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Home My WebLink AboutAgenda Report - December 21, 2022 C-04CITY OF 100 10 zt� mss+ C A L I FORN IA AGENDA ITEM C•4 COUNCIL COMMUNICATION AGENDA TITLE: Approve Plans and Specifications and Authorize Advertisement for Bids for Lodi Station Parking Garage Repair Project MEETING DATE: December 21, 2022 PREPARED BY: Public Works Director RECOMMENDED ACTION Approve plans and specifications and authorize advertisement for bids for Lodi Station Parking Garage Repair Project. BACKGROUND INFORMATION: The Lodi Station Parking Garage, located at 50 North Sacramento Street, was constructed in 2002, using post -tensioned concrete. In June of 2022, a vehicle hit the concrete wall barrier on the third floor of the parking structure and cause extensive damage to the barrier and the concrete floor. Staff hired Walker Consultants, of San Francisco to conduct a structural assessment of the extent of the damage. Walker Consultants is the original structural designer of the parking structure and has extensive post -tension structure experience. The assessment report indicated the damage does not cause any structural issues to the parking structure but recommended the area remain fenced off until repairs are complete (Exhibit A). This project includes the replacement of the damaged concrete barrier, reset the post -tension steel cable; and other incidental and related work as shown on the plans and specifications of the project. The plans and specifications are on file in the Public Works Department. The planned bid opening date is February 1, 2021. The project estimate is $125,000. Staff recommends Council approve plans and specifications and authorize advertisement for bids for Lodi Station Parking Garage Repair Project. FISCAL IMPACT: The repair is necessary to repair the vehicle damage to the existing structure and to avoid additional, future damage if the repairs are not addressed. This project does not impact the General Fund. FUNDING AVAILABLE: To be identified with the project award a -Jac Charles E. Swimley, Jr Public Works Director Prepared by Lyman Chang, City Engineer/Deputy Public Works Director CES/LC/cd Attachment cc: Public Works Management Analyst Facilities Superintendent Transportation Manager APPROVED: IJV XWqbJ Stephen Schwabauer, City Manager \\cvcfilv02\pubwks$MP\PROJECTS\TRANSIT\Lodi Station Parking Structure\2022 Structural Repair\CPSA doc 12/5/2022 WALKER CONSULTANTS October 11, 2022 Mr. Lyman Chang City Engineer/Deputy Public Works Director City of Lodi 221 W. Pine Street Lodi, CA 95240 Re: Structural Investigation and Repair for Lodi Station Parking Structure 50 N. Sacramento Street, Lodi, CA Dear Mr. Chang, 135 Main Street, Suite 1030 San Francisco, CA 94105 Office: 415.644.0630 Fax: 415.644.0637 www.walkerparking.com Walker Parking Consultants is pleased to submit for your review this letter report for the Structural Investigation/Repair of damaged concrete barrier wall at the Lodi Station Parking Structure. Background and Description The Lodi Station Parking Structure is a 3 -level post -tensioned concrete parking structure. The lateral system for the parking structure consists of special reinforced concrete shear walls. At the perimeter of the building concrete crash barrier walls are provided to prevent cars from accidentally falling off the edge of the garage. Metal screens were provided for aesthetics reason. One of the concrete barrier walls on the north side was hit by a car causing severe damage to the wall. The City of Lodi desires to restore the concrete barrier wall. DISCUSSION The following documents were provided to Walker Parking Consultants in order to assess the extent of the damage and feasibility of repairing and restoring the concrete barrier. Record drawings for Lodi Station Parking Structure prepared by Gordon H. Chong and Partners June 29, 2000. Walker Consultants was the structural engineer for the project. Based on the drawing date, the project was designed to the California Building Code 1998 Edition. CBC 1998 required the barrier walls to be designed for a load of 6000 lbs acting at a height of 18 inches above the floor. The current edition of the California Building Code, CBC 2019, requires the wall to be designed for 6000 lbs but acting at 18" or 27", non -currently, above the floor. WALKER CONSULTANTS OBSERVATIONS and FINDINGS Edward Y.C. Tan visited the site on August 24, 2022, to assess the damage on the barrier wall. The following observations were made: The damaged concrete barrier wall is on the third level, east side of the garage. The barrier wall suffered extensive damage (see Photo 1). The barrier wall was hit with a force that caused the wall to shear off from the edge of the slab (see Photo 2). The Code required barrier load is based on a car travelling at 5 MPH. The car that hit the wall was going at a speed far greater than the Code assumed speed. The hooks for the wall vertical bars were pulled out. These caused spalling of the concrete cover on the inside face of the wall (see Photo 3). In some areas, the concrete at the base of wall fell off. The main slab post -tensioning cables were exposed due to spalling of the concrete cover but were not damaged (see Photo 4). The anchors for the temperature cables running perpendicular to slab edge were exposed in two areas, at the middle of the slab edge and close to the east edge (see Photo 5). The concrete at the anchors spalled causing the anchors to move. These anchors will need to be re -seated. The barrier wall has been displaced from its original location. There are a few of the vertical bars still attached to the concrete slab. The wall is leaning out and has pushed the metal screen. The metal screen is slightly bowed and pushed out (see Photo 6). CODE REQUIREMENTS The parking structure was designed and built in 2000. CBC 1998, the governing code at that time, required the barrier walls to be designed for a load of 6000 lbs. The current Code, CBC 2022 requires the same load but needs to be checked for two conditions. The load acting at 18" above the floor and at 27" above the floor. The replacement wall will be designed to these loading conditions. In new construction, the barrier wall vertical bars will be anchored into the concrete slab. Since the slab is existing, the vertical bars will be doweled into the concrete slab by drilling into the slab and anchoring the vertical bars with epoxy. Since the slab edge has had damaged, and new holes need to be dilled for the wall vertical bars, it would be prudent to provide a redundancy to the wall's structural strength. It is recommended that the wall, also be designed to resist the barrier load, spanning horizontally between columns. Added horizontal reinforcement be provided, to resist the load and the walls be provided with clip angles at the ends. WALKER CONSULTANTS Conclusion Based on our observation the damage cause by the collision is limited to the barrier wall and the slab edge supporting it. The structural integrity of the concrete deck and the remaining portion of the existing parking structures has not been compromised. The repair work would be limited to the affected area only. We hope that this has addressed your concern. If you have any questions or need further clarification, please give us a call and we will gladly have a discussion with you. Very truly yours, WALKER CONSULTANTS onu Y � 4� 0A t'A S 4666 * 06.30.23 \ OF CALl�� WALKER CONSULTANTS Photo 1 — Damage to wall F;,no►" By L pRp. 1379 1 .FG91 r Photo 2 — Wall sheared off from slab edge WALKER CONSULTANTS F gyDIIJ L ORD. 1379 1' .EC 91 Photo 3 — Spalling of concrete cover WALKER CONSULTANTS Photo 4 — Exposed main slab PT cables Photo 5 — Temperature cable anchors WALKER CONSULTANTS Photo 6 — Bowed metal screen