San Jacinto College Central Campus: New Classroom Building
A College’s Dedication to a Resurging Material Fuels an Appetite for More Sustainable Buildings
The San Jacinto Community College Central Campus Classroom Building fell late in a developmental timeline that was burdened with rising construction costs and interrupted by Hurricane Harvey. Schedule pressures concurrent with the cost of lumber trending down as steel prices spiked upward prompted the college to consider an unconventional material.
By 2019, the college committed to mass timber for their 120,000-sf classroom building and Walter P Moore was chosen as Structural Engineer of Record. To meet the strict opening deadline of fall semester 2021, design and construction would comingle while mass timber construction needed to be quickly embraced by everyone involved. Working under a tight schedule with a novel building material necessitated creative thinking and efficient communication.
Early drawing packages were required to allow a general contractor to be competitively selected during design. Walter P Moore participated in the partner selection process while also working on structural design. Clearing these hurdles launched the firm into the next phase of work. This included finishing the structural design while simultaneously coordinating the integration of systems and structure with the mass timber fabricator and MEP subcontractors. All the while, Walter P Moore faced a unique challenge with the building’s foundation system.
- Mass Timber
- Reuse of Existing Buildings
The new classroom building is located on the site of two previous concrete buildings. The college requested that the existing foundations be reused as much as possible. Because architecture has evolved since the previous buildings were built, the new floor plan and column layout could not fit the original footprint.
An extensive analysis of the existing piers indicated which could be reused and where new piers were required. New grade beams tied the old and new systems together. As unforeseen conditions were discovered during the demolition of the previous buildings and clearance of the site, Walter P Moore’s Diagnostics team mobilized to assess the true condition of foundation elements identified for reuse. The team developed a grading system determining which elements were approved, in need of repair, or unusable for the contractor. Timely action and constant communication during this unconventional process kept the project on schedule and maximized the existing foundation reuse.
The biggest structural challenges associated with mass timber involved the wind force resisting system and connection detailing. To optimize cost and flexibility, Walter P Moore proposed two schemes for wind force resisting systems: cross-laminated timber (CLT) shear walls and steel brace frames. After reviewing both options with the design and construction teams, steel brace frames were chosen.
Once the mass timber supplier was on board, Walter P Moore began talking through options for the unique appearance of connection details. Mass timber is less standardized than steel or concrete, so the design team had to make informed proposals to the fabricator, balancing creativity with flexibility, to arrive at the details of structural connections. Details of how the building’s brick facade would be supported by mass timber received particular attention.
Additionally, the CLT roof of the building was covered in 30,000 square feet of photovoltaics to help power the building. Walter P Moore worked with the provider to coordinate and detail the roof attachment for the solar panels.
Walter P Moore leapt into action with their partners on this innovative building, which was the largest mass timber classroom building in the U.S. at the time of design. Not only did mass timber solve problems of cost and schedule, but it also represents San Jacinto Community College’s commitment to the future.
EXTERNAL PROJECT TEAM
Owner: San Jacinto College
Architect: Kirksey Architecture
Structural Engineer: Walter P Moore
Contractor: Tellepsen Corporation
Landscape Designer: Kudela & Weinheimer
MEP Engineer: JonesDBR
CLT Supplier: Nordic Structures