PLEASANTON, CALIFORNIA, USA, February 19, 2025 –
When historic storms hit the Bay Area in late December 2022, floodwaters surged through the Arroyo de la Laguna, submerging the private cart bridge that connected The Club at Castlewood. Within days, the structure collapsed under the weight of debris and extreme flows, exceeding even the predicted 100-year flood elevation. Left with no reliable crossing, the Club faced a costly disruption to operations, members, and maintenance services.
Within weeks of the disaster, structural engineers from PASE were on-site evaluating damage, guiding emergency response, and drafting proposals for a complete rebuild. But restoring access wasn’t a matter of rebuilding what once stood; it required a ground-up redesign to elevate the new structure more than 9 feet above its predecessor, clear environmental review hurdles, and safely span over 250 feet across the sensitive waterway.
The solution called for innovation under pressure. Geologic hazards at the north bank, including liquefiable soils and slope stability issues, required a foundation redesign using helical piles and stitch pile reinforcement. Access constraints on the south bank left crews with little room to stage equipment, leading to an ambitious bridge lift using a 300-ton crane operating at full reach. Meanwhile, environmental planning teams navigated complex permitting to keep construction fully out of the active channel.
Unanticipated field discoveries, including an 8-inch PVC water line running directly under a major abutment, forced real-time engineering adjustments. Through it all, PASE coordinated tightly with the owner, geotechnical and civil engineers, Contech (for the prefabricated steel superstructure), and Farrell Design-Build to keep the project moving forward with resilience and clarity.
The result? A structurally sound, elevated bridge now spans the channel. It is future-ready, flood-resilient, and designed for decades of service.
About PASE
PASE is a premier structural engineering firm specializing in mission-critical, multi-family/residential, and mixed-use structures. Our team is dedicated to delivering innovative, cost-effective, and sustainable engineering solutions tailored to the needs of our clients.
For more information on PASE and our completed projects, click here!
Media Contact:
Azlan Ezaddin, S.E.
Email: aezaddin@pase.com
Direct: 408-957-9228