Proposed Building Alteration – Vallejo Deaf Church

Project Details

This project involves the structural analysis and engineering design for building alterations at the Vallejo Deaf Church, specifically addressing the repair and modification of existing partially grouted CMU walls. The scope includes the replacement and installation of masonry lintel beams to facilitate the expansion of existing openings into larger door systems, including 5-foot and 6-foot double doors. The engineered solution utilizes fully grouted 8″ CMU lintels reinforced with #4 and #5 steel bars, designed to integrate seamlessly with the existing masonry structure. The engineering process included a comprehensive loading analysis to ensure compliance with the 2022 California Building Code (CBC), IBC 2021, and ASCE 7-16 standards. Analysis determined that seismic loads govern the structural design in both directions. The building is situated in Seismic Design Category D, with a mapped spectral response acceleration (Ss) of 1.862 and a design spectral acceleration (SDS) of 1.490. The structure was also evaluated for a basic wind speed of 92 MPH under Exposure Category C. The foundation system utilizes the existing reinforced concrete wall footings, verified for adequacy under an allowable soil bearing pressure of 1,500 psf. To ensure safety during construction, the project requires a detailed temporary shoring plan and a strictly defined demolition sequence to support the roof and masonry loads while load-bearing elements are replaced.

Role

Structural Engineer/Designer

Services Provided

The scope of services included the preparation of structural calculations and structural drawings for the proposed modification of door openings in an existing concrete masonry unit (CMU) system. Structural calculations included the analysis and design required to widen two existing 36-inch exterior door openings in the CMU wall. This included the design of appropriate lintels, which may have consisted of structural steel members or reinforced CMU bond beams, along with required jamb reinforcing, bearing lengths, and anchorage. The work also included the structural analysis and design necessary to convert one existing 30-inch interior door opening into a 60-inch double door, including the design of a new header, jamb framing, and verification of the load path to ensure that gravity and lateral loads were adequately transferred through the modified structure. Additional analysis included both out-of-plane and in-plane checks of the affected CMU wall segments for wind and seismic loads, including verification of shear transfer across modified wall piers and the design of collectors or reinforcing as required. The scope further included the design of epoxy post-installed anchors with appropriate edge distance and spacing checks, ensuring compatibility with the existing grout and reinforcing bar layout. Temporary shoring considerations and notes were also provided to address construction sequencing and maintain structural stability during the removal and replacement of existing headers. Structural drawings included the plans, elevations, and details necessary to clearly communicate the retrofit work for permitting and construction. The drawing set included demolition and protection notes at each modified opening, identifying existing conditions, required removals, and construction phasing. CMU wall opening retrofit elevations were provided for each location, showing clear opening widths and heights, required bearing lengths, reinforcing layouts, and any required embed plates or steel angles. Lintel and header details were included for the selected systems, which may have consisted of steel wide-flange or tube sections, steel angles, or reinforced CMU bond beams, including bearing pads and load transfer requirements to the supporting wall or foundation. The drawings also provided jamb reinforcing and doweling details, grout and lap schedules, and shear transfer details across modified or cut masonry cells. For the interior partition door conversion, framing plans or elevations illustrated the new double-door configuration, including headers, king and jack studs, cripple studs, and connection requirements. The drawing package was supplemented with general structural notes, design criteria, material specifications, and post-installed anchor schedules necessary to clearly define the construction requirements and ensure compliance with applicable codes and standards.