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HomeMy WebLinkAbout01/17/2006, C3 - APPROVE CONTRACT WITH URS FOR SEISMIC ANALYSIS OF SALINAS DAM council °g°� i-l'l - Oro j ac,Enaa 12EpoRt rem Numbv w� CITY OF SAN LUIS OBI SPO FROM: John Moss, Utilities Director Prepared By: Gary Henderson, Water Division Manager SUBJECT: APPROVE CONTRACT WITH URS FOR SEISMIC ANALYSIS OF SALINAS DAM CAO RECOMMENDATION 1. Approve the contract with URS Corporation (URS) for seismic analysis of the Salinas Dam in the amount of$225,989 and authorize the Mayor to execute the contract. 2. Approve transferring $230,000 from existing project balances that are either completed or not proceeding as originally anticipated in order to fund this work, including $4,011 for contingencies. DISCUSSION The Salinas Dam was constructed in 1941 by the federal government to meet the water supply needs of Camp San Luis Obispo and secondarily, for the increasing water needs of the City of San Luis Obispo. The dam was constructed to meet the federal standards at the time but design standards have changed over the years. Based on these changes, a number of seismic analyses of the dam have occurred since construction with the most recent update completed by URS in June of 2000. This report provides the background relative to the need to undertake an additional "state of the art" structural analysis of the dam based on recent discussions with the State Division of Safety of Dams (DSOD). Background The Salinas Dam serves as the City's primary water supply with Whale Rock Reservoir used as a secondary source. The facility is owned by the federal government with oversight responsibilities resting with the U.S. Army Corps of Engineers (Corps). The City of San Luis Obispo has the only water rights permit from the State Water Resources Control Board for use of water from the reservoir. In the past there were two other permits but these permits have been revoked due to lack of use of the water allowed by the permits. The City of San Luis Obispo has a license with the Corps that was originally granted in 1943 (amended many times since) that allows the City to use the dam and pipeline facilities for water deliveries. The license requires that the City pay all costs associated with operations and maintenance of the dam and delivery facilities. The County of San Luis Obispo Flood Control and Water Conservation District (District) has a lease with the Corps for the actual operations and maintenance of the dam, pipeline facilities and associated property. In addition, the County of San Luis Obispo has a lease agreement which allows for recreation activities at the lake. Salinas Dam Seismic Analysis Page 2 Ownership of Salinas Reservoir and Property The federal government (Corps) has been interested for more than 30 years in transferring ownership of the dam, conveyance facilities, and the surrounding 4,400 acres of land to a local agency. The dam no longer serves any federal purpose, therefore the Corps does not want to continue their involvement in the oversight of the facilities. The potential transfer of ownership of the dam is the primary reason for pursuing the additional seismic analysis recommended in this report. The transfer of ownership of the dam from the federal government to a local agency will require that the dam meet the design standards of the DSOD. City and County staff have been meeting over the past year with the Corps to discuss moving the ownership transfer forward. Ownership transfer will require a number of studies and actions. These include NEPA documentation (similar to CEQA process), cultural resources evaluation, hazardous materials evaluation, and possible special legislation. During meetings in early 2005, the issue of the dam meeting the State DSOD guidelines was determined to be the critical component in the process for property transfer. If the dam needs modifications to meet State standards, the magnitude of the costs and who would pay for them will be critical to the negotiations between the Corps, City and County. Agreements between all parties will be necessary to allow the transfer, likely to the County of San Luis Obispo. Previous Studies The seismic stability of the dam has been studied by the Corps (1943, 1978), United States Bureau of Reclamation (1973), Woodward Clyde Consultants (1989) and most recently by URS (2000). The latest study (2000) based on new earthquake information concluded that stresses at some locations in the dam would exceed design levels,but the occurrences were limited in extent and duration and judged acceptable. The report concluded "that the dam with the reservoir level at its present maximum operating level (elevation 1,300 ft), should be able to withstand the maximum credible earthquake with no catastrophic failure." In early 2005, a meeting with DSOD, City, and Corps staff was held to discuss review of the available information. A representative from URS who was involved in the preparation of the 2000 analysis was also in attendance at the meeting. The meeting discussed the background of the Salinas dam, the desire to transfer ownership to a local agency, the need to insure that the dam meets State standards before the dam is transferred, and the strategy for involving DSOD at this point. It should be noted that DSOD has no jurisdictional powers at this time since the dam falls under federal dam standards. The Chief of the DSOD agreed to have his staff undertake their own independent analysis of the dam. Several months later, a second meeting was held to discuss the DSOD analysis. The seismic analysis prepared by DSOD closely matched the URS analysis but based on new criteria published in 2003, the dam does not meet current standards. The Division Chief did indicate that DSOD would be willing to accept a"non-linear"analysis for the concrete arch dam at this time. A "non-linear" analysis has recently become accepted and can more accurately reflect the performance of concrete arch dams in an earthquake event. C'3-2 Salinas Dam Seismic Analysis Page 3 Strategy for DSOD Approval There are two different approaches that could be pursued to determine if the existing dam meets DSOD requirements. The first would involve removing concrete core samples from the dam and performing tests to determine the physical properties (i.e. strength) for use in the original computer analysis. While this approach would likely be less costly than the proposed non-linear analysis, it is highly unlikely that the tested concrete strength would be significantly higher than that assumed in the analysis to change the overall results. This conclusion was shared by our technical consultants at URS and high level DSOD staff. The recommended approach involves,undertaking a non-linear analysis of the dam structure under various seismic loading events. URS staff have prepared the previous two structural analyses and have a significant knowledge base relative to this dam. Based on their in-depth knowledge, past involvement in the project, and ability to prepare the specialized analysis, staff recommends sole sourcing the contract to URS.. This specialized analysis will be one of the first non-linear arch dam analysis used by DSOD to evaluate the structural integrity of a dam under their jurisdiction. This type of analysis is very complicated and requires strong technical judgment in the evaluation of the results. For these reasons, a staged work plan has been developed to insure acceptance between URS technical staff and DSOD staff in the basis and interpretation of the analysis. In addition to the seismic analysis of the dam structure, the left abutment(spillway side)of the dam will be evaluated for potential movement of the rock masses. Possible Additional Analysis Depending on the conclusions of the non-linear analysis, additional concrete testing of the existing dam structure may be necessary. The analysis will likely identify specific locations for core samples which would reduce the level of testing previously identified. Why should the City complete the new non-linear analysis? Regardless of whether the property is transferred to a local agency, it would be prudent to analyze the structure to determine the level of protection provided during an earthquake event. The.costs associated with operations, maintenance, and other related costs are required to be paid by the City under the terms of the agreement with the Corps. Completion of this analysis now, under a cooperative relationship with the Corps.and the City, will ensure the protection and continued operation of the City's primary water supply and will identify any required remedial action with the greatest degree of accuracy. FISCAL IMPACT The compensation associated with the scope of work outlined in the contract with URS is $225,989. An additional $4,011 is recommended to be approved to fund any associated expenses with this project, for a total approved project budget of$230,000. G3 Salinas Dam Seismic Analysis Page 4 While this study was not included in the Water Fund's Capital Improvement Plan, funding is available from other water capital projects that are either completed or not proceeding as originally anticipated: Salinas Reservoir Expansion $72,501.73 Groundwater Development $150,000.00 Miossi Road Easement—Reservoir#1 $7,498.27 Tota[ $230,000 Salinas Seismic Study(Spec#90623) $225,989 Contingencies 4,011 Tota[ $230,000 ALTERNATIVES 1. Do Nothing: The Council could decide not to proceed with the additional analysis. Since the Corps is very interested in moving forward with the ownership transfer, this could place an obstacle in that process. The Corps could take several paths including initiating their own studies and requiring payment from the Salinas budget (County) or other more drastic measures. This alternative is not recommended. 2. Concrete Core Sampling: The Council could decide to proceed with the concrete core testing of the existing dam prior to additional analysis. This option is not recommended because it is very likely that the non-linear analysis would still have to be undertaken. In addition, without the results of the non-linear analysis, a more extensive and costly core sampling program will be required.. ATTACHMENTS 1. Agreement with URS for Salinas dam Non-Linear Dynamic Analysis Attachment 1 AGREEMENT THIS AGREEMENT is made and entered into in the City of San Luis Obispo on this day of , by and between the CITY OF SAN LUIS OBISPO, a municipal corporation, hereinafter referred to as City,and URS CORPORATION,hereinafter referred to as Contractor. WITNESSETH: WHEREAS, the City wants to undertake'a more detailed structural analysis of the existing Salinas Dam to evaluate the structure relative to State Division of Safety of Dams regulations. WHEREAS,URS Corporation has prepared the previous structural analysis for the Salinas Dam WHEREAS, Contractor is qualified to perform this type of service and has submitted a proposal to do so which has been accepted by City. NOW THEREFORE, in consideration of their mutual promises, obligations and covenants hereinafter contained,the parties hereto agree as follows.: 1. TERM. The term of this Agreement shall be from the date,this Agreement is made and entered,as first written above,until acceptance or completion of said services. 2. CITY'S OBLIGATIONS. For providing services as specified in this Agreement, City will pay and Contractor shall receive therefor compensation in a total sum not to exceed$225,989. 4. CONTRACTOR'S OBLIGATIONS. For and in consideration of the payments and agreements hereinbefore mentioned to be made and performed by City, Contractor agrees with City to provide services as set forth in Exhibit A attached hereto and incorporated into this Agreement. Contractor further agrees to the contract performance terms as set forth in Exhibit B attached hereto and incorporated into this Agreement. 5. AMENDMENTS. Any amendment, modification or variation from the terms of this Agreement shall be itrwriting and shall be effective only upon approval by the City Administrative Officer of the City. I I Agreement Page 2 6. COMPLETE AGREEMENT. This written Agreement, including all writings specifically incorporated herein by reference, shall constitute the complete agreement between the parties hereto. No oral agreement, understanding, or representation not reduced to writing and specifically incorporated herein shall be of any force or effect, nor shall any such oral agreement, understanding, or representation be binding upon the parties hereto. 7. NOTICE. All written notices to the parties hereto shall be sent by United States mail, postage prepaid by registered or certified mail addressed as follows: City City of San Luis Obispo Attn: Gary Henderson 879 Morro Street San Luis Obispo,CA 93401 Contractor URS Corporation Attn: 'Mr.David Hughes 1333 Broadway,Suite 800 Oakland,CA 94612 8. AUTHORITY TO EXECUTE AGREEMENT. Both City and Contractor do covenant that each individual executing this agreement on behalf of each party is a person duly authorized and empowered to execute Agreements for such party. IN WITNESS WHEREOF, the parties hereto have caused this instrument to be executed the day and year first above written. CITY OF SAN LUIS OBISPO,A Municipal Corporation By: David F.Romero,Mayor APPROVED AS TO FORM: CONTRACTOR By: Jo .Lowell, City Attorney c3-� Exhibit A SCOPE of WORK SALINAS RESERVOIR NON-LINEAR DYNAMIC ANALYSES Salinas Dam is currently a US Army Corps of Engineers (COE) facility that is operated by the County of San Luis Obispo Flood Control and Water Conservation District (County). The City of San Luis Obispo pays for the County's operation costs and utilizes water available from the reservoir under the terms of the State Water Resources Control Board water rights permit. The potential future transfer of ownership of this facility from the Federal Government to a local agency will bring the dam under the jurisdiction of the California Dept of Water Resources, Department of Safety of Dams(DSOD). To assess the implications of such a transfer,the City submitted a 2000 URS report on the stability of the dam to DSOD for review and comment. In a meeting in Sacramento on July 20, 2005,DSOD presented their review comments to the City. They concluded that the stresses computed by existing linear-elastic analyses were sufficiently high relative to the estimated dynamic tensile strength of the concrete,that a non-linear analysis would be necessary to more accurately estimate the seismic stability of the dam. DSOD stated that they were now willing to accept the results of a non-linear analysis. This scope of work describes the proposed non-linear time history analyses of the dam and abutments. The foundation stability will be assessed with the spillway fault included in the right abutment foundation. I Previous Studies The seismic stability of dam has been studied by the COE (1943, 1978),United States Bureau of Reclamation(1973), Woodward Clyde Consultants (1989) and most recently by URS (2000). The URS study used a linear-elastic time history finite element analysis(FEA). A synthetic time history spectrally matched to an 84`h percentile target spectrum was developed for a maximum credible earthquake (MCE) of moment magnitude (M) 7.5 on the Rinconada fault, which passes within 1.7 km of the dam. The study concluded that in localized areas of the dam,both arch and cantilever stresses would exceed the estimated dynamic tensile strength of the concrete. The limited extent and duration of these excursions were however judged to be acceptable and the report concluded that the dam with the reservoir level at its present maximum operating level(El 1,300 ft), should be able to withstand the MCE with no catastrophic failure. In 2005,DSOD reviewed the URS report and ran an independent linear-elastic time history analysis based on a 67`s percentile response spectrum for the MCE on the Rinconada fault. In evaluating the performance of the dam,DSOD used the recently published COE damage criteria presented in Chapter 4 of EM 1110-2-60511 (22-Dec-03). Under this criteria,the non-linear response of the arch computed from a linear analysis will suffice if the computed demand capacity ratios (DCR) are less than (<) 2, overstressed areas (DCR greater than (>) 1) constitute less than 20 percent of the dams surface area and cumulative inelastic durations falls below the performance curve presented in the EM 1110-2-6051. These performance thresholds were exceeded in DSOD's analyses, suggesting that significant and repeated opening and closing of the dams four(4) vertical contraction joints would occur. Therefore to accurately assess the dam's seismic adequacy the dam would need to be analyzed using a non-linear time history analysis. Engineering and Design - Time-History Dynamic Analysis of Concrete Hydraulic Structures 1 Goa —/ Exhibit A II. Dam Description and Non-linear Response The dam is a constant angle arch designed to meet the COE standards at the time of construction in 1941-42. The dam is 135 feet high with the arch varying in length from 140 feet at the base to 305 feet at the crest. The thickness varies from 13.6 feet at the base to 8 feet at the crest. The arch barrel is keyed to a footing block poured into an excavated trench in the sandstone rock. The arch was built as cantilever monoliths separated by four vertical keyed,but ungrouted, contraction joints; one at arch centerline, one each at the quarter points, and one at about the one-eighth point on the east(left abutment) side. The left(east) abutment thrust block is embedded into rock and is separated from the arch by a contraction joint. The right abutment thrust block is located at the west end of the arch and is adjacent to the spillway. Since the contraction joints between the monoliths cannot transfer appreciable tension, the joints will open and close as the as the dam responds to the earthquake ground motions. Joint openings release arch tensile stresses and transfers the load to the cantilevers. The resulting increase in cantilever stresses may result in the tensile capacity of the lift lines to be exceeded,potentially resulting in horizontal cracks developing in the cantilevers. The open contraction joints and cracked lift lines may combine to subdivide the arch into partially free cantilever blocks and any failure mode of the dam would likely involve the stability of these partially free blocks. For moderate contraction joints openings the partially free cantilever blocks may remain stable through interlocking with adjacent cantilevers. If however contraction joint openings become excessive, the free cantilever may become unstable leading to failure of the arch. Thus in a non-linear analysis the extent of joint opening and cracking of the lift lines, and the non-recoverable movement of discrete blocks bounded by the failed joints will control the overall stability of the arch. Evaluating the seismic stability of the dam will involve kinematically demonstrating that the arch will not form a viable collapse mechanism. The stability and potential sliding displacement of the rock blocks formed by the rock mass discontinuities in the right abutment will be evaluated. The discontinuities are the bedding and primary and secondaryjoint sets identified in the 2000 URS report with the inclusion of the spillway fault as discussed by DSOD in their July presentation. The proposed nonlinear arch analyses will be based on no rock block movement occurring. However, if the analyses indicate that displacement or sliding of the blocks is possible, stabilization measures will be identified to prevent the movement rather than assessing the affect of the movements with a more complex coupled nonlinear analysis. Stabilization measures would likely involve installation of rock anchors into the rock mass. III. Scope of Work and Task Descriptions The work will be split into the following three stages. 1. Work Plan 2. Linear and Basic Nonlinear FEM Analysis 3. Detailed Nonlinear Analyses STAGES 1 &2: Development of a detailed work plan in Stage 1 and the basic nonlinear analysis in Stage 2 are intended to form the basis of discussions with DSOD. The objective of these discussions will be to reach agreement with DSOD on both the methodology for the 3-D nonlinear finite element analysis (FEA) and on how the results of the analysis will be interpreted. This staged approach is important since this will be one of the first nonlinear arch dam analysis used by DSOD to evaluate the structural integrity of a jurisdictional dam. 2 C3-� Exhibit A The work plan prepared in Stage 1 will describe the proposed 3-D nonlinear FEA computer model, the approach that will be used to model the foundation and dam/reservoir interaction,the performance criteria and the methodology for interpreting the nonlinear results and evaluating the stability of the dam. The work plan will also present the approach to dealing with the jointing in the dams left abutment The basic nonlinear analysis in Stage 2 would demonstrate the procedures described in the work plan. The basic analysis would involve developing the nonlinear FEA computer model, computing the static stresses and then analyzing the dynamic response of the dam to a spectrum-matched (synthetic)time history. The 67`h percentile response spectrum proposed by DSOD will be used as the target spectrum after its acceptability has been approved by DSOD. A meeting would be held with DSOD after each of these first two stages to present the work plan and the results on the initial nonlinear analyses. The meetings would be interactive with DSOD and their subconsultant with the objective of reaching consensus and agreement at the meeting. STAGE 3: The third stage would entail incorporating any agreed upon revisions to the FEA computer model, and then running more detailed analyses that may include transient thermal analysis, sensitivity analyses and potentially running the FEA model using a series of amplitude modified(scaled)natural earthquake records. The analysis results and dam evaluation will be documented in the report. Mr. Howard Boggs will be involved throughout the project to review the assumptions (i.e. finite element model, material,criteria, etc), analysis methodology(i.e. approach to non-linear simulation,method of evaluating failure modes, etc.) and the results (i.e. stresses, deflections, forces, structural behavior). At the end of the project Mr. Boggs will review the draft and final reports. Mr. Boggs is a consultant to URS who has over 40 years experience in the design, analysis, and construction of concrete arch dam including 28 years with the Bureau of Reclamation in Denver; 23 of which were spent performing the structural design and analyses for over 40 concrete arch dams. He was Section Head for the Bureau of Reclamation Concrete Dam Analytical Design Section for 5 years. 3 G� — ! Exhibit A The work has been subdivided into the 8 main tasks summarized below and described in the following text. Budget for each task is presented in Table 1. STAGE 1 1. Work Plan. -Develop work plan -Site visit and meet with DSOD STAGE 2 2. Basic nonlinear analysis -Develop finite element analysis computer model. -Run static stress analyses. -Develop spectrum matched acceleration time history and run linear and nonlinear time history analyses. A series of steps -Evaluate Arch Stability. 3. Evaluate Right Abutment 4. DSOD Meeting/Workshop STAGE 2 5. Incorporate Workshop Modifications Incorporate agreed upon modifications to the FEA model and develop three (3)amplitude scaled natural acceleration time history records. 6. Detailed Nonlinear Analysis Run static,transient thermal and three linear and nonlinear time history analyses. Evaluate arch stability. 7 Final Report 8 Proiect Management STAGE 1 I Work Plan ose: The initial activity will be to produce a detailed work plan that will describe the methodology used in the finite element analysis (FEA), in particular the non-linear assumptions used to simulate the contraction joints and foundation interface. The work plan will also discuss the consequence of exceeding the lift joint tensile strengths if partially free cantilevers develop during the seismic event. The work plan will describe how the results of the analysis will be interpreted and how the consequence will be evaluated. After review by the City,the work plan will be submitted to DSOD for their review. A meeting will be arranged with DSOD to discuss the work plan and agree on potential modifications. In conjunction with the first meeting with DSOD, a site visit will be arranged with the project manager,project structural engineer and peer reviewer to inspect the dam and evaluate the condition of the contraction joints, lift lines and foundation conditions. This task will also provide the opportunity to meet with the City's staff in preparation for the meeting with DSOD. 4 Exhibit A Preparation of the work plan will include reviewing the background data and previous analyses, including material properties, foundation conditions and uplift pressures. Analysis parameters will be selected(static and dynamic) for the concrete, foundation bedrock, dam foundation interface and the vertical contraction joints.. Deliverable: Draft and Final Work Plan. 2. Basic Nonlinear Time History Analysis 2.1 URS will develop a three-component set of spectrum-matched acceleration time histories using the 67`h percentile target response spectra for the Rinconada fault proposed by DSOD and as presented to the City during the July 20, 2005 meeting in Sacramento. Agreement will be obtained from DSOD on the use of this spectrum. 2.2 A three-dimensional FEA computer model of the dam will be developed using the computer program ANSYS. The objective is to develop a basic mathematical model that will simulate the nonlinear behavior of the dam and foundation and can be used to predict potential failure modes. To minimize cost and complexity,the foundation rock will be modeled without mass and with the assumption that no sliding of the blocks in the right abutment occurs. The effects of the dam-reservoir interaction will be modeled with added mass coefficients. More sophisticated analyses that incorporate the inertia and damping properties of the foundation, potential displacement of the blocks in the right abutment move and a liquid mesh to model the reservoir are not considered warranted. The model will include non-linear contact elements to simulate the vertical contraction joints in the dam and the interface between the dam and foundation. The contact elements will permit compressive forces to develop,but will not transmit tensile forces. The elements will carry shear forces when in tension to simulate the shear keys on the contraction joints. The FEA will have the ability to apply uplift pressures along the dam/foundation contact and to evaluate cracking at the interface. 2.3 Static stress in the dam and foundation with the reservoir at maximum normal stage(El 1,300) will be computed using the FEA model. In the subsequent dynamic analysis, the total stress at any point in the dam for any increment of time is equal to the static stress plus the instantaneous dynamic stress. 2.4 A linear analysis will be performed to establish a basis for evaluation of subsequent nonlinear analyses and to compare with the existing URS and DSOD analyses. The maximum horizontal component of the spectrum-matched record will be oriented in the upstream- downstream direction and lesser component in the cross-canyon direction. The analysis will use the FEA model with the non-linear elements modified to respond linearly. Reservoir/dam interaction effects will be simulated using the Generalized Westergaard's Theory for added mass. 2.5 A stepped progression from linear to full non-linear behavior will be employed to validate the ANSYS FEA model. The process will progressively add non-linearity(i.e.joint opening, and dam/foundation interface behavior)to the linear model,until the full non-linear model is produced. This methodical change from linear to non-linear action permits the non-linear response of the arch to be more clearly understood. If the stepped analyses show an abrupt change in the arch response, the reasons for that observation will be further evaluated to verify that the finite element model is properly simulating the behavior of the arch. Sensitivity 5 %� I \ 1 J Exhibit A analysis of critical modeling and parameter assumptions will be used to further validate the ANSYS computer model. DSOD has indicated that such proposed stepped progression from the linear to full non-linear computer model will be acceptable verification of the non-linear response computed by ANSYS and that they do not expect an independent verification FEA model to be run. DSOD will run their own nonlinear analyses using the computer program SAP to compare with the results developed by ANSYS. Results from the full nonlinear analyses will include structural deformations, arch and cantilever stresses, and normal and shear forces on the foundation and abutment. The arch and cantilever stresses will be evaluated against the estimated dynamic strength of the concrete, and an assessment will be made as to the extent of potential cracking along lift lines. Plots of maximum arch and cantilever stresses for upstream and downstream faces of dam will be developed along with arch and cantilever stress distributions at selected times during the earthquake. The extent of contraction joint opening and the potential cracking of the lift lines will be evaluated and the non-recoverable movement of the free cantilever blocks bounded by the failed lift joints and open contraction joints will be evaluated with spreadsheets using Microsoft Excel. Plots of the deflected shape and contraction joints opening will be produced. The results will be transformed into the normal and shear stresses along the dam/foundation interface. These results will then be used to evaluate the potential for separation (cracking) of the dam/foundation contact and the sliding stability of the dam along the abutment. 2.6 This subtask will interpret the results of the non-linear analyses and assess potential kinematically possible failure mechanisms that could produce a catastrophic failure of the dam resulting in the uncontrolled release of the reservoir. The evaluation will consider the amount, extent and duration of contraction joint opening,potential cracking of lift joints, shearing capacity of the contraction joints, sliding stability of the dam/foundation contact and the stress distribution within arch. Deliverable: A powerpoint presentation of the results of the Stage 2 FEA analyses. This presentation will describe the spectrum-matched acceleration time history record, the ANSYS finite element model of the dam and foundation,the results of the model verification process, static stress and deflection outputs and transient stresses and deflections for the dam and foundation for selected times during the earthquake. 3. Evaluate Right Abutment.Stability Purpose: An important component in the structural behavior of the arch is the stability of the rock blocks formed by the rock mass discontinuities in the right abutment. The discontinuities are the bedding and primary and secondaryjoint sets identified in the 2000 URS report with the inclusion of the spillway fault as discussed by DSOD in their July 2005 presentation. This task will evaluate the safety of the foundation due to loads acting from the dam on the rock blocks in the abutment. URS will develop a separate computer model of potential rock blocks using the computer software KBSlope. The results from the finite element analysis will be used to compute the forces on the rock blocks, and these will be applied to the model so that the sliding factor of safety can be estimated. The nonlinear arch analysis will be based on no rock block movement occurring. Exhibit A Therefore if the analyses indicate that displacement or sliding of the blocks is possible, stabilisation measures will be identified to prevent the movement. Deliverable: A powerpoint presentation of the results of the right abutment rock block stability analyses 4. DSOD Meeting/Workshop. Puri)ose: This task will cover preparation for and attendance at a second meeting with DSOD. This meeting present the Stage 2 analyses together with the evaluation of the analysis results. The purpose of this meeting is to demonstrate the methodology presented in the work plan with an actual analysis. The meeting would be an interactive workshop with the objective of obtaining a final consensus and agreement from DSOD on the methodology for the detailed nonlinear finite element analysis and,most importantly, on how the analysis results will be interpreted. Reaching this agreement at the meeting will be a critical step in the project,particularly considering that this will be the one of the first nonlinear arch dam analysis that DSOD will have used as a basis to accepted for a jurisdictional dam. Deliverable: Record of the workshop. STAGE 3 5. Incorporate workshop modifications. Incorporate modifications to the FEA model agreed to during the workshop and include any crack or deteriorated concrete noted during the site visit that might affect the response of the dam. Three earthquake records will be selected and the three components for each event will be amplitude modified to match, as closely as practical,.the target response spectra proposed by DSOD. 6. Detailed nonlinear analyses. Static,transient thermal and three nonlinear time history analyses will be run using the modified ANSYS FEA model. The results of the non-linear analyses will be evaluated using the agreed upon methodology and criteria for assessing whether potential kinematically possible failure mechanisms exist. The same basic steps run for Stage 2 will be run for the Stage 3 analyses using the ANSYS model modified as appropriate in Step 5. Three scaled natural time histories will be developed for these analyses. The amplitude of three earthquake records will be scaled so that their response spectra match the target spectra as closely as possible. The frequency content of the records will not be modified and as a consequence the spectra over some frequency ranges will exceed the target spectrum. Therefore,the arch's response to the three scaled natural earthquake records may fall over a range representing the upper and lower bound response to an MCE on the Rinconarda fault. The ground motion producing the median response will be compared with the response produced by the spectrum-matched earthquake from Stage 2,which could be considered the average response. Annual reservoir and ambient air temperature variations produce stresses in concrete dams. A transient thermal analysis will be run to predict the seasonal stress variations in the concrete due to 7 ej �3 f Exhibit A the fluctuations in reservoir and ambient air temperatures. The seasonal temperature induced stresses will be imported into the structural finite element model for use in the analyses. Annual ambient air temperatures will be based on available published data from the vicinity of the project site. The results and conclusions of the nonlinear analyses will be presented to the City before the final report is prepared. 7. Final Report The final report will fully document the assumptions for material properties, load and loading conditions, and safety criteria used in the analysis. The final analytical results will be presented graphically as well as discussion on the conclusions. A draft of the report will be submitted to City and the COE for review. After incorporating the comments from the City and COE, the intent is to submit the revised draft report to DSOD for their review and comment. DSOD comments will be addressed and the report will be finalized. Deliverable: Five hard copies and five CDs of the draft, revised draft and final reports. Analytical data not included in the report appendices can be provided on a CD if required. a. Project Management This task provides project coordination, supervision and support during the course of the work. This task will involve coordination of work between the City, DSOD, subconsultants and URS project personnel. This task will include keeping the City regularly briefed on the progress and results of the analyses. Monthly progress reports that accompany monthly invoices will include a summary of the work performed during the invoicing period, comparison of the actual work performed with the proposed work, actual man-hour summaries,work forecast schedule for the next month. Deliverable: Progress report to accompany monthly invoices. 8 Exhibit B CONTRACT PERFORMANCE TERMS 1. Business Tag. Contractor must have a valid City of San Luis Obispo business tax certificate prior to execution of the contract. Additional information regarding the City's business tax program may be obtained by calling(805) 781-7134. 2. Ability to Perform. Contractor warrants that it possesses, or has arranged through subcontracts, all capital and other equipment, labor, materials, and licenses necessary to cavy out and complete the work hereunder in compliance with any and all federal, state, county, city, and special district laws, ordinances, and regulations. 3. Laws to be Observed. Contractor shall keep itself fully informed of and shall observe and comply with all applicable state and federal laws and county and City of San Luis Obispo ordinances,regulations and adopted codes during its performance of the work. 4. Payment of Taxes. The contract prices shall include full compensation for all taxes that Contractor is required to pay. 5. Permits and Licenses. Contractor shall procure all permits and licenses, pay all charges and fees, and give all notices necessary. 6. Safety Provisions. Contractor shall conform to the rules and regulations pertaining to safety established by OSHA and the California Division of Industrial Safety. 7. Public and Employee Safety. Whenever Contractor's operations create a condition hazardous to the public or City employees, it shall, at its expense and without cost to the City, furnish, erect and maintain such fences, temporary railings,barricades, lights, signs and other devices and take such other protective measures as are necessary to prevent accidents or damage or injury to the public and employees. 8. Preservation of City Property. Contractor shall provide and install suitable safeguards, approved by the City, to protect City property from injury or damage. If City property is injured or damaged as a result of Contractor's operations, it shall be replaced or restored at Contractor's expense. The facilities shall be replaced or restored to a condition as good as when the Contractor began work. 9. Immigration Act of 1986. Contractor warrants on behalf of itself and all sub-contractors engaged for the performance of this work that only persons authorized to work in the United States pursuant to the Immigration Reform and Control Act of 1986 and other.applicable laws shall be employed in the performance of the work hereunder. 10. Contractor Non-Discrimination. In the performance of this work, Contractor agrees that it will not engage in, nor permit such sub-contractors as it may employ, to engage in discrimination in employment of persons because of age, race, color, sex, national origin or ancestry, sexual orientation, or religion of such persons. 11. Work Delays. Should Contractor be obstructed or delayed in the work required to be done hereunder by changes in the work or by any default, act, or omission of the City, or by strikes, fire, earthquake, or any other Act of God, or by the inability to obtain materials, equipment, or �3 -/S l Exhibit B:Contract Performance Terms Page B-2 labor due to federal government restrictions arising out of defense or war programs, then the time of completion may, at the City's sole option,be extended for such periods as may be agreed upon by the City and the Contractor. 12. Payment Terms. The City's payment terms are 30 days from the receipt of an original invoice and acceptance by the City of the services provided by Contractor(Net 30). 13. Inspection. Contractor shall furnish City with every reasonable opportunity for City to ascertain that the services of Contractor are being performed in accordance with the requirements and intentions of this contract. All work done and all materials fmiished, if any, shall be subject to the City's inspection and approval. The inspection of such work shall not relieve Contractor of any of its obligations to fulfill its contract requirements. 14. Audit. The City shall have the option of inspecting and/or auditing all records and other written materials used by,Contractor in preparing its invoices to City as a condition precedent to any payment to Contractor. 15. Interests of Contractor. Contractor covenants that it presently has no interest, and shall not acquire any interest direct or indirect or otherwise, which would conflict in any manner or degree with the performance of the work hereunder. Contractor further covenants that, in the performance of this work, no sub-contractor or person having such an interest shall be employed. Contractor certifies that no one who has or will have any financial interest in performing this work is an officer or employee of the City. It is hereby expressly agreed that, in the performance of the work hereunder, Contractor shall at all times be deemed an independent contractor and not an agent or employee of the City. 16. Hold Harmless and Indemnification. Contractor agrees to defend, indemnify, protect and hold the City and its agents, officers and employees harmless from and against any and all claims asserted or liability established for damages or injuries to any person or property, including injury to Contractor's employees, agents or officers which arise from or are connected with or are caused or claimed to be caused by the acts or omissions of Contractor, and its agents, officers or employees, in performing the work or services herein, and all expenses of investigating and defending against same,provided, however, that Contractor's duty to indemnify and hold harmless shall not include any claims or liability arising from the established sole negligence or willful misconduct of the City, its agents,officers or employees. 17. Year 2000 Compliance. The Contractor warrants that the goods or services provided to the City, including.those provided through subcontractors, are "Year 2000 compliant." For the purpose of this contract, "Year 2000 compliant" means that goods or services provided to the City will continue to fully function, fault-free, before, at and after the Year 2000, without interruption or human intervention; and if applicable, any data outside of the date range 1990- 1999, including leap years, will be correctly processed in any level of computer hardware or software, including, but not limited to,microcode, firmware, application programs, files and data bases. This warranty supersedes all warranty disclaimers or limitations, and all limitations on liability,otherwise provided by the Contractor. Upon request by the City,the Contractor will provide the City with a description of its Year 2000 compliance strategy, or statement of why this is not relevant to contract performance. Exhibit B:Contract Performance Terms Page B-3 18. Contract Assignment. Contractor "shall not assign, transfer, convey or otherwise dispose of the contract, or its right, title or interest, or its power to execute such a contract to any individual or business entity of any kind without the previous written consent of the City. 19. Termination. If, during the term of the contract, the City determines that Contractor is not faithfully abiding by any term or condition contained herein, the City may notify Contractor in writing of such defect or failure to perform; which notice must give Contractor a 10 (ten) calendar day notice of time thereafter in which to perform said work or cure the deficiency. If Contractor has not performed the work or cured the deficiency within the ten days specified in the notice, such shall constitute a breach of the contract and the City may terminate the contract immediately by written notice to Contractor to said effect. Thereafter, neither party shall have any further duties, obligations,responsibilities or rights under the contract. In said event, Contractor shall be entitled to the reasonable value of its services performed from the beginning date in which the breach occurs up to the day it received the City's Notice of Termination, minus any offset from such payment representing the City's damages from such breach. "Reasonable value" includes fees or charges for goods or services as of the last milestone or task satisfactorily delivered or completed by Contractor as may be set forth in the Agreement payment schedule; compensation for any other work, services or goods performed or provided by Contractor shall be based solely on the City's assessment of the value of the work-in- progress in completing the overall workscope. The City reserves the right to delay any such payment until completion or confirmed abandonment of the project, as may be determined in the City's sole discretion, so as to permit a full and complete accounting of costs. In no event; however, shall Contractor be entitled to receive in excess of the compensation quoted in its proposal. 20. Ownership of Materials. All original.drawings, plan documents and other materials prepared by or in possession of Contractor as part of the work or services under these specifications shall become the permanent property of the City,and shall be delivered to the City upon demand. 21. Release of Reports and Information. Any reports, information, data, or other material given to, prepared by or assembled by Contractor as part of the work or services under these specifications shall be the property of City, and shall not be made available to any individual or organization by Contractor without the prior written approval of the City. 22. Copies of Reports and Information. If the City requests additional copies of reports, drawings, specifications, or any other material in addition to what Contractor is required to furnish in limited quantities as part of the work or services under these specifications, Contractor shall provide such additional copies as are requested, and City shall compensate Contractor for the costs of duplicating of such copies at the Contractor's direct expense.. 23. Required Deliverable Products. Contractor will provide: ' a. Five (5) copies of the final report that addresses all elements of the workscope. Any documents or materials provided by Contractor will be reviewed by City.staff and,where necessary, Contractor will respond to staff comments and make such changes as deemed appropriate. Exhibit B:Contract Performance Terms Page B-4 b. One camera-ready original, unbound, each page printed on only one side, including any original graphics in place and scaled to size,ready,for reproduction. C. When computers have been used to produce materials submitted to the City as a part of the workscope, Contractor must provide the corresponding computer files to the City, compatible with the following programs whenever possible: • Word Processing Word • Spreadsheets Excel • Desktop Publishing Coreldraw,Pagemaker • Computer Aided Drafting(CAD) AutoCad Computer files must be on 31/2", high-density, write-protected diskettes, formatted for use on IBM-compatible systems. Each diskette must be clearly labeled and have a printed copy of the directory. 24. Attendance at Meetings and Hearings. As part of the workscope and included in the contract price is attendance by the Contractor at up to one public meeting before the City Council to present and discuss its findings and recommendations. Contractor shall attend as many "working" meetings with Division of Safety of Dams staff and City staff as necessary in performing workscope tasks. 25. Insurance. Contractor shall procure and maintain for the duration of the contract insurance against claims for injuries to persons or damages to property that may arise from or in connection with the performance of the work hereunder by Contractor, its agents,representatives,employees or sub-contractors. a. Minimum scope of insurance. Coverage shall be at least as broad as: • Insurance Services Office Commercial General Liability coverage (occurrence form CG 0001). • Insurance Services Office form number CA 0001 (Ed. 1/87) covering Automobile Liability, code 1 (any auto). • Workers' Compensation insurance as required by the State of California and Employer's Liability Insurance. • Errors and Omissions Liability insurance as appropriate to Contractor's profession. b. Minimum limits of insurance. Contractor shall maintain limits no less than: • General Liability: $1,000,000 per occurrence for bodily injury, personal injury and property damage. If Commercial General Liability or other form with a general aggregate limit is used, either the general aggregate limit shall apply separately to this project/location or the general aggregate limit shall be twice the required occurrence limit. • Automobile Liability; $1,000,000 per accident for bodily injury and property damage. • Employer's Liability: $1,000,000 per accident for bodily injury or disease. • Errors and Omissions Liability: $1,000,000 per occurrence. Exhibit B:Contract Performance Terms Page BS C. Deductibles and self-insured retentions. Any deductibles or self-insured retentions must be declared to and approved by the City. At the option of the City, either: the insurer shall reduce or eliminate such deductibles or self-insured retentions as respects the City, its officers, officials, employees and volunteers; or Contractor shall procure a bond guaranteeing payment of losses and related investigations, claim administration and defense expenses. d. Other insurance provisions. The general liability and automobile liability policies are to contain, or be endorsed to contain,the following provisions: • The City, its officers, officials, employees, agents and volunteers are to be covered as insureds as respects: liability arising out of activities performed by or on behalf of Contractor, products and completed operations of Contractor, premises owned, occupied or used by Contractor; or automobiles owned, leased, hired or borrowed by Contractor.. The coverage shall contain no special limitations on the scope of protection afforded to the City, its officers, official, employees,agents or volunteers. • For any claims related to this project, Contractor's insurance coverage shall be primary insurance as respects the City, its officers, officials, employees, agents and volunteers. Any insurance or self-insurance maintained by the City, its officers,officials, employees,agents or volunteers shall be excess of Contractor's insurance and shall not contribute with it. • Any failure to comply with reporting or other provisions of the policies including breaches of warranties shall not affect coverage provided to the City, its officers, officials, employees,agents or volunteers. • Contractor's insurance shall apply separately to each insured against whom claim is made or suit is brought, except with respect to the limits of the insurer's liability. • Each insurance policy required by this clause shall be endorsed to state that coverage shall not be suspended, voided, canceled by either party, reduced in coverage or in limits except after thirty (30) days' prior written notice by certified mail,return receipt requested,has been given to the City. e. Acceptability of insurers. Insurance is to be placed with insurers with a current A.M. Best's rating of no less than A:VII. f. Verification of coverage. Contractor shall furnish the City with a certificate of insurance showing maintenance of the required insurance coverage. Original endorsements effecting general liability and automobile liability coverage required by this clause must also be provided. The endorsements are to be signed by a person authorized by that insurer to bind coverage on its behalf. All endorsements are to be received and approved by the City before work commences.