Several media outlets have reported on a visible defect in a retaining wall now being constructed as part of the I-405 Sepulveda Pass Improvements Project in the Sepulveda Pass. Panels on a localized segment of the retaining wall at the future Skirball Drive on-ramp became displaced late last week. This section of the retaining wall has since been stabilized, and poses no safety risk for either freeway or street traffic. The contractor is now performing an investigation. Here’s additional information from a project e-mail that went out to 405 project constituents:
A MSE (Mechanically Supported Engineering) retaining wall, located along the southbound I-405 at Mountain Gate, suffered a localized failure on Thursday, December 1. The failure occurred on Caltrans right-of-way, west of the freeway, in our construction zone. No one was injured and our geotechnical team deemed the freeway and Sepulveda safe for the traveling public. Traffic has not been restricted at this location.
The wall, approximately 2,000 feet long, is part of the work to relocate the Skirball Center Dr on-ramps south of their present location on the Skirball bridge. The portion of the wall that has been compromised is only 20 feet long. The project has been aware of deficiencies in this portion of the wall for a few weeks and were preparing a partial deconstruction plan when the panels failed. The wall has been stabilized and there is no danger to the traveling public. The contractor is currently performing an in-depth investigation to the cause of the localized failure. Experts have been brought in to collect forensic evidence. We cannot speculate at this time as to what caused the failure. Once a thorough and complete investigation has been finalized and approved by Metro and Caltrans, the contractor will create a mitigation plan.
Until the investigation is complete, work on the other MSE walls along the project has been halted. Our path forward will be determined by the outcome of the investigation.
We appreciate your patience during this investigation. Please be assured that safety is our number one priority and we will work until we can guarantee that all work on the project is safe and stable.