Structural Shoring for UCSF Campus Expansion

Joe Lazzaretti
Oct 10
9 min read

The University of California, San Francisco (UCSF) is expanding its Mission Bay and Parnassus Heights campuses to support advanced medical research, patient care, and education. This project faces unique challenges due to San Francisco's seismic risks, dense urban environment, and tight construction timelines. Structural shoring systems play a key role in ensuring safety and stability during excavation and construction near active facilities.

Key Highlights:

Seismic Safety: Special shoring systems handle unstable soils prone to liquefaction and ground movement.
Urban Constraints: Construction occurs near occupied buildings and critical utilities, requiring precise planning.
Shoring Solutions: Techniques include soil nail walls, tiebacks, and retaining walls tailored to site-specific needs.
Technology Use: Tools like Building Information Modeling (BIM) streamline planning and prevent conflicts.
Collaboration: Integrated Project Delivery (IPD) ensures smooth coordination among engineers, contractors, and stakeholders.

This expansion demonstrates how careful planning and advanced engineering can overcome the complexities of urban construction while maintaining safety and minimizing disruptions.

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Project Challenges and Site Constraints

The UCSF campus expansion brought a host of challenges that shaped the design and execution of the structural shoring systems. These hurdles stemmed from San Francisco's distinct urban environment, requiring tailored engineering approaches to ensure both safety and functionality. Here's a closer look at the key obstacles and how they were addressed.

Seismic Risks and Soil Conditions

Being in a region prone to earthquakes, the project had to account for demanding seismic conditions. The soil at the expansion sites - composed of bay mud and artificial fill - is highly susceptible to liquefaction during seismic activity. This meant the shoring systems needed to handle uneven soil strength, potential settlement issues, and lateral movements. To address these unique conditions, engineers implemented anchoring and bracing methods specifically designed to adapt to the site's unpredictable soil behavior.

Urban Density and Proximity to Existing Structures

The dense urban layout of the UCSF campuses added another layer of complexity. Construction sites were often located right next to active facilities, making it essential to design shoring systems that minimized any risk of settlement or structural movement. Complicating matters further, underground utility networks crisscrossed the area, and staging space was extremely limited. These challenges demanded meticulous planning, precise coordination, and creative installation techniques to ensure the project progressed smoothly without disrupting nearby operations.

Regulatory and Scheduling Constraints

Strict seismic codes and regulatory requirements presented additional hurdles. Oversight agencies required exhaustive documentation, which added to the project's timeline. Environmental regulations unique to the San Francisco Bay Area also influenced decisions around excavation methods and equipment selection. On top of that, the project had to meet tight deadlines to align with the operational needs of UCSF's academic and hospital facilities. This called for shoring systems that could be installed and dismantled quickly, all while adhering to stringent safety and regulatory standards.

Shoring Systems and Engineering Solutions Used

To tackle the seismic challenges and urban density issues discussed earlier, UCSF's expansion required carefully designed shoring systems. These systems were tailored to match the unique soil conditions, proximity to existing structures, and seismic demands at each site. Here's a look at the shoring systems used across UCSF projects.

Types of Shoring Systems Used

At the UCSF Parnassus campus, engineers utilized soil nail and shotcrete walls for temporary shoring. For underpinning work, they relied on manually excavated underpinning piers and tiebacks to support the existing spread foundations [1].

The UCSF Barbara and Gerson Bakar Research and Academic Building required two specialized shoring walls. According to project details, these walls were critical "to hold back the mountain and define the footprint of our site" [2].

For the UCSF Parnassus Heights Fuel Tanks Project, a retaining wall with tiebacks was chosen to stabilize the soil during excavation [3].

These examples highlight how engineers selected systems based on site-specific challenges and requirements.

Engineering Factors for System Selection

The choice of shoring systems hinged on several factors, including soil stability, seismic risks, and the limited space available for staging. In areas with unstable soils, more robust anchoring systems were essential, while stable zones allowed for lighter solutions. Each system was designed to handle potential ground movement while keeping vibration and settlement to a minimum - an important consideration for nearby active facilities. The tight urban environment also dictated which installation methods could be feasibly employed, ensuring both safety and efficiency.

Team Collaboration and Construction Methods

UCSF's shoring operations were a testament to the power of precise teamwork and modern construction techniques. With a range of key players involved - from university administrators to specialized contractors - effective collaboration played a central role in addressing the technical challenges of urban institutional projects.

Integrated Project Delivery and Lean Construction

To tackle the complexities of its campus expansion projects, UCSF employed Integrated Project Delivery (IPD). This approach brought architects, engineers, contractors, and stakeholders together early in the process, paving the way for seamless coordination. For shoring operations in particular, this collaboration was crucial, as design decisions had a direct impact on construction sequencing and safety measures.

Through IPD, shoring contractors were able to contribute during the design phase, helping to identify potential conflicts - like those between excavation plans and existing utilities - before they became costly issues. This proactive approach significantly reduced the need for change orders compared to more traditional project delivery methods.

Adding to this efficiency, lean construction principles were implemented to cut down on waste and improve workflow. Daily coordination meetings among shoring crews, structural engineers, and project managers ensured that challenges, such as soil conditions or equipment access, were addressed promptly. These principles also enabled just-in-time delivery of materials, minimizing on-site congestion and improving communication between suppliers, contractors, and site managers.

Together, IPD and lean construction set the stage for efficient shoring operations, ensuring that the project stayed on track despite the complexities of the site.

Building Information Modeling (BIM) Applications

Beyond manual coordination, UCSF leveraged Building Information Modeling (BIM) to enhance planning and execution. BIM technology allowed teams to visualize how temporary systems, permanent structures, utilities, and nearby buildings interacted, making it easier to coordinate shoring with other construction activities.

One standout application of BIM was clash detection, which helped identify conflicts between proposed tieback anchors and underground utilities before excavation began. This was particularly valuable at UCSF, where the subsurface environment was highly intricate and required meticulous planning.

BIM also enabled constructability analysis, allowing engineers to simulate different installation sequences. This helped them determine the most efficient approach while maintaining structural stability, ultimately reducing installation times and improving safety margins.

Additionally, BIM supported 4D scheduling, which linked construction activities to specific timeframes. This feature helped project managers visualize how shoring operations would progress alongside other trades, pinpoint potential bottlenecks, and allocate resources more effectively. These digital tools were instrumental in addressing seismic risks and navigating the challenges of a dense urban site.

Construction Phasing and Disruption Management

Careful planning around construction phasing was key to balancing hospital operations with worker safety. With active medical facilities on campus, minimizing disruption was non-negotiable.

Noise and vibration management became a top priority during shoring installation. High-impact activities were scheduled during periods of lower patient activity, with daytime operations typically preferred to reduce disruptions to sensitive areas like operating rooms.

Phased excavation allowed shoring to be installed in sections, maintaining both structural stability and continuous operations. Meanwhile, emergency response protocols were in place to handle equipment failures or unexpected ground conditions without interrupting medical services. These protocols included plans for deploying backup shoring systems quickly if needed.

Utility coordination was another critical element. Temporary rerouting of utilities was planned well in advance, with backup systems installed to ensure that essential services - like emergency power and medical gas - remained uninterrupted.

Finally, progressive monitoring systems were used to track ground movement and structural performance. Automated equipment provided real-time data on settlement and lateral movement, allowing teams to adjust construction methods as needed. This continuous monitoring added an extra layer of safety and ensured smooth operations throughout the project.

Lessons Learned and Best Practices for Urban Institutional Projects

The expansion of the UCSF campus offered a wealth of insights that go well beyond the scope of a single project. These takeaways serve as a guide for contractors, engineers, and project managers working on complex urban projects where maintaining operational continuity is critical.

Key Lessons from the UCSF Project

Early geotechnical investigations saved time and money. By thoroughly analyzing the site, engineers were able to choose the right systems to handle varying soil densities and groundwater conditions. This proactive approach helped avoid delays caused by unexpected subsurface challenges.

Involving shoring contractors early on minimized conflicts. Early collaboration allowed teams to address potential issues upfront, leading to fewer change orders and showcasing the cost-saving benefits of integrated planning.

Real-time monitoring systems ensured safety. Automated tools provided continuous data on ground movement and structural performance, enabling teams to respond quickly to evolving conditions.

Phased scheduling aligned construction with hospital operations. By coordinating high-impact activities around hospital needs, the project maintained safety and avoided disruptions. Careful planning reduced risks and kept costs under control.

BIM technology prevented costly mistakes. Tools like clash detection and 4D scheduling helped teams visualize underground utilities alongside tieback anchors, reducing the likelihood of utility strikes and unnecessary rework.

These lessons highlight strategies that can be applied to similar urban institutional projects, ensuring both technical success and operational harmony.

Best Practices for Structural Shoring in Urban Areas

Incorporate updated utility mapping during pre-construction. Dedicate extra time to mapping and coordinating utilities, as urban infrastructure often deviates from original plans. This step can significantly reduce delays and change orders.

Use redundant monitoring systems for critical structures. Pair automated systems with manual checks to ensure accuracy. Set conservative alert thresholds to allow enough time for corrective actions when needed.

Develop detailed noise and vibration management plans. Work closely with facility operators to identify sensitive areas and schedule activities during appropriate timeframes. Consider quieter methods, like drilled shafts instead of driven piles, when working near critical operations.

Prepare robust emergency response protocols. Include procedures for deploying backup shoring systems and coordinating with the facility’s emergency teams to address structural or operational concerns quickly.

Leverage technology for real-time collaboration. Beyond BIM, use project management platforms that facilitate instant communication between field crews, engineers, and operators to adapt to fast-changing conditions.

Anticipate utility conflicts. Budget for additional utility locating services and use non-invasive methods like ground-penetrating radar. Have pre-approved procedures in place for temporary utility rerouting to minimize delays.

Maintain clear communication with facility operators. Schedule regular coordination meetings to provide updates and give advance notice of any activities that could impact operations.

The UCSF expansion underscores that success in urban institutional projects requires more than technical know-how. It calls for a balanced approach that integrates engineering expertise with the operational needs of the surrounding environment. These best practices lay the groundwork for tackling similar challenges in other densely populated urban settings.

Conclusion

The UCSF campus expansion showcases how thoughtful shoring techniques can address the complexities of urban construction. Kelly Lyon, Project Manager in UCSF Real Estate's Campus Design and Construction, highlighted the scope of the Parnassus Heights project:

"The work has included constructing a foundation system for the building and creating two shoring walls to 'hold back the mountain and define the footprint of our site.'" [2]

FAQs

How do the soil conditions at UCSF's expansion sites impact the choice of shoring systems?

The soil conditions at UCSF's expansion sites present unique challenges due to the presence of materials like Dune Sand and a mix of soil types (classified as Type A, B, and C). These varying conditions significantly influence the choice of shoring systems, which are essential for maintaining safety and structural integrity during construction.

In areas where the soil is less stable, engineers often rely on soldier pile and tieback shoring systems to provide the necessary support. By thoroughly analyzing soil composition and stability, they can implement solutions tailored to the project's specific needs, ensuring the construction process remains both safe and efficient.

How does Building Information Modeling (BIM) help manage the challenges of large urban construction projects like the UCSF campus expansion?

Building Information Modeling (BIM) plays a crucial role in managing the intricate demands of large urban construction projects. It provides a shared, highly detailed 3D digital model that enables architects, engineers, and contractors to collaborate more effectively. By allowing teams to visualize and coordinate every element of a project ahead of time, BIM helps reduce design conflicts, cut down on errors, and streamline workflows - especially in the tight spaces of urban environments.

Beyond coordination, BIM improves safety and efficiency by identifying potential hazards early in the planning process. Its centralized data system enhances communication between teams and simplifies project handovers. This ensures not only better organization but also safer and more efficient construction sites.

How does Integrated Project Delivery (IPD) improve shoring projects in busy urban areas?

Integrated Project Delivery (IPD) transforms shoring projects in busy urban areas by encouraging early collaboration among key players like engineers, contractors, and project managers. This teamwork-focused approach fosters open communication, reduces potential conflicts, and speeds up decision-making - crucial elements when dealing with the complexities of city construction.

By emphasizing shared risks and rewards, IPD aligns everyone's objectives, pushing the team to come up with creative solutions that address the specific hurdles of urban projects. The payoff? Improved efficiency, fewer delays or unexpected changes, and a stronger focus on safety - critical for shoring operations in bustling cities like San Francisco or other high-density areas.