Tell us a bit about the project.
Lim Sam Adiputra (LSA): It’s eye-catching, inside and out. The post-tensioned (PT) concrete structure features an oversized cantilever and a skybridge connection to the existing Biology Building. It supports interdisciplinary science studies in a variety of lab applications with collaborative learning areas throughout. It’s a gorgeous building with a notable presence on campus, and from our standpoint, there were a lot of unique conditions we navigated to make it a success.
Corey Johnson (CAJ): The project’s civil scope generated additional parking and improved access routes. The building bookends the science hub community and establishes a prominent gateway leading to the northern heart of campus. Improvements included construction of an adjacent parking lot with EVC stalls, bioretention for water treatment, a service loading area, utility extensions, and connection to and expansion of the existing steam utility tunnel. What you can’t see is everything that went on underground!
What made this project different? Were there constraints and how were they addressed?
LSA: The underground conditions. There is solid bedrock on the eastern portion of the site that quickly dips to poor soil conditions to the west. Essentially, we were building on the side of an underground mountain surrounded by peat (a ton of it!). The technical challenge: how do we design a structure to safely sit on two extremely different soil types? To address this, we implemented a system of micropiles on one end and secured foundations directly to bedrock at the other.
CAJ: The site also straddles two separate drainage basins: The north basin drains to Bellingham Bay while the south basin drains to a wetland. We worked closely with the City of Bellingham to develop a strategy to mitigate stormwater discharge given these varying basin requirements. We carefully calculated the northern basin existing trunk line’s capacity so that it would not be exceeded with the addition of the ISB development; in the southern basin we were very deliberate on how we graded the project site to match existing conditions and stay below discharge thresholds.
What are your favorite features?
CAJ: The bioretention system and the stormwater habitat (designed in coordination with the landscape architect, Berger Partnership) are really special. Two bioretention cells provide water quality treatment for the building’s loading dock and new parking lot. A sustainable stormwater habitat captures all runoff from the roof. Strategically placing these two systems adjacent to one another created a unique, tiered pond that enhances the on-site experience and contributed toward LEED Gold certification.
The benches that sit outside the building are made from the cedar trees that grew where the ISB now sits. The raingardens use mulch from the same trees to foster new saplings and trunks were repurposed to support habitat restoration efforts in nearby Terrell Creek. Read more from Sophia Reynolds, a junior at Western majoring in environmental education.
Are there standout structural aspects?
LSA: The building shape shifts dramatically between the ground level and upper floors, and forms a large cantilevered element at the east end. It’s a beautiful and defining space. Post tensioned concrete beams extend to support the long overhang while keeping the structural depth and architectural form minimal. A hidden steel column ties all three of the cantilevers together so that if one level deflects, it shares the load with the others. Feature stairs are backdropped by a scored, exposed concrete wall and surrounded by polished concrete slab floors.
We also had to consider the new connection to the Biology Building, including elevation differences between the structures and phasing while the building was occupied. We joined the structures with a skybridge, engineering a sliding connection that enables the structures to move independently from one another.
Are there unique design considerations for a lab building? How did you address them?
LSA: Lab buildings require special attention to floor vibrations, and this project required tight vibration limits for the research spaces. To meet these requirements we utilized a PT concrete slab, which saved cost and allowed for shallow structure. However, the challenge with PT slabs is that they can limit future flexibility for reprogramming of spaces. To overcome that limitation, we strategically identified locations that are zoned for future floor penetrations, and provided sufficient clearance to cables in the lab spaces for anchoring equipment.
What was the biggest challenge the team faced?
LSA: Developing a seismic design for the variable soil conditions was our biggest technical challenge. The foundation design, specifically at the west end where the micropiles are located, required a lot of early analysis and performance studies. We worked closely with the geotechnical engineer and pile subcontractor to understand exactly how seismic loads would be transferred from the top of the building to the foundation.
CAJ: Another big challenge (and I think the entire project team would agree!) was tying in a new steam tunnel to the existing tunnel. Just about every consultant had a critical role to play in the design. There was a ton of coordination that took place to get everything dialed in.
Are there any examples of issues the team identified early that helped the design process?
LSA: Because we knew soil conditions were going to be an initial hurdle, we worked closely with GeoEngineers and BNBuilders early on to fully understand the bedrock topography below the building. BNBuilders used ground penetrating radar to 3D map the underlying bedrock, which we then imported into our Revit model. This information was crucial to making major decisions for the building design, including the location and size of the basement, where key seismic systems should be located, and where pile systems would be implemented.
CAJ: We were able to simplify the storm design during construction after uncovering an existing system that we were able to tie into. This significantly reduced the amount of new storm pipe that was installed (93 feet to be precise!).
What was one thing you learned during this process?
CAJ: There are sometimes unforeseen limitations (or in some cases, convenient advantages!) discovered during construction. These are the moments when a truly creative and collaborative team become key to a project’s success.
LSA: This was the first project I led CA on. Ask a lot of questions. It’s better to ask and be informed. It helped me to be more confident in what I am doing as an engineer. It’s important to be firm, but also be a team player. Thanks to the site, I also learned a lot about micropile modeling and analysis!
Why did you like working on this project?
CAJ: I have family who attended WWU (go Viks!) so the ISB is definitely a standout. It was exciting being able to discuss the building with them and other recent projects on Western’s campus (check out Alma Clark Glass Hall, Multicultural Center and Kaiser Borsari Hall.)
I liked working with _______ because…
CAJ: Janice Young from Perkins&Will who kept the wheels turning. And hats off to BNBuilders. The construction crew endured record heat, excessive snowfall, and a pandemic all within the same year! I especially enjoyed working with Ephram with BNB who swiftly helped coordinate challenges during CA.
LSA: I would agree: kudos to Janice. She coordinates and does so many different things. She was the main contact person for CA. Very responsive, and humble too! And thanks to Marsha Swatosh and Ben Barlow in our office who spent significant time mentoring me.
The ISB just opened in spring quarter of 2022!
Project Team: Owner: Western Washington University / Architect: Perkins&Will / Civil & Structural Engineer: Coughlin Porter Lundeen / General Contractor: BNBuilders / Landscape Architect: Berger Partnership / Geotechnical Engineer: GeoEngineers / Mechanical & Electrical Engineer: Affiliated Engineers NW / Lighting Design: Blanca Lighting Design / Acoustic Consultant: Greenbusch Group / AV Consultant: The Sextant Group/NV5
Images courtesy: Perkins&Will, BNBuilders and Max Widjaja