CITY COUNCIL REGULAR MEETING AGENDA PACKET

4 | Page City of Pleasanton Amador Theater programmatic Rehab vs. Build cost comparison 2018-024-02 As noted above the construction of the original building pre-dates the 1933 Field Act. While the building appears to have performed well since it was constructed, it is anticipated that it will require significant structural modifications to make it comply with current building code requirements. For example, ties within the pilasters may not conform to current standards requiring seismic hooks and the spacing may be more than allowed by current code. Due to the seating capacity of the theater, 600±, the code would require the structure to comply with the requirements of a Risk Category III building (CBC Table 1604A.5). Recommendations for the evaluation of existing building is provided by DSA Interpretive Regulation (IR) EB- 3, “Evaluation and Design Criteria Report” (EDCR). The current edition of this IR was issued on May 4, 2021 and is subject to renewal on an annual basis. This document further defines items that must be completed as part of the preparation of a compete EDCR before structural calculations and a structural retrofit can begin. The following items are identified: • Material Testing Program – this program shall be developed to identify the nature of the materials used in the existing construction. There are specific requirements to be met where full plans are available of the existing construction, or partial or no plans are available. Specific criteria are specified within ASCE 41, which is specified by the IR. • Condition Assessment – a detailed condition assessment is required, which may require destructive investigations to the existing structure in order to fully assess the condition of all structural elements within the structure. This level of assessment is beyond the limited visual observations used for this structural assessment. • Geotechnical and Site Hazards – as part of the EDCR submittal, a site specific Geohazards Report is required. ASCE 41 specifies minimum data collection requirements within Chapter 6, which are further refined in Chapters 9 through 12 of the document as follows: • Chapter 9 – Structural Steel: where original construction documents are inconclusive or do not exist that define the materials that were used, but the date of construction is known, a minimum of 3 strength coupons and 3 bolt and rivets shall be randomly removed from each component type for testing. For the theater proper, drawings do not exist, so this section would apply to the evaluation of the steel, riveted roof trusses and any steel elements in the balcony framing. Structural drawings for the Lobby and Scene Shop are available, so not steel tests are anticipated for these two structures. For the theater, it is anticipated that a total of 6 steel coupons and 6 rivets will require testing, 3 each from the roof framing and 3 each from the balcony framing. • Chapter 10 – Concrete: for concrete elements where the design strength is not known, a minimum of six core tests per every 400 cy of concrete or 10,000 sf of surface area, whichever requires more shall be made. If tests indicate that more than one class of concrete was used in the construction, additional tests will be required. Due to the age of the theater, it is anticipated at this time that one class of concrete was most likely used. The volume of concrete for the theater is estimated at 357 cy resulting in a minimum of 6 cores required for testing and the square footage of the concrete walls is estimated at 11,000 sf resulting in 12 cores required based on the surface area. The minimum number of core samples to be taken is, therefore, controlled by the surface area of the concrete and is 12 samples. The superstructure of the lobby and scene shop buildings is wood frame construction. The available drawings do indicate the concrete strength that was used, so additional concrete tests for these structures are not anticipated. In addition to the core samples, samples of the existing wall and column reinforcing will need to be taken so that the grade of the reinforcing can be determined and the type of reinforcing use (square, twisted, deformed, other) can be confirmed. In addition to these Page 60 of 454