Each year, CalGeo puts the spotlight on the best geotechnical projects in the state with their Outstanding Project Awards. A panel of peers selects the year’s finest work in a number of categories, providing winners with a powerful new marketing message and everyone with the opportunity to learn from exciting, innovative approaches to challenging situations.
On March 10, 2022, the 2021-22 CalGeo Awards were announced. ENGEO is thrilled to receive an Award for 1450 Bayhill Drive (YouTube) Shoring in the Private-Large Category and an Honorable Mention for Riverside Elementary – Lateral Spreading Restraint Element Design in the Public Medium Category.
YouTube’s new office structure, Building 3, located at 1450 Bayhill Drive, San Bruno, California includes four levels of below-grade parking. Construction of the garage required installation of a hybrid soil nail, tie-back, and cantilevered soldier pile shoring system up to 70 feet deep. The excavation is located between a Caltrans embankment and two San Francisco Public Utilities Commission (SFPUC) water transmission lines that are the main source of water to San Mateo County and the city of San Francisco. Due to proximity to sensitive infrastructure, ENGEO created a monitoring instrumentation plan, analyzed expected deformations using numerical modeling, and calibrated the models to measured deflections. ENGEO led weekly meetings with SFPUC to present the measurements and predictions of future movements. ENGEO provided engineering/geology observation throughout construction. The project was successfully completed between December 2020 and June 2021. Throughout construction, the SFPUC pipelines remained fully serviceable and the Caltrans embankment was unaffected.
The Riverside Elementary Lateral Spreading Resistance Element (LSRE) project (Project) was constructed through a design/build procurement. The project is located in San Pablo, California and is part of the West Contra Costa Unified School District (School District). ENGEO supported the design/build team and brought innovation and led an in-process review by the School District and State of California Division of State Architect (DSA)/California Geological Survey (CGS) to make the project successful. The Project sits adjacent to and above Wildcat Creek.
ENGEO performed design services for the design-build construction of a mitigation of liquefaction-induced lateral spreading adjacent to a Bay Area elementary school. Overlapping deep soil mix (DSM) columns were constructed to create shear panels in the ground parallel to the direction of possible soil movement.
ENGEO performed analyses to design the DSM panels and prepared the construction drawings and specifications in-house.
The project schedule allowed for slightly more than five months to perform the design, achieve concurrence by the School District’s Geotechnical Engineer, and gain approval by the State of California in order to start construction in the School District’s required timeline.