Case Study: San Francisco Bay Bridge East Span Design Flaws Lead to Steel Fabrication Rework (2016)

Project Overview
• Name: San Francisco-Oakland Bay Bridge East Span Replacement
• Location: San Francisco, California
• Year: 2016
• Project Size: $6.4 billion
• Scope: Construction of a self-anchored suspension bridge span
• Lead Agencies/Contractors: Caltrans /

Category of the Issue, Problem, or Challenge
• Design
• Structural Engineering

Summary of the Issue, Problem, or Challenge
Critical design flaws in steel connection details were discovered during fabrication, requiring extensive redesign and re-fabrication of large steel components. The issues involved miscalculations of load transfer and insufficient fatigue detailing, threatening the structural integrity and schedule.

Root Cause Analysis

• Overly complex design leading to fabrication challenges.
• Insufficient early-stage design validation and load testing.
• Communication gaps between design engineers and fabricators.
• Lack of adequate peer review on critical connection details.

Impacts Due to the Issue, Problem, or Challenge
• 9-month delay due to re-fabrication and testing of steel elements.
• Cost overruns estimated at $20 million.
• Heightened safety and quality audits throughout project.

Corrective Actions Taken

1. Redesigned steel connections with simplified and robust detailing.
2. Instituted rigorous design validation and peer review processes.
3. Improved communication channels between designers and fabricators.
4. Enhanced quality control procedures during fabrication.

Lessons Learned

• Complex structural designs must be validated early and thoroughly.
• Peer reviews can identify critical flaws before fabrication begins.
• Fabricator input during design development improves constructability.
• Effective communication prevents costly design-fabrication disconnects.

Audit & Prevention: Project Control Questions to Ask on Future Projects to Help Control the Situation

• Are complex design details validated with prototypes or models?
• Is there a formal peer review process for critical structural elements?
• Are fabricators involved early to provide feedback on design feasibility?
• Are communication protocols clear and enforced between design and fabrication teams?