Loading...
HomeMy WebLinkAbout1997-12-15 City Council (26)21 City of Palo Alto City Manager’s Report HONORABLE CITY COUNCIL FROM: AGENDA DATE: CITY MANAGER DECEMBER 15, 1997 DEPARTMENT: PUBLIC WORKS CMR:491:97 SUBJECT:REQUEST FOR APPROVAL OF CONSULTANT CONTRACT AMENDMENT FOR DESIGN OF TEMPORARY SEISMIC BRACING FOR THE MUNICIPAL SERVICE CENTER RECOMMENDATIONS Staff recommends that Council: Direct staff to develop a Capital Improvement Project to construct temporary seismic bracing at the Municipal Service Center (MSC) Buildings A, B, and C at an estimated cost of $1 million and return to Council with a recommendation for an award of contract and Budget Amendment Ordinance to construct those improvements. Approve an amendment (Attachment D) to an existing short-form agreement with Dames & Moore for consultant services in the amount of $50,000. The amendment will provide for the preparation of filial construction documents for temporary seismic bracing of MSC Buildings A, B and C, and for construction administration services. Direct staff to review and develop a plan to address the long term issues associated with the future utilization of the MSC buildings, including permanent seismic retrofitting and related issues. BACKGROUND In 1986, City Council passed Ordinance No. 3666 establishing requirements for a seismic hazard identification program. The three categories of buildings included, under this Ordinance are: unreinforced masonry buildings; all pre-1935 buildings other than unreinforced masonry that have 100 or more occupants; and all buildings, with 300 occupants or more constructed between January 1, 1935 and August 1976. MSC Buildings CMR: 491:97 Page 1 of 5 A, B and C did not fall into any of the categories for which reporting was required, so no further steps were taken relative to the identification of seismic hazards. In 1997, Dames & Moore was hired to prepare a seismic study of Buildings A, B and C as part of Capital Improvement Program (CIP) Project 18508 (Public Buildings Structural Improvements), (refer to CMR 197:97). The study was undertaken because concrete tilt- up buildings like those at the MSC suffered extensive damage in every significant earthquake since 1971. These types of buildings have been shown to be more susceptible to extensive damage and collapse than buildings constructed with other techniques. DISCUSSION Seismic Study MSC Buildings A, B and C (refer to site map, Attachment A) were constructed in 1965 and were designed to meet the standards of the 1961 Uniform Building Code (UBC). The Seismic Upgrade Study by Dames & Moore (July 28, 1997) identified Buildings A, B, and C as needing significant work in order to meet current seismic codes. Facilities constructed under the current UBC require twice the level of seismic loading as exists in the MSC buildings. The buildings pose a potential life-safety hazard because they are prone to a significant degree of failure and collapse when subjected to a significant seismic event. According to the Working Group on California Earthquake Probabilities (of the United States Geological Survey), there is a 5 percent chance of a magnitude 7.0 earthquake on the San Francisco Peninsula segment of the San Andreas Fault in the next five years. There is a similar probability of a similar seismic event on the Hayward fault in the same time frame. Since these faults are relatively independent of each other, the probability of a significant seismic event affecting the MSC is approximately 10 percent in the next five years. It is clear that the occurrence of a magnitude 7.0 or greater event on either fault would have the potential to cause significant damage to the MSC buildings A, B, and C. Interim Measures - Results of Temporary Seismic Bracing Study Based on the information in the July 1997 Seismic Upgrade Study, Public Works immediately proceeded with an additional investigation of the feasibility and cost of temporary bracing to lower the risk of collapse until further studies on seismic retrofit and space utilization options can be made. Shoring the building will reduce the risk of collapse, but cannot be considered a long-term substitute for a seismic upgrade of all three buildings. The temporary bracing will not allow for continued functional use of the buildings after a major seismic event. CMR: 491:97 Page 2 of 5 A report on the feasibility, preliminary design and cost of temporary bracing was completed by Dames & Moore on October 17, 1997. The temporary bracing report recommends temporary bracing that would consist of large steel buttresses located around the perimeter of each of the three buildings, as shown on attachments B & C. The estimated cost to brace Buildings A, B and C is approximately $950,000, which includes final design, construction administration services, contingency, testing, inspection, and other related tasks. Some vehicle parking spaces will be eliminated by the bracing and equipment and materials currently stored at proposed temporary bracing locations outside the building would need to be moved. No employees would need to be relocated during the construction. Next Steps In order to permanently retrofit the buildings to meet current seismic standards, the Seismic Upgrade Study recommends making the roof structural system continuous, adding concrete shear walls and adding a new, stiffer steel skeleton inside the shell of the buildings. A preliminary cost analysis indicates that the cost of permanently retrofitting the three existing buildings may be comparable to constructing new replacement buildings. Given the number and complexity of the issues involved in a seismic retrofit of this scale, it is recommended that staff first identify the issues that should be considered and return to Council with a plan for study of the future utilization of the MSC buildingsl Issues to be considered in the long range study of the future of the MSC buildings will include but not be limited to the nature and cost of permanent seismic retrofitting, associated improvements for ADA requirements, upcoming building maintenance (Infrastructure Management Program) needs, FEMA floodplain requirements related to the buildings’ location and ground floor elevations, and the overall cost-effectiveness of .meeting these multiple requirements by means of retrofitting the existing buildings as opposed to constructing new ones. Additionally, given the scope and magnitude of the issues, a review of future programmatic needs and space requirements for the users and operations at the MSC should be included in the discussion of future options. Given these issues, staff intends to propose a new CIP project for FY 1998/99 to initiate a study of the future of MSC buildings A, B, and C. The study itself will take one to two years to complete, and any recommended improvements would take an additional two to three years to complete. Thus, the temporary seismic bracing recommended in this report will have a life expectancy of at least three to five years. Staff believes that duration is significant enough to justify the expenditure of funds for the bracing in the meanwhile. Staff Approval The bracing recommended by this report will require review and approval consistent with the requirements of the ARB ordinance. That review will be conducted as a staff level CMR: 491:97 Page 3 of 5 process because the work is temporary in nature and will be removed when permanent seismic improvements are constructed in the future. POLICY IMPLICATIONS This report does not represent changes to existing City policy. The recommendations are consistent with existing policy direction regarding the seismic retrofitting of existing City buildings. TIMELINE If Council approves the recommended actions, final design of the temporary bracing could be completed in one to two months. Construction of the temporary bracing could begin shortly afterwards and would take up to six additional months to complete (including bidding time). If Council directs staff to proceed, the project could be completed during Summer 1998. RESOURCE IMPACT The fee for services that would be covered under the amendment is estimated to be $50,000. Public Buildings Structural Improvements, CIP 18508, has sufficient funds for this work. When a CIP is established and a Budget Amendment Ordinance (BAO) is adopted for the construction portion of the project, the design fees would be reimbursed to CIP 18508. The estimated cost of the bracing construction is $950,000, which would be funded through a combination of General Fund and Enterprise Fund reserves based on the proportional use of the facilities which is roughly 50/50. Staff will return to Council with a BAO after the bids for the work are received. That action will contain a precise calculation of the shares between the Enterprise and General Funds. ENVIRONMENTAL ASSESSMENT The temporary bracing is categorically exempt under the California Environmental Quality Act. ATTACHMENTS Attachment A: Attachment B: Attachment C: Attachment D: Site map Temporary seismic bracing mock-up, Building A Temporary seismic bracing mock-up, Building C Consultant contract amendment PREPARED BY: Karen Bengard, Senior Engineer, Public Works CMR: 491:97 Page 4 of 5 CMR: 491:97 Page 5 of 5 ATTACHMENT A ATTACHMENT B Temporary braces at west elevation of Building A, Type B1-A. Note that right side of stairway will be blocked temporarily due to braces. ATTACHMENT D AMENDMENT NO. ONE TO CONTRACT NO. C7094743 BETWEEN THE CITY OF PALO ALTO ALTO DAMES & MOORE This Amendment No.One to Contract No. C7094743 ("Contract") is entered into by and between the CITY OF PALO ALTO, a chartered city and a municipal corporation of the State of California ("CITY"), and DAMES & MOORE, a Delaware corporation, located at 221 Main Street, Suite 600, San Francisco, CA 94105-1917 ("CONSULTANT"). , RECITALS- WHEREAS, the Contract was entered into between the parties for the provision of shoring and construction design services. WHEREAS, the parties wish to amend the Contract;’ NOW, THEREFORE, in consideration of the covenants, terms, conditions, and provisions of this Amendment, the parties agree: SECTION I. The following exhibit to the Contract is hereby amended, in whole or in part, to read as set forth in the attachment to this Amendment, which are incorporated in full by this reference: a. Exhibit "A" entitled "Scope of work". SECTION 2. Except as herein modified, all other provisions of the Contract, including any exhibits and subsequent amendments thereto, shall remain in full force and effect. // // // // // // // 971208 s~n 0071329 IN WITNESS WHEREOF, the parties have by their duly authorized representatives executed this Amendment on the date first above written. ATTEST:CITY OF PALO ALTO City Clerk Mayor APPROVED AS TO FORM:DAMES & MOORE Senior Asst. City Attorney By: Its: APPROVED:Taxpayer I.D. No. 00-7965189 Assistant City Manager Director of Public Works Acting Director of Administrative Services Risk Manager Attachment: EXHIBIT "A": SCOPE OF WORK~ " 97 I~0~ s~yn 0071329 Scope of Work This Scope of Work details the design and construction administration services required to complete the temporary bracing preliminary designs shown in the "Phase I: Temporary Bracing Report for the Municipal Service Center," dated October 16, 1997: Schematic Design Phase (024) ¯ Attend up to four (4) meetings with MSC employees to discuss issues related to the installation of the temporary bracing. Construction Documents Phase (026) ¯ Provide construction documents for the installation of temporary bracing as shown in the Temporary Bracing Report, except as noted by the City of Palo Alto fax dated October 23, 1997. Construction documents are due to the City of Palo Alto, Public Works Engineering, by January 30, 1998. Design Consultant Phase (022) ¯ Provide professional servicesthrough the construction award. This includes, but is not limited to, a. providing the names of at least three construction firms that would be capable of fabricating and installing the temporary bracing, b. answering questions of the prospective contractors, c.assisting with an evaluation of the quality of the bids received from the prospective contractors. Reimbursables (027) Reimbursable expenses include actual expenditures made in the interest of the project such as reproduction costs, travel and postage. Additional Services A (028) Investigate solutions to conflict between a proposed footing and the underground tanks on the south side of Building B between lines 6 and 8. Options include moving the brace or designing a footing to straddle the tanks instead of removing them. Operational criteria must be taken into account in the design. Construction Consultant Phase (032) [] Provide construction administrative services during the construction phase of the temporary bracing effort. Consti-uction administrative services shall include, but not be limited to, a.reviewing shop drawings, b.responding to Contractor’s questions, c.making periodic site visits, d.attending monthly construction meetings. Payment shall be on a time and materials basis, not to exceed an aggregate total of $50,000. Costs for each phase shall be listed according to the phase numbers given in parentheses above. Scope of Work This Scope of Work details the design and construction administration services required to complete the temporary bracing preliminary designs shown in the "Phase I: Temporary Bracing Report for the Municipal Service Center," dated October 16, 1997: Schematic Design Phase (024) Attend up to four (4) meetings with MSC employees to discuss issues related to the installation of the temporary bracing. Construction Documents Phase (026) [] Provide construction documents for the installation of temporary bracing as shown in the Temporary Bracing Report, except as noted by the City of Palo Alto fax dated October 23, 1997. Construction documents are due to the City of Palo Alto, Public Works Engineering, by January 30, 1998. Design Consultant Phase (022) [] Provide professional services through the construction award. This includes, but is not limited to, 1. providing the names of at least three construction firms that would be capable of fabricating and installing the temporary bracing, 2.answering questions of the prospective contractors, 3.assisting with an evaluation of the quality of the bids receiTed from the prospective contractors. Reimbursables (027) Reimbursable expenses include actual expenditures made in the interest of the project such as reproduction costs, travel and postage. Additional Services A (028) [] Investigate solutions to conflict between a proposed footing and the underground tanks on the south side of Building B between lines 6 and 8. Options include moving the brace or designing a footing to straddle the tanks instead of removing them. Operational criteria must be taken into account in the design. Construction Consultant Phase (032) Provide construction administrative services during the construction phase of the temporary bracing effort, Construction administrative services shall include, but not be limited to, 1.reviewing shop drawings, 2.responding to Contractor’s questions, 3.making periodic site visits, 4.attending monthly construction meetings. Payment shall be on a time and materials basis, not to exceed an aggregate total of $50,000. Costs for each phase shall be listed according to the phase numbers given in parentheses above.