integrity of the corner framing and the capacity of the floor diaphragm to wall connection.

4. Floor joists on the west side of house over the Dining Room and Library vary in size and spacing. Some floor joists may not be adequate to meet minimum IBC loading criteria.

5. The second floor framing over the Entry Hall is not continuous from bearing wall to bearing wall. In some locations the floor joists are cut short from the wall and are acting as cantilever members supported by the nonstructural panel wall between the Entry Hall and the Library. The floor framing over the Entry Hall may not meet minimum IBC loading criteria. Also see wall Item 3.1.4.3 below.

6. The floor is not level and is sloped in random directions throughout the second level. The floor slope may be attributed to excessive deflection in structural members or as a result of previous house relocations.

7. It does not appear that the 7” x 9-1/2” PSL floor beam over the Dining Room was installed per the 2002 Structural improvements drawings.

8. We observed no positive connection from the floor sheathing to the exterior walls in several locations; this is a discontinuity in the floor diaphragm connection.

3.1.3 First Floor Framing. Structural deficiencies or areas of structural vulnerabilities observed in the

first floor framing are as follows:

1. Floor joists to wall connections at west and east foundation walls appear inadequate in several locations. The original notched floor joists have been dislodged from their bearing seat as a result of previous building relocation or building movement. The floor


joists do not have adequate end bearing and may not meet minimum IBC loading criteria. The floor appears to be dropping in the southwest corner and may be a result of the inadequate joist to wall connection and the foundation issues described in Section 3.1.5 below.

2. Dry-rot and deterioration of wood was observed in some floor joists below the Dining Room and Library.

3. Floor framing below the Entry Hall near the stairs in the crawl space are sagging and exhibit signs of structural distress.

4. The floor is not level and is sloped in random patterns throughout the first level. The floor slope may be attributed to excessive deflection in structural members, as a result of previous house relocations, or foundation settlement. There may be some correlation to foundation settlement related to the interior bearing wall supported by pier footings discussed in Section 3.1.5.8.

5. There appears to be no positive connection from the floor sheathing to the exterior walls over a large percentage of the floor area. This creates discontinuities in the floor diaphragm connection.

3.1.4 Wall Framing. Structural deficiencies or areas of structural vulnerabilities observed in the wall framing are as follows:

1. Many of the exterior walls on the first level are not plumb. The vertical wall angle on the

first level was measured in several locations with an electronic level and angles of approximately 0.5° (1/8” per foot) to 2.0° (7/16” per foot) out-of-plumb were noted. The walls with the highest degree of slope were the east and west walls on the first level. We observed the first level wall in the Dining Room pushed out approximately 3-1/4” in one location at the base of the wall. The out-of-plumb walls are a concern because they may induce additional horizontal loads in the framing that do not normally occur in plumb walls. The out-of-plumb wall framing and associated connections may experience structural distress or movement resulting from combined vertical and lateral forces if not detailed properly. No positive mechanical connections from the floor to the wall that could resist significant horizontal loads were observed; neither the floor sheathing nor floor joists are positively attached to the wall or top plate. Reference Sections 3.1.3.1 and 3.1.3.2.

2. Exterior walls on the second level do not appear plumb. The vertical wall angle on the second level was measured in several locations with an electronic level and angles of approximately 0.3° (1/16” per foot) to 0.6° (1/8” per foot) out-of-plumb were observed. The wall angles on the second level are not as severe as the first level. See comments in Section 3.1.4.1 above.

3. Interior walls on the first and second level do not appear plumb. The vertical wall angle was measured in several locations with an electronic level and angles of approximately 0.3° (1/16” per foot) to 0.7° (1/8” per foot) out-of-plumb were observed. See comments in Section 3.1.4.1 above. Some of the interior walls are acting as bearing walls supporting floor and roof loads from above. It does not appear that all of the existing bearing walls were originally constructed as bearing walls; however, they are currently supporting significant vertical load resulting from load redistribution of inadequate floor and roof framing. Some of the out-of-plumb interior walls are at even greater risk than exterior walls because they were not originally constructed to support significant vertical load; they may not be structurally adequate to resist the induced vertical and horizontal


loads as constructed. The panel wall between the Entry Hall and Library is of special concern.

4. Wood fiber crushing was observed in the top plate to stud connection in several locations at the first level wall. The stud to top plate connection consists of a through mortise and tenon joint at the single top plate. The shelf adjacent the tenon on the stud is narrow and the resulting bearing surface appears inadequate. The mortise and tenon joint may have been adequate for the original loading conditions when constructed, but the recent rehabilitation and alterations have added extra floor and roof dead loads to these structural elements. The top plate to stud connection may not minimum IBC loading criteria.

5. The Tier 1 Checklists and supporting analyses indicate that the shear strength of the straight wood sheathing does not meet minimum requirements and is Non Compliant for shear walls.

6. Some of the shear walls are too narrow and do not meet the Quick Check height-to-width aspect ratio.

7. We did not observe positive mechanical connection between the stories to transfer shear and overturning forces through the floor.

3.1.5 Foundation. Structural deficiencies or areas of structural vulnerabilities observed in the

foundation system are as follows:

1. The concrete footing and stem walls are cracked in several locations on the east, west, south, and north sides of the building. The cracks in the foundation system appear new. The cracks are vertical and generally appear to originate at the stem wall footing and widen towards the top of the stem wall. The cracks propagate through the whole footing section and up into the stem wall adjacent to grouted Cement Masonry Unit (CMU) block outs. The cracks in the stem walls appear to extend through the whole stem wall adjacent to the block outs and are visible from both the interior crawl space and the outside wall. Crack widths vary and typically exceed 0.016-inches in the footing and widen up to 1/4-inches or more at the top of the stem wall. Many of the observed foundation cracks are active and widening at time of this report.

2. The concrete stem wall is not plumb and may have rotated in various locations along the west, east, and south side of the building. The stem wall vertical angle was measured in several locations with an electronic level and angles of up to 1.5° (5/16” per foot) out of plumb were observed. Where potentially sloping stem walls were identified, the stem walls is displaced outward at top of the wall. We did not observe noticeable differential lateral offsets in the stem wall at the vertical cracks. Localized foundation distress or rotation may be possible if the foundation system were subject to horizontal walls loads from sloped exterior walls discussed in Section 3.1.4.1 in combination with soft supporting soils. If horizontal loads are applied to the top of the concrete stem wall and they are not restrained by framing, the footing may be eccentrically loaded resulting in increased soil bearing pressures on one side of the footing in the direction of applied loads. The maximum estimated soil bearing pressure for static, symmetrically loaded foundations subject to full design dead and live load is approximately 1,100 psf. The maximum estimated soil bearing pressure for eccentrically loaded foundations subject to full design dead and live load is approximately 1,500 psf. If the soil bearing capacity is determined to be less than 1,500 psf for this site by the geotechnical engineer, footing


settlement or rotation may be possible. Further soils investigation is required to determine the actual soil bearing capacity and if foundation settlement is possible.

3. There is some evidenced of foundation settlement on the south east and south west building corners. Cracks and gaps between wall finishes were observed in these areas and the building appears to slope towards the southwest corner form the exterior. Some of the cracks and gaps are active and moving at the time of this report.

4. At least a portion of the building appears to be supported over undocumented basement fill from prior structures. It is our understanding that one or more buildings with basements may have been constructed on this site prior to the house relocation in 1986.

5. One-inch gap was observed under the footing for an 8-foot stretch at northwest corner of the building, which may be partially a result of foundation settlement.

6. Building floors are out-of-level (approximately 2.3-inches near northeast corner on lower level as measured by Pacific Geotechnical), which may be partially a result of foundation settlement.

7. Some of the 6x6 posts supporting first floor beams are not centered on the pier footings. The eccentrically loaded footings may not meet IBC design criteria.

8. Preliminary foundation analysis indicates that some of the 18-inch diameter pier footings supporting the center bearing wall between the Dining Room and Sitting Room may not meet IBC live loads requirements. The maximum estimated soil bearing pressure for the pier footings supporting the center interior bearing wall subject to dead load only is estimated to be 1,500 psf. The analysis indicates that the pier footings in this area may be at or near bearing capacity without any live load applied. The maximum estimated soil bearing pressure for the pier footings supporting the center interior bearing wall subject to full dead and live load approaches 5,000 psf. The preliminary geotechnical investigation by Pacific Geotechnical estimates the ultimate bearing capacity to be 2,000 psf to 2,400 psf. If the soil bearing capacity is determined to be less than 5,000 psf for this site in the final geotechnical investigation, bearing capacity failure or settlement may be possible. There may be some correlation with the observed first floor displacement (approximately 1 1/2-inch drop down as measured by Pacific Geotechnical) at the wall dividing the Dining Room and the Sitting Room and the deficient pier footings. Further soils investigation is required to determine the actual soil bearing capacity and if foundation settlement is possible.

9. Anchorage of sill framing to concrete stem wall appear inadequate. We observed steel anchor plates from the wood sills to the concrete foundation; however, the existing foundation anchor plates may not be installed correctly or attached to the correct framing members to adequately transfer lateral forces. This item was identified in the previous reports. The anchorage plates were installed as part of the 2002 Structural Improvements Project. It does not appear that the installed anchor plates conformed to the original construction drawings

10. We did not observe positive mechanical connections between the walls and foundation to transfer overturning forces to the foundation.

11. We noted soft, wet ground in landscaped areas during our 1/14/11 site visit. The soil “pumped” with little effort in the landscaped grass lawn near the southwest and southeast corners of the house. In addition, we observed approximately 2-inches of water at the bottom of a shallow hole (8 to 10-inches deep) under the visqueen vapor barrier in the crawl space near the southwest corner in line with the sewer service line.

Ms. Denise Kai February 22, 2011 Page 9 3.2 Geological Site Hazards A full geotechnical evaluation is recommended in the ASCE 31-03 for a wood light framed (W1) building with a High Level of seismicity. However, because of the numerous and significant deficiencies identified in the Tier 1 screening, the City elected not to complete a comprehensive geotechnical evaluation as part of the structural evaluation phase. A full geotechnical evaluation would have significantly increased the evaluation cost during the discovery phase. In lieu of a full geotechnical evaluation, the City retained the geotechnical engineering firm Pacific Geotechnical to prepare a preliminary geotechnical investigation without formal drilling and subsurface exploration. We recommend that the preliminary geotechnical investigation be updated and a final geotechnical investigation be provided before any mitigation measures for building rehabilitation are completed. The only geological site hazard identified from the Checklist for this site is excessive foundation movement and differential settlement identified in Section 3.1.5 above. 3.3 Nonstructural Component Deficiencies In addition to building structural components, nonstructural components may affect the overall performance of the building in a seismic event. Nonstructural components include elements in the building that are not part of the building lateral-force-resisting system but may still be damaged or and cause injury to occupants. Nonstructural components may include chimneys, heavy equipment, suspended ceilings, or others. We identified only one significant nonstructural component deficiency. The brick chimney on the north side of the house is not properly braced at the roof level. The unbraced brick chimney presents a potential falling hazard inside or outside of the building. In a seismic event, the chimney may move and fall over causing building damage or injury to occupants. 4.0 Recommendations As noted in the Findings, several areas of structural vulnerability and potential structural distress in the vertical-force-resisting and lateral-force-resisting systems were identified in the Tier 1 screening. The original framing may have been built to a standard of care at the time of construction, but is technically obsoleted for current standards. The deficiencies may affect the potential load carrying capabilities of the structure to perform at the Life Safety Performance level. We recommend that structural rehabilitation of the building follow this report. The structural improvements should include a complete geotechnical investigation and structural engineering design to mitigate the deficiencies identified in this report. The structural engineering design may conform to the current International Building Code or the ASCE/SEI 41-06 Seismic Rehabilitation of Existing Building Standard as allowed by the building official. For the purposes of this report, recommendations are divided into two sections. Section 4.1 includes mandatory mitigation and recommendations to improve the vertical-force-resting system to a minimum life safety level of the International Building Code (IBC). Section 4.2 includes additional recommendations to improve the lateral-force-resisting system to a minimum Life Safety Performance Level of ASCE 31-03. Seismic rehabilitation of the building in its present condition is not mandatory per the IBC and is considered voluntary. However, if significant alterations are completed to mitigate the vertical force deficiencies outlined in Section 4.1, some structural elements may require mandatory

Ms. Denise Kai February 22, 2011 Page 10 lateral force upgrades to comply with Chapter 34 – Existing Structures of the IBC. Even though seismic rehabilitation is not specifically required, it should be noted that the Non Compliant items identified in the attached Checklists are significant in that there is not a complete load path to transfer seismic inertial force between the roof/floor diaphragms, the vertical shear walls, and the foundation to meet Life Safety requirements. The building will most likely perform poorly in a seismic event and may not meet the minimum the Life Safety Performance Level of the ASCE 31-03. This may result in significant damage to the building, the contents, or injury to occupants. Damage to the building or its contents resulting from a seismic event may not be reparable. The items in Sections 4.1 and 4.2 are listed in order of importance with respect to life safety. 4.1 Vertical Force Mitigation / Recommendations The following items are recommended to provide adequate support for the vertical-force-resisting system. 1. Provide formal subsurface exploration and update the preliminary geotechnical investigation.

The additional subsurface exploration is required to determine if uncompacted fill or soft soils are present near or under the building footprint. The final geotechnical investigation should address any new issues such as uncompacted fill, soil settlement, soft soil, ground water, and provide mitigation measures. We also recommend that the report include allowable and ultimate bearing capacities for use in foundation analysis and designs in the subsequent rehabilitation phase.

2. Improve the existing foundation and mitigate soil settlement as required per the final geotechnical investigation. If additional subsurface exploration identifies uncompacted or soft soils directly under the building footprint, the existing building foundation system may require underpinning or be replaced with new foundations. The foundation improvement or replacement may include both the perimeter wall foundations and interior isolated pier and slab footings. Underpinning the foundation will require significant structural improvements to the stem wall and isolated pier footings and may not be practical. The existing perimeter foundation system is likely structurally inadequate to span between underpin anchors as a continuous grade beam because it is weakened by the stem wall block outs. The quantity or presence of concrete reinforcing in the stem walls and footings is also unknown. If new foundations are installed, they may have to extend down several feet into the existing ground to bear directly on bedrock or competent soil as recommended by the geotechnical engineer. Hand auger borings by Pacific Geotechnical indicate that the bedrock is approximately 3 to 11 feet below the ground surface. Foundation and soils mitigation measures identified in this section are preliminary and must be verified by formal subsurface exploration and a final geotechnical investigation. Alternative foundation mitigation options or repair methods may be presented after the final geotechnical investigation is completed.

3. Improve or replace deficient pier footings supporting interior bearing walls. Even if no significant soil concerns are discovered in Section 4.1.1 above, some of the existing 18-inch pier footings may be inadequate to support vertical building loads and should be replaced or additional support added. A comprehensive foundation analysis should be completed with the allowable bearing capacities provided in the final geotechnical investigation.

4. Replace all pier footings that are not centered under 6x6 posts supporting first floor beams or verity that eccentrically loaded footings meet the code requirements as constructed. Coordinate with Item 4.1.3 above.

5. Strengthen the second floor to wall connection at the east wall over the Sitting Room and Parlor. This connection may not be adequate as constructed. One possible solution may include a new


beam or a furring wall directly under the ledger beam framed against the interior face of the wall to transfer vertical loads directly to the foundation level. New beams or furring walls will be required in both the first level and crawl space below the first floor to complete the load path if this option is chosen.

6. Strengthen the second floor to wall connection on the west wall over the Sitting Room. This connection may not be adequate as constructed. One possible solution may include a new beam or a furring wall directly under the ledger beam framed against the interior face of the wall to transfer vertical loads directly to the foundation level. New beams or furring walls will be required in both the first level and crawl space below the first floor to complete the load path if this option is chosen.

7. Provide support for the first floor joists to the perimeter beam connections on east and west walls in the crawl space. Joist support may include new metal joist hangers or additional supporting beams and footings.

8. Provide additional second level floor support or add new floor joists on west side of house over Dining Room, Library, and Entry Hall. This structural improvement will require removing finishes off walls and ceilings.

9. Remove or repair the overframed 2x6 roof system installed in 1986. The new roof system should be supported by the exterior bearing walls only. One possible solution may include installing trusses that span the building width without impacting the existing interior framing. The roof repair will require a foundation analysis to determine whether the existing foundation system is adequate to support the additional roof loads.

10. Install a new floor beam in the second level floor framing over the Dining Room as recommended in the 2002 Structural Improvements. New supporting columns and footings may be required under the beam supports in the walls.

11. Adjust the exterior bearing walls so they are vertical (plumb) on the first level. If the exterior walls are adjusted to vertical, the foundation may require significant modification per Section 4.1.2 to compensate for resulting horizontal offsets between framing members. As an alternative to adjusting the walls to vertical, structural connections that are designed to resist additional forces resulting from sloping walls could be provided from the wall to foundation. Structural connections may include tension ties from the floor joists to the rim beams around the building perimeter.

12. The interior bearing walls should be adjusted so they are vertical (plumb) or install connections at the top and base of the walls that are designed to resist possible horizontal force resulting from sloping walls.

13. Verify that all interior bearing walls are structurally adequate to support vertical load from floor and roof framing.

14. Replace the decayed wood framing members under the Library and Dining Room. The rehabilitation measures identified above require geotechnical engineering, structural engineering, and rehabilitation drawings before any mitigation measures can be completed. 4.2 Seismic Mitigation / Recommendations The following items are recommended to complete the lateral-force-resisting system. These items are in addition to the recommendations in Section 4.1. 1. Install structural panel sheathing on all exterior walls under the siding to improve the shear wall

strength and connection performance. Exterior siding will have to be removed and replaced to complete this item.

Ms. Denise Kai February 22, 2011 Page 13 Attachments: Appendix A – ASCE 31-03 General Provisions Flowchart Appendix B – ASCE 31-03 Tier 1 Checklists Appendix C – Supporting Calculations Appendix D – Photographs Referenced Documents:

1. Sigma Engineering, Inc. Structural Review of Existing Second Floor Framing. November 24, 2010.

2. Sigma Engineering, Inc. Preliminary Structural Evaluation Memo. January 18, 2011. 3. Slusarenko Architecture, PC. Historic Ermatinger House & Living History Museum

Preservation Master Plan. June 2002. 4. Slusarenko Architecture, PC. Historic Ermatinger House Restoration Phase 2 Work Package

B - Structural Improvement Drawings. August 1, 2002. 5. Pacific Geotechnical. Preliminary Geotechnical Evaluation. February 11, 2011. 6. Walker / Dilorento / Yonie, Inc. Historic Ermatinger House Cursory Audit & Evaluation.

March 5, 2002.

APPENDIX A

ASCE 31-03 General Provisions Flowchart

APPENDIX B

ASCE 31-03 Checklists

Screening Phase (Tier 1)

3 - 22 Seismic Evaluation of Existing Buildings ASCE 31-03

3.7.1 Basic Structural Checklist for Building Type WI: Wood Light Frames This Basic Structural Checklist shall be completed where required by Table 3-2. Each of the evaluation statements on this checklist shall be marked Compliant (C), Non-compliant (NC), or Not Applicable (N/A) for a Tier 1 Evaluation. Compliant statements identify issues that are acceptable according to the criteria of this standard, while non-compliant statements identify issues that require further investigation. Certain statements may not apply to the buildings being evaluated. For non-compliant evaluation statements, the design professional may choose to conduct further investigation using the corresponding Tier 2 Evaluation procedure; corresponding section numbers are in parentheses following each evaluation statement.

Building System

C NC N/A LOAD PATH: The structure shall contain a minimum of one complete load path for Life Safety and Immediate Occupancy for seismic force effects from any horizontal direction that serves to transfer the inertial forces from the mass to the foundation. (Tier 2: Sec. 4.3.1.I)

C NC N/A VERTICAL DISCONTINUITIES: All vertical elements in the latera1-force-resisting system shall be

continuous to the foundation. (Tier 2: Sec. 4.3.2.4). We observed no positive mechanical connection between stories to transfer overturning and shear forces and diaphragm discontinuities at the first floor, second floor, and roof levels.

C NC N/A DETERIORATION OF WOOD: There shall be no signs of decay, shrinkage, splitting, fire damage, or

sagging in any of the wood members, and none of the metal connection hardware shall be deteriorated, broken, or loose. (Tier 2: Sec. 4.3.3.1). We observed decay in some of the first level floor joists.

C NC N/A WOOD STRUCTURAL PANEL SHEAR WALL FASTENERS: There shall be no more than 15 percent

of inadequate fastening such as overdriven fasteners, omitted blocking, excessive fastening spacing, or inadequate edge distance. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.3.3.2). Life Safety Performance Level.

Lateral-Force-Resisting System C NC N/A REDUNDANCY: The number of lines of shear walls in each principal direction shall be greater than or

equal to 2 for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.1.1) C NC N/A SHEAR STRESS CHECK: The shear stress in the shear walls, calculated using the Quick Check

procedure of Section 3.5.3.3, shall be less than the following values for Life Safety and Immediate Occupancy (Tier 2: Sec. 4.4.2.7.1):

Structural panel sheathing 1,000 plf Diagonal sheathing 700 plf Straight sheathing 100 plf

All other conditions 100 plf

The Tier 1 Quick Check Procedure indicated that shear wall loads on the first and second levels exceeded the allowable 100 plf for Straight Sheathing. Additional Tier 2 analyses confirmed that the shear walls on the first and second levels exceed allowable loads for Life Safety Performance Level.

C NC N/A STUCCO (EXTERIOR PLASTER) SHEAR WALLS: Multi-story buildings shall not rely on

exterior stucco walls as the primary lateral-force-resisting system. (Tier 2: Sec. 4.4.2.7.2) C NC N/A GYPSUM WALLBOARD OR PLASTER SHEAR WALLS: Interior plaster or gypsum wallboard shall not be used as shear walls on buildings over one story in height with the exception of the

uppermost level of a multi-story building. (Tier 2: Sec. 4.4.2.7.3)



C NC N/A NARROW WOOD SHEAR WALLS: Narrow wood shear walls with an aspect ratio greater than 2-to-l for Life Safety and 1.5-to-l for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of moderate and high seismicity. Narrow wood shear walls with an aspect ratio greater than 2-to-l for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of low seismicity. (Tier 2: Sec. 4.4.2.7.4) The majority of the shear walls comply with these provisions; however, some shear walls on the first and

second level do not meet the 2-to-1aspect ratio for the Life Safety Performance Level. C NC N/A WALLS CONNECTED THROUGH FLOORS: Shear walls shall have interconnection between

stories to transfer overturning and shear forces through the floor. (Tier 2: Sec. 4.4.2.7.5). We observed no positive mechanical connection between stories and at the foundation to transfer overturning and shear forces.

C NC N/A HILLSIDE SITE: For structures that are taller on at least one side by more than one-half story due to a sloping site, all shear walls on the downhill slope shall have an aspect ratio less than 1-to-1 for Life Safety and 1 to 2 for Immediate Occupancy. (Tier 2: Sec. 4.4.2.7.6). Level Site. C NC N/A CRIPPLE WALLS: Cripple walls below first-floor-level shear walls shall be braced to the foundation with wood structural panels. (Tier 2: Sec. 4.4.2.7.7) C NC N/A OPENINGS: Walls with openings greater than 80 percent of the length shall be braced with wood structural panel shear walls with aspect ratios of not more than 1.5-to-1 or shall be supported by adjacent construction through positive ties capable of transferring the lateral forces. (Tier 2: Sec. 4.4.2.7.8). The existing walls are sheathed with straight sheathing and the openings along some wall

lines exceed 80 percent of the wall length.

Connections C NC N/A WOOD POSTS: There shall be a positive connection of wood posts to the foundation. (Tier 2: Sec. 4.6.3.3) C NC N/A WOOD SILLS: All wood sills shall be bolted to the foundation. (Tier 2: Sec. 4.6.3.4)

We observed post installed foundation anchor plates from the wood sills to foundation; however, the existing foundation anchor plates may not be installed correctly or attached to the correct framing members to adequately transfer lateral forces.

C NC N/A GIRDER/COLUMN CONNECTION: There shall be a positive connection utilizing plates, connection hardware, or straps between the girder and the column support. (Tier 2: Sec. 4.6.4.1)



3.7.1S Supplemental Structural Checklist for Building Type WI: Wood Light Frames This Supplemental Structural Checklist shall be completed where required by Table 3-2. The Basic Structural Checklist shall be completed prior to completing this Supplemental Structural Checklist

Lateral-Force-Resisting System C NC N/A HOLD-DOWN ANCHORS: All shear walls shall have hold-down anchors constructed per acceptable construction practices, attached to the end studs. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.7.9). Life Safety Performance Level.

Diaphragms C NC N/A DIAPHRAGM CONTINUITY: The diaphragms shall not be composed of split-level floors and shall not have expansion joints. (Tier 2: Sec. 4.5.1.1). We observed diaphragm discontinuities at the

first floor, second floor, and roof levels. Wood framing members are cut back or modified at the diaphragm boundaries on the second level floor.

C NC N/A ROOF CHORD CONTINUITY: All chord elements shall be continuous, regardless of changes in roof elevation. (Tier 2: Sec. 4.5.1.3) C NC N/A PLAN IRREGULARITIES: There shall be tensile capacity to develop the strength of the diaphragm at re-entrant corners or other locations of plan irregularities. This statement shall apply

to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.7). Life Safety Performance Level.

C NC N/A DIAPHRAGM REINFORCEMENT AT OPENINGS: There shall be reinforcing around all diaphragm openings larger than 50 percent of the building width in either major plan dimension. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.8). Life Safety Performance Level. C NC N/A STRAIGHT SHEATHING: All straight sheathed diaphragms shall have aspect ratios less than 2-

to-1 for Life Safety and 1-to-l for Immediate Occupancy in the direction being considered. (Tier 2: Sec. 4.5.2.1). Less than 2-1 aspect ratio and Life Safety Performance Level.

C NC N/A SPANS: All wood diaphragms with spans greater than 24 feet for Life Safety and 12 feet for Immediate Occupancy shall consist of wood structural panels or diagonal sheathing. (Tier 2: Sec. 4.5.2.2). The roof and floor diaphragms consist of straight wood sheathing with a maximum width

of 33 feet in the east-west direction. The 33 feet exceeds the 24 feet minimum for Life Safety, but Tier 2 analyses indicate that the diaphragm Demand-Capacity Ratios meets the requirements of Figure 4-1. Diaphragm deflection calculations are recommended for further evaluation.

C NC N/A UNBLOCKED DIAPHRAGMS: All diagonally sheathed or unblocked wood structural panel diaphragms shall have horizontal spans less than 40 feet for Life Safety and 30 feet for Immediate Occupancy and shall have aspect ratios less than or equal to 4-to-1 for Life Safety and 3-to-l for Immediate Occupancy. (Tier 2: Sec. 4.5.2.3). Spans less than 40 feet and Life Safety Performance Level. C NC N/A OTHER DIAPHRAGMS: The diaphragm shall not consist of a system other than wood, metal deck, concrete, or horizontal bracing. (Tier 2: Sec. 4.5.7.1)

Connections C NC N/A WOOD SILL BOLTS: Sill bolts shall be spaced at 6 feet or less for Life Safety and 4 feet or less for Immediate Occupancy, with proper edge and end distance provided for wood and concrete. (Tier 2: Sec. 4.6.3.9). No sill bolts observed. We observed post installed foundation anchor plates from

the wood sills to foundation; however, the existing foundation anchor plates may not be installed correctly or attached to the correct framing member to adequately transfer lateral forces.



3.8 Geologic Site Hazards and Foundations Checklist This Geologic Site Hazards and Foundations Checklist shall be completed where required by Table 3-2. Each of the evaluation statements on this checklist shall be marked Compliant (C), Non-compliant (NC), or Not Applicable (N/A) for a Tier 1 Evaluation. Compliant statements identify issues that are acceptable according to the criteria of this standard, while non-compliant statements identify issues that require further investigation. Certain statements may not apply to the buildings being evaluated. For non-compliant evaluation statements, the design professional may choose to conduct further investigation using the corresponding Tier 2 Evaluation procedure; corresponding section numbers are in parentheses following each evaluation statement.

Geologic Site Hazards The following statements shall be completed for buildings in levels of high or moderate seismicity. C NC N/A LIQUEFACTION: Liquefaction-susceptible, saturated, loose granular soils that could jeopardize the

building's seismic performance shall not exist in the foundation soils at depths within 50 feet under the building for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.7.1.). Non-liquefiable soils and shallow bedrock are present at the site.

C NC N/A SLOPE FAILURE: The building site shall be sufficiently remote from potential earthquake-induced

slope failures or rockfalls to be unaffected by such failures or shall be capable of accommodating any predicted movements without failure. (Tier 2: Sec. 4.7.1.2). Level Site.

C NC N/A SURFACE FAULT RUPTURE: Surface fault rupture and surface displacement at the building site is not

anticipated. (Tier 2: Sec.4.7.1.3). No known mapped faults in the immediate site vicinity. Nearest known fault is approximately 2 miles to the northeast.

Condition of Foundations The following statement shall be completed for all Tier 1 building evaluations. C NC N/A FOUNDATION PERFORMANCE: There shall be no evidence of excessive foundation movement such

as settlement or heave that would affect the integrity or strength of the structure. (Tier 2: Sec. 4.7.2.1) We observed cracks wider than 0.016 inches in the existing poured-in-place concrete stem walls and

foundations on the north, south, west and east walls. At least a portion of the building appears to be supported over undocumented basement fill. One-inch gap observed under footing at northwest corner of the building. Building floors are out-of-level (approximately 2.3 inches maximum on lower level), which may be partially a result of foundation settlement. Further geotechnical investigation is required.

The following statement shall be completed for buildings in levels of high or moderate seismicity being evaluated to the Immediate Occupancy Performance Level. C NC N/A DETERIORATION: There shall not be evidence that foundation elements have deteriorated due to

corrosion, sulfate attack, material breakdown, or other reasons in a manner that would affect the integrity or strength of the structure. (Tier 2: Sec. 4.7.2.2). Life Safety Performance Level.

Capacity of Foundations The following statement shall be completed for all Tier 1 building evaluations. C NC N/A POLE FOUNDATIONS: Pole foundations shall have a minimum embedment depth of 4 feet for Life

Safety and Immediate Occupancy. (Tier 2: Sec. 4.7.3.1). No pole foundations.



The following statements shall be completed for buildings in levels of moderate seismicity being evaluated to the Immediate Occupancy Performance Level and for buildings in levels of high seismicity. C NC N/A OVERTURNING: The ratio of the horizontal dimension of the lateral-force-resisting system at the

foundation level to the building height (base height) shall be greater than 0.6Sa. (Tier 2: Sec. 4.7.3.2) Ratio of base to height = 24 ft / 20 ft = 1.2 > 0.6 Sa = 0.6 (0.67) = 0.40 C NC N/A TIES BETWEEN FOUNDATION ELEMENTS: The foundation shall have ties adequate to resist

seismic forces where footings, piles, and piers are not restrained by beams, slabs, or soils classified as Class A, B, or C. (Section 3.5.2.3.1, Tier 2: Sec. 4.7.3.3). Foundations are braced by Class C soils.

C NC N/A DEEP FOUNDATIONS: Piles and piers shall be capable of transferring the lateral forces between the

structure and the soil. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.7.3.4). No deep foundations and Life Safety Performance Level.

C NC N/A SLOPING SITES: The difference in foundation embedment depth from one side of the building to

another shall not exceed one story in height. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.7.3.5). Level Site and Life Safety Performance Level.



3.9.1 Basic Nonstructural Component Checklist This Basic Nonstructural Component Checklist shall be completed where required by Table 3-2. Each of the evaluation statements on this checklist shall be marked Compliant (C), Non-compliant (NC), or Not Applicable (N/A) for a Tier 1 Evaluation. Compliant statements identify issues that are acceptable according to the criteria of this standard, while non-compliant statements identify issues that require further investigation. Certain statements may not apply to the buildings being evaluated. For non-compliant evaluation statements, the design professional may choose to conduct further investigation using the corresponding Tier 2 Evaluation procedure; corresponding section numbers are in parentheses following each evaluation statement.

Partitions C NC N/A UNREINFORCED MASONRY: Unreinforced masonry or hollow clay tile partitions shall be braced at a

spacing equal to or Jess than 10 feet in levels of low or moderate seismicity and 6 feet in levels of high seismicity. (Tier 2: Sec. 4.8.1.1)

Ceiling Systems C NC N/A SUPPORT: The integrated suspended ceiling system shall not be used to laterally support the tops of

gypsum board, masonry, or hollow clay tile partitions. Gypsum board partitions need not be evaluated where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier

2: Sec. 4.8.2.1)

Light Fixtures C NC N/A EMERGENCY LIGHTING: Emergency lighting shall be anchored or braced to prevent falling during an

earthquake. (Tier 2: Sec. 4.8.3.1)

Cladding and Glazing C NC N/A CLADDING ANCHORS: Cladding components weighing more than 10 psf shall be mechanically

anchored to the exterior wall framing at a spacing equal to or less than 4 feet. A spacing of up to 6 feet is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.4.1)

C NC N/A DETERIORATION: There shall be no evidence of deterioration, damage or corrosion in any of the

connection elements. (Tier 2: Sec. 4.8.4.2) C NC N/A CLADDING ISOLATION: For moment frame buildings of steel or concrete, panel connections shall be

detailed to accommodate a story drift ratio of 0.02. Panel connection detailing for a story drift ratio of0.01 is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.4.3)

C NC N/A MULTI-STORY PANELS: For multi-story panels attached at each floor level, panel connections shall be

detailed to accommodate a story drift ratio of 0.02. Panel connection detailing for a story drift ratio of 0.01 is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.4.4)

C NC N/A BEARING CONNECTIONS: Where bearing connections are required, there shall be a minimum of two

bearing connections for each wall panel. (Tier 2: Sec. 4.8.4.5)



C NC N/A INSERTS: Where inserts are used in concrete connections, the inserts shall be anchored to reinforcing steel or other positive anchorage. (Tier 2: Sec. 4.8.4.6) C NC N/A PANEL CONNECTIONS: Exterior cladding panels shall be anchored out-of-plane with a minimum of 4 connections for each wall panel. Two connections per wall panel are permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.4.7)

Masonry Veneer C NC N/A SHELF ANGLES: Masonry veneer shall be supported by shelf angles or other elements at each floor 30 feet or more above the ground for Life Safety and at each floor above the first floor for Immediate Occupancy. (Tier 2: Sec. 4.8.5.1) C NC N/A TIES: Masonry veneer shall be connected to the back-up with corrosion-resistant ties. The ties shall have a spacing equal to or less than 24 inches with a minimum of one tie for every 2-2/3 square feet. A spacing of up to 36 inches is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.5.2) C NC N/A WEAKENED PLANES: Masonry veneer shall be anchored to the back-up adjacent to weakened planes, such as at the locations of flashing. (Tier 2: Sec. 4.8.5.3) C NC N/A DETERIORATION: There shall be no evidence of deterioration, damage, or corrosion in any of the connection elements. (Tier 2: Sec. 4.8.5.4)

Parapets, Cornices, Ornamentation, and Appendages C NC N/A URM PARAPETS: There shall be no lateral1y unsupported unreinforced masonry parapets or cornices with height-to-thickness ratios greater than 1.5. A height-to-thickness ratio of up to 2.5 is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.8.1) C NC N/A CANOPIES: Canopies located at building exits shall be anchored to the structural framing at a spacing of 6 feet or less. An anchorage spacing of up to 10 feet is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.8.2)

Masonry Chimneys C NC N/A URM CHIMNEYS: No unreinforced masonry chimney shall extend above the roof surface more than twice the least dimension of the chimney. A height above the roof surface of up to three times the least dimension of the chimney is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.9.1). The brick chimney height over the north

addition exceeds twice the least dimension of the chimney.

Stairs C NC N/A URM WALLS: Walls around stair enclosures shall not consist of unbraced hollow clay tile or unreinforced masonry with a height-to-thickness ratio greater than 12-to-1. A height-to-thickness ratio of up to 15-to-l is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.10.1) C NC N/A STAIR DETAILS: In moment frame structures, the connection between the stairs and the structure shall not rely on shallow anchors in concrete. Alternatively, the stair details shall be capable of accommodating the drift calculated using the Quick Check procedure of Section 3.5.3.1 without including tension in the anchors. (Tier 2: Sec. 4.8.10.2)



Building Contents and Furnishing

C NC N/A TALL NARROW CONTENTS: Contents over 4 feet in height with a height-to-depth or height-to- width ratio greater than 3-to-1 shall be anchored to the floor slab or adjacent structural walls. A height-to-depth or height-to-width ratio of up to 4-to-1 is permitted where only the Basic Nonstructural Component Checklist is required by Table 3-2. (Tier 2: Sec. 4.8.11.1)

Mechanical and Electrical Equipment C NC N/A EMERGENCY POWER: Equipment used as part of an emergency power system shall be mounted to maintain continued operation after an earthquake. (Tier 2: Sec. 4.8.12.1) C NC N/A HAZARDOUS MATERIAL EQUIPMENT: HVAC or other equipment containing hazardous material shall not have damaged supply lines or unbraced isolation supports. (Tier 2: Sec. 4.8.12.2) C NC N/A DETERIORATION: There shall be no evidence of deterioration, damage, or corrosion in any of the anchorage or supports of mechanical or electrical equipment. (Tier 2: Sec. 4.8.12.3) C NC N/A ATTACHED EQUIPMENT: Equipment weighing over 20 lb that is attached to ceilings, walls, or other supports 4 feet above the floor level shall be braced. (Tier 2: Sec. 4.8.12.4)

Piping C NC N/A FIRE SUPPRESSION PIPING: Fire suppression piping shall be anchored and braced in accordance with NFPA-13 (NFPA, 1996). (Tier 2: Sec. 4.8.13.1) C NC N/A FLEXIBLE COUPLINGS: Fluid, gas, and fire suppression piping shall have flexible couplings. (Tier 2: Sec. 4.8.13.2)

Hazardous Materials Storage and Distribution C NC N/A TOXIC SUBSTANCES: Toxic and hazardous substances stored in breakable containers shall be restrained from falling by latched doors, shelf lips, wires, or other methods. (Tier 2: Sec. 4.8.15.1)



3.9.2 Intermediate Nonstructural Component Checklist This Intermediate Nonstructural Component Checklist shall be completed where required by Table 3-2. The Basic Nonstructural Component Checklist shall be completed prior to completing this Intermediate Nonstructural Component Checklist.

Ceiling Systems C NC N/A LAY -IN TILES: Lay-in tiles used in ceiling panels located at exits and corridors shall be secured with

clips. (Tier 2: Sec. 4.8.2.2) C NC N/A INTEGRATED CEILINGS: Integrated suspended ceilings at exits and corridors or weighing more than 2

pounds per square foot shall be laterally restrained with a minimum of four diagonal wires or rigid members attached to the structure above at a spacing equal to or less than 12 feet. (Tier 2: Sec. 4.8.2.3)

C NC N/A SUSPENDED LATH AND PLASTER: Ceilings consisting of suspended lath and plaster or gypsum

board shall be attached to resist seismic forces for every 12 square feet of area. (Tier 2: Sec. 4.8.2.4)

Light Fixtures C NC N/A INDEPENDENT SUPPORT: Light fixtures in suspended grid ceilings shall be supported independently

of the ceiling suspension system by a minimum of two wires at diagonally opposite corners of the fixtures. (Tier 2: Sec. 4.8.3.2)

Cladding and Glazing C NC N/A GLAZING: Glazing in curtain walls and individual panes over 16 square feet in area, located up to a

height of 10 feet above an exterior walking surface, shall have safety glazing. Such glazing located over 10 feet above an exterior walking surface shall be laminated annealed or laminated heat-strengthened safety glass or other glazing system that will remain in the frame when glass is cracked. (Tier 2: Sec. 4.8.4.8)

Parapets, Cornices, Ornamentation, and Appendages C NC N/A CONCRETE PARAPETS: Concrete parapets with height-to-thickness ratios greater than 2.5 shall have

vertical reinforcement. (Tier 2: Sec. 4.8.8.3) C NC N/A APPENDAGES: Cornices, parapets, signs, and other appendages that extend above the highest point of

anchorage to the structure or cantilever from exterior wall faces and other exterior wall ornamentation shall be reinforced and anchored to the structural system at a spacing equal to or less than 10 feet for Life Safety and 6 feet for Immediate Occupancy. This requirement need not apply to parapets or cornices compliant with Section 4.8.8.1 or 4.8.8.3. (Tier 2: Sec. 4.8.8.4). Parapet wall extend over the roof approximately 2 feet.

Masonry Chimneys C NC N/A ANCHORAGE: Masonry chimneys shall be anchored at each floor level and the roof. (Tier 2: Sec.

4.8.9.2). Brick chimneys do not have positive mechanical anchorage to the structure.



Mechanical and Electrical Equipment C NC N/A VIBRATION ISOLATORS: Equipment mounted on vibration isolators shall be equipped with restraints or snubbers. (Tier 2: Sec. 4.8.12.5)

Ducts C NC N/A STAIR AND SMOKE DUCTS: Stair pressurization and smoke control ducts shall be braced and shall have flexible connections at seismic joints. (Tier 2: Sec. 4.8.14.1)

APPENDIX C

Supporting Calculations

ORIGINAL FLAT ROOF : OVERFRAMING ROOF:Metal Roofing = 2.5 PSF Roofing = 5.0 PSF1x Roof Decking = 2.3 PSF 1/2" Sheathing = 1.6 PSF2x8 @ 22" O.C. = 2.1 PSF 2x6 @ 24" O.C. = 1.0 PSF5/8" T&G Ceiling = 1.9 PSF Pony Wall = 0.4 PSFMisc. Mechanical / Electrical = 1.3 PSF Insulation = 1.0 PSF

= PSF = PSFSUB-TOTAL = 10.0 PSF SUB-TOTAL = 9.0 PSF

SLOPE CORRECTION "X:12" 0.50 1.00 PSF SLOPE CORRECTION "X:12" 1.00 1.00 PSFMISCELLANEOUS = 0.0 PSF MISCELLANEOUS = 0.0 PSFROOF DEAD LOAD : = 10.0 PSF ROOF DEAD LOAD : = 9.0 PSFROOF SNOW LOAD : = 0.0 PSF ROOF SNOW LOAD : = 25.0 PSFROOF LIVE LOAD : = 0.0 PSF ROOF LIVE LOAD : = 0.0 PSFTOTAL ROOF LOAD: = 10.0 PSF TOTAL ROOF LOAD: = 34.0 PSF

GABLE ADDITION ROOF : SECOND FLOOR, WEST :Roofing = 5.0 PSF 1x Floor Decking = 2.3 PSF1x Roof Decking = 2.3 PSF 3x8 @ 24" O.C. = 3.0 PSF2x4 @ 24" O.C. = 0.7 PSF 5/8" T&G Ceiling = 1.9 PSF5/8" T&G Ceiling = 1.9 PSF Misc. Mechanical / Electrical = 0.9 PSFMisc. Mechanical / Electrical = 1.2 PSF

= PSFSUB-TOTAL = 11.0 PSF = PSF

SLOPE CORRECTION "X:12" 9.00 1.25 PSF = PSFMISCELLANEOUS = 0.0 PSF SUB-TOTAL = 8.0 PSFROOF DEAD LOAD : = 13.8 PSF MISCELLANEOUS = 0.0 PSFROOF SNOW LOAD : = 0.0 PSF MAIN FLOOR DEAD LOAD : = 8.0 PSFROOF LIVE LOAD : = 0.0 PSF MAIN FLOOR LIVE LOAD : = 40.0 PSFTOTAL ROOF LOAD: = 13.8 PSF TOTAL MAIN FLOOR LOAD: = 48.0 PSF

SECOND FLOOR, EAST : FIRST FLOOR:1x Floor Decking = 2.3 PSF 1x Floor Decking = 2.3 PSF1-3/4" x 9-1/2" LVL @ 8" O.C. = 7.5 PSF 2x8 / 3x 6 @ 24" O.C. = 2.2 PSF5/8" T&G Ceiling = 1.9 PSF 6x8 Floor Beams = 1.5 PSFMisc. Mechanical / Electrical = 0.9 PSF Insulation = 1.0 PSF

= PSF Misc. Mechanical / Electrical = 1.0 PSF= PSF = PSF

SUB-TOTAL = 12.5 PSF SUB-TOTAL = 8.0 PSFMISCELLANEOUS = 0.0 PSF MISCELLANEOUS = 0.0 PSFMAIN FLOOR DEAD LOAD : = 12.5 PSF LOFT DEAD LOAD : = 8.0 PSFMAIN FLOOR LIVE LOAD : = 40.0 PSF LOFT LIVE LOAD : = 40.0 PSF

TOTAL MAIN FLOOR LOAD: = 52.5 PSF TOTAL LOFT LOAD: = 48.0 PSF

EXTERIOR WALL : INTERIOR WALL :Lap Siding = 2.5 PSF 3x4 @ 24" O.C. = 1.0 PSF3x4 @ 24" O.C. = 1.5 PSF 1x T&G Sheathing = 4.5 PSFInsulation = 1.0 PSF Misc. Mechanical / Electrical = 1.5 PSFMisc. Mechanical / Electrical = 2.0 PSF = PSF

PSF = PSFPSF = PSF

TOTAL EXTERIOR WALL = 7.0 PSF TOTAL INTERIOR WALL = 7.0 PSF

Design Dead and Live Loads

11101.Design Dead and Live Loads Sigma Engineering, Inc. 2/18/2011

PSUDO LATERAL FORCE 619 Sixth St., Oregon City, OR

ASCE 31-03 Section 3.5Lat: 45.355411° Long.: -122.605024°

GIVEN DATA

hn 20 Building Height, feet

N 2 Number of Stories

Occupancy Category: II Table 1-1

Site Classification: D Assumed per 20.1

Ss 0.91 g Mapped MCE Spectral ResponseAcceleration at short periods (0.2 s) *

S1 0.32 g Mapped MCE Spectral ResponseAcceleration at period of 1.0 s *

Fv 1.8 Table 3-5

Fa 1.1 Table 3-6

C 1.1 Table 3-4

Ct 0.060 Section 3.5.2.4

β 0.75 Section 3.5.2.4

* Response accelerations from USGS Earthquake Ground Parameters Version 5.0.9a Software

PERIOD

T Ct hnβ

T 0.57 sec Eq. 3-8

MAPPED SPECTRAL ACCELERATION

SD12

3Fv S1 SD1 0.38 g Eq 3-5

SDS2

3Fa Ss SDS 0.67 g Eq. 3-6

Sa1

SD1

T Sa1 0.68 g Eq. 3-4

Sa if Sa1 SDS SDS Sa1 Sa 0.67 g

__________________________________________________________________________________________________

MADE BY MDN DATE: 1/20/11 SHT NO_______

CLIENT City of Oregon City JOB N0 11101

PROJECT Ermatinger House

PSUDO LATERAL FORCE

V C Sa W Eq. 3-1

V 0.73 W for Strength Design

Vasd 0.7 C Sa W

Vasd 0.51 W for Allowable Stress Design (ASD)

__________________________________________________________________________________________________

MADE BY MDN DATE: 1/20/11 SHT NO_______

CLIENT City of Oregon City JOB N0 11101

PROJECT Ermatinger House

Total Building Weight

Item L H or W Area Load Weight(ft) (ft) (ft 2 ) (psf) (Kips)

Parapet 114 2 228 7 1.6Roof - Main 33 24 792 19 15.0Roof - Addition 24 17 408 13.8 5.6Second Level Floor - Main East 16.5 24 396 12.5 5.0Second Level Floor - Main West 16.5 24 396 8 3.2Second Level Floor - Addition 22 16 352 8 2.8Second Level Exterior Walls 114 8.5 969 7 6.8Second Level Interior Walls 111 8.5 944 7 6.6First Level Floor 1,144 8 9.2First Level Exterior Walls 168 8.5 1,428 7 10.0First Level Interior Walls 123 8.5 1,046 7 7.3Front Porch Roof 24 7 168 12 2.0Back Porch Roof 17 7 119 12 1.4

Total = 76.5V = 55.8

Total Weight Tributary to Roof Diaphragm

Item L H or W Area Load Weight(ft) (ft) (ft2) (psf) (Kips)

Parapet 114 2 228 7 1.6Roof - Main 33 24 792 19 15.0Second Level Exterior Walls 114 4.25 485 7 3.4Second Level Interior Walls 111 4.25 472 7 3.3

Total = 23.3V = 17.0

Total Weight Tributary to Second Level Diaphragm


Second Level Floor - Main East 16.5 24 396 12.5 5.0Second Level Floor - Main West 16.5 24 396 8 3.2Second Level Floor - Addition 22 16 352 8 2.8Second Level Exterior Walls 114 4.25 485 7 3.4Second Level Interior Walls 111 4.25 472 7 3.3First Level Exterior Walls 168 4.25 714 7 5.0First Level Interior Walls 123 4.25 523 7 3.7Roof - Addition 24 17 408 13.8 5.6Front Porch Roof 24 7 168 12 2.0Back Porch Roof 17 7 119 12 1.4

Total = 35.4V = 25.8

Total Weight Tributary to First Level Diaphragm


First Level Floor 1,144 8 9.2First Level Exterior Walls 168 4.25 714 7 5.0First Level Interior Walls 123 4.25 523 7 3.7

Total = 17.8V = 13.0

Total Building WeightTier 1 Analysis

11101.Seismic Loads Sigma Engineering, Inc. 2/18/2011]

V= 42.8 kips Psudo Lateral Forcek = 1.0 Structure Period Component

Level wx hx wihki Fx Vj

(kips) (ft) (kips) (kips)

3 23.3 20.0 466.0 24.3 24.32 35.4 10.0 354.0 18.5 42.81 17.8 0.0 0.0 0.0 0.0

Swx= 76.5 Swxhx= 820.0

wxhkx

Swihki

Vj = SFx Eq. 3-3b

Vertical Distribution of Force

Fx =

ASCE 31-03 Section 3.5.2.2

V Eq. 3-3a

Tier 1 Analysis

11101.Story Shear.Tier 1 Sigma Engineering, Inc. 2/18/2011

Second Level

Direction Vj Aw m vjavg = (1 / m) (Vj / Aw) vj

avg < 100 plf ?

(kips) (ft) (Table 3-7) (plf)

Transverse 24.3 51.0 4.0 119 NoLongitudinal 24.3 36.0 4.0 169 No

First Level

Direction Vj Aw m vjavg = (1 / m) (Vj / Aw) vj

avg < 100 plf ?

(kips) (ft) (Table 3-7) (plf)

Transverse 42.8 51.0 4.0 210 NoLongitudinal 42.8 56.0 4.0 191 No

Shear Stress in Shear WallsASCE 31-03 Section 3.5.3.3

Tier 1 Analysis

11101.Shear Wall.Tier 1 Sigma Engineering, Inc. 2/18/2011

V= 42.8 kips Psudo Lateral Forcek = 1.0 Structure Period Component

Level wi hi wihki Cvx Fx

(kips) (ft) (kips)

3 23.3 20.0 466.0 0.6 24.32 35.4 10.0 354.0 0.4 18.51 17.8 0.0 0.0 0.0 0.0

Swi= 76.5 Swihi= 820.0 SFx= 42.8

Fx = CvxV Eq. 4-2

wxhkx

Swihki

Vertical Distribution of Force

Cvx = Eq. 4-3

ASCE 31-03 Section 4.2.2.1.3Tier 2 Analysis

11101.Story Shear.Tier 2 Sigma Engineering, Inc. 2/18/2011

Second Level

Wall Line Vj a Lw (h / L)min QUD

b m QUD / m QCE c QCE ≥ QUD / m ?

(kips) (ft) (plf) (Table 4-8) (plf) (plf) (Eq. 4-11)

South 12.2 24.0 2.1 508 4.0 127 80 NoNorth 12.2 27.0 1.3 452 3.0 151 80 NoWest 12.2 18.0 2.0 678 3.0 226 80 NoEast 12.2 18.0 2.0 678 3.0 226 80 No

First Level

Wall Line Vj a Lw (h / L)min QUD

b m QUD / m QCE c QCE ≥ QUD / m ?

(kips) (ft) (plf) (Table 4-8) (plf) (plf) (Eq. 4-11)

South 21.4 24.0 2.4 892 4.0 223 80 NoNorth 21.4 25.0 2.0 856 3.0 285 80 NoWest 21.4 28.0 2.4 764 4.0 191 80 NoEast 21.4 30.0 3.3 713 4.0 178 80 No

a From Tier 1 Analysis (Section 3.5.2.1)b QUD = Vj / Lw

c From "Seismic Rehabilitation of Existing Buildings" ASCE 41-06 Table 80-1

Shear Stress in Shear WallsASCE 31-03 Section 4.2

Tier 2 Analysis

11101.Shear Wall.Tier 2 Sigma Engineering, Inc. 2/18/2011

Roof Level

Direction Wd D vu a

Svu D DCR b,c

(kips) (ft) (plf)

Transverse 23.3 66.0 300 19,800 0.94Longitudinal 23.3 48.0 300 14,400 1.29

Second Level

Wall Line Wd D vu a

Svu D DCR b,c

(kips) (ft) (plf)

Transverse 35.4 90.0 300 27,000 1.05Longitudinal 35.4 80.0 300 24,000 1.18

a ASCE 31-03 Table 4-2

2.1 SD1 Wd

Svu Dc Cross walls ingnored due to questionalable diaphragm to wall connections.

b DCR = Eq. 4-22

ASCE 31-03 Section 4.2.6.3.2.2Tier 2 Analysis

Diaphragm Strength

11101.Diaphragm.Tier 2 Sigma Engineering, Inc. 2/18/2011

De

ad

Liv

eIte

mD

esc

rip

tion

Lo

ad

Lo

ad

Tri

b.

DL

LL

Tri

b.

DL

LL

Tri

b.

DL

LL

Tri

b.

DL

LL

Tri

b.

DL

LL

DL

LL

Wid

thW

idth

Wid

thW

idth

Wid

th(p

sf)

(psf

)(f

t)(p

lf)(p

lf)(f

t)(p

lf)(p

lf)(f

t)(p

lf)(p

lf)(f

t)(p

lf)(p

lf)(f

t)(p

lf)(p

lf)

1.

Ori

gin

al R

oo

f fra

min

g1

02

.00

20

2.0

02

01

2.0

01

20

12

.00

12

04

.00

40

2.

Ove

rfra

min

g9

25

8.0

07

22

00

8.0

07

22

00

2.0

01

85

02

.00

18

50

8.2

57

42

06

3.

Se

con

d s

tory

wa

ll -

Ext

.7

10

.00

70

10

.00

70

10

.00

70

10

.00

70

04

.S

eco

nd

sto

ry w

all

- In

t.7

00

00

8.5

06

05

.S

eco

nd

sto

ry fl

oo

r8

40

8.3

31

04

33

37

.50

60

30

02

.00

16

80

2.0

01

68

01

6.5

01

69

66

07

.F

irst

leve

l wa

ll -

Ext

.7

8.5

06

08

.50

60

8.5

06

08

.50

60

08

.F

irst

leve

l wa

ll -

Int

70

00

08

.50

60

9.

Fir

st le

vel f

loo

r8

40

5.0

04

02

00

6.0

04

82

40

2.0

01

68

02

.00

16

80

4.5

03

61

80

10

.P

orc

h R

oo

f1

22

50

00

00

03

.00

36

75

00

11

.S

tem

Wa

ll1

50

1.3

32

00

1.3

32

00

1.3

32

00

1.3

32

00

01

2.

Fo

otin

g1

50

0.8

91

34

0.8

91

34

0.8

91

34

0.8

91

34

0F

ram

ing

DL

=3

66

33

03

00

33

64

38

Fo

un

da

tion

DL

=3

33

33

33

33

33

30

Flo

or

LL

=5

33

54

01

60

16

08

40

Sn

ow

LL

=2

00

20

05

01

25

20

6T

ota

l w/o

Fo

un

da

tion

=1

,09

91

,07

05

10

62

11

,48

5T

ota

l w/ F

ou

nd

atio

n =

1,4

32

1,4

03

84

39

54

1,4

85

Be

ari

ng

Wa

ll T

hic

kne

ss =

8.0

in0

.67

ft8

.0 in

0.6

7 ft

8.0

in0

.67

ft8

.0 in

0.6

7 ft

5.5

in0

.46

ftF

oo

ting

Wid

th =

16

.0 in

1.3

3 ft

16

.0 in

1.3

3 ft

16

.0 in

1.3

3 ft

16

.0 in

1.3

3 ft

18

.0 in

1.5

0 ft

Fo

otin

g /

Sla

b T

hic

kne

ss =

6.0

in0

.50

ft6

.0 in

0.5

0 ft

6.0

in0

.50

ft6

.0 in

0.5

0 ft

10

.0 in

0.8

3 ft

Co

ncr

ete

Co

mp

ress

ive

Str

en

gth

, psi

=2

,50

02

,50

02

,50

02

,50

02

,50

0D

esi

gn

Allo

w3

Un

ityD

esi

gn

Allo

w3

Un

ityD

esi

gn

Allo

w 3

Un

ityD

esi

gn

Allo

w3

Un

ityD

esi

gn

Allo

w3

Un

ityA

llow

ab

le B

ea

rin

g, p

sf =

1,0

74

2,0

00

0.5

41

,05

22

,00

00

.53

63

22

,00

00

.32

71

52

,00

00

.36

5,0

41

2,0

00

2.5

2F

act

ore

d A

xia

l Lo

ad

, plf

=1

,79

11

,75

91

,04

01

,12

11

1,8

39

Fa

cto

red

So

il B

ea

rin

g, p

sf =

1,3

44

1,3

19

78

08

41

5,2

62

Fle

xure

, kip

-ft=

0.0

70

.40

0.1

90

.07

0.4

00

.18

0.0

40

.40

0.1

10

.05

0.4

00

.12

1.0

72

.40

0.4

5S

he

ar,

kip

=-0

.22

1.9

20

.00

-0.2

21

.92

0.0

0-0

.13

1.9

20

.00

-0.1

41

.92

0.0

0-2

.47

5.7

60

.00

No

tes:

1.

Typ

ica

l Ste

m W

all

= 2

'-0"

Ta

ll x

8"

Wid

e2

. T

ypic

al F

oo

ting

= 1

'-4"

Wid

e x

8"

Th

ick

3.

Pro

ba

ble

ulti

ma

te b

ea

rin

g c

ap

aci

ty p

er

Pre

limin

ary

Ge

ote

chn

ica

l Re

po

rt b

y P

aci

fic G

eo

tech

nic

al d

ate

2/1

1/1

1.

Ce

nte

rIn

teri

or

Be

ari

ng

Wa

ll

Fra

ncis

Erm

atin

ger

Hou

seE

stim

ated

Fou

ndat

ion

Load

s

So

uth

Ext

eri

or

Wa

llE

ast

Ext

eri

or

Wa

ll

Plain Concrete Footing Analysis

Service Loads

We

stE

xte

rio

r W

all

No

rth

Ext

eri

or

Wa

ll

11

10

1.F

ou

nd

atio

n L

oa

ds

Sig

ma

En

gin

ee

rin

g, I

nc.

2/1

8/2

01

1

APPENDIX D

Photographs

1

Second Floor Joist Connection on East Exterior Wall in Parlor Section 3.1.2.1

Second Floor Joist Connection on West Interior Wall in Parlor

Section 3.1.2.2

2

First Floor Joist to Wall Connection at East Wall

Section 3.1.3.1

First Floor Joist to Wall Connection at West Wall

Section 3.1.3.1

3

First Floor Joist to Wall Connection and Decay at West Wall

Section 3.1.3.1 and Section 3.1.3.2

Crack in Foundation Stem Wall on East Wall and Anchor Plate

Section 3.1.5.1 and Section 3.1.5.9

4

Crack in Foundation Stem Wall on South Wall

Section 3.1.5.1

6x6 not Centered Pier Footing

Section 3.1.5.7

Structural Evaluation Report - City of Oregon City · Structural Evaluation Report For ... design...

Documents

Transcript of Structural Evaluation Report - City of Oregon City · Structural Evaluation Report For ... design...