Project Description

The SR-91 Corridor, located in Orange County and Riverside County, California, along SR-91 is approximately 14 miles long, passes through the City of Corona and intersects I-15.  Approximately 280,000 motorists use this corridor daily, and that number is estimated to grow to 420,000 by 2040. The improvements consisted of adding general purpose and express lanes; interchange improvements such as bridges, ramps and connectors, and retaining walls; and associated modifications to SR-91 and I-15.  DYA was a subconsultant to URS Corporation (now AECOM), the Engineer of Record for the Design/Build project.  DYA prepared 13 foundation reports for mechanically stabilized earth (MSE) walls and tie-back walls.  The scope of work consisted of the following tasks:

• Reviewing available geotechnical data from geotechnical subsurface exploration and laboratory testing performed by URS (AECOM).
• Performing engineering evaluations and analyses to develop foundation design and construction recommendations.
• Preparing a final foundation report (FFR), presenting findings, conclusions, and recommendations for each wall.
• Submitting the FFR to comply with the Design Quality Management Plan protocols specific to the project.
• Providing responses to Inter Disciplinary Review and Constructability Review comments.
• Incorporating the review comments and submitting the final FFRs to the Design/Build team.

DYA's principal engineer performed independent technical review of the FFRs to make sure the reports were prepared in accordance with Caltrans' latest guidelines.

Christopher M. Diaz, PE, GE – Geotechnical Manager

V. R. Nadeswaran, PE, GE, ENV SP – Geotechnical Principal

Saroj Weeraratne, PhD, PE, GE – Geotechnical Associate Engineer

S. Niranjanan, PE, GE – Geotechnical Associate Engineer