DSM-Agnews

Project Name: Agnews K-12 Campus, Cement Deep Soil Mixing
Location: San Jose, CA
Owner: Santa Clara Unified School District
General/Prime Contractor: Swinerton
Construction Sector: Non-Residential, Educational
Ground Improvement: Deep Soil Mixing (DSM)

Project Highlights

  • Ground Improvement by Cement Deep Soil Mixing (CDSM) for Seventeen Buildings comprising an Elementary School, Middle School, High School, and Accessory Buildings. Footprints of buildings vary from 1,800 square feet to 34,000 square feet.
  • Cement Deep Soil Mixing Walls in the grid pattern under each building.
  • Total CDSM volume installed about 221,000 cubic yards.
  • Total CDSM element ( 4-Augers/columns) installed about 2,500.
  • CDSM element average depth about 41 feet.
Overall CDSM in Agnews Project

Purpose

  • To mitigate the site liquefaction hazard.
  • Provide vertical and lateral support of buildings shallow foundation systems, for both static and seismic loadings.
  • Transfer bearing loads to the dense to very dense layers reducing total and differential settlements.

Generalized Sub-Surface Profile

  • 0 to 20 feet bgs, very stiff brown lean clay, water content 20%
  • 20 to 30 feet bgs, soft to medium lean clay with sands, water content 25%
  • 30 to 40 feet bgs, medium-stiff lean clay with sands & gravels, water content 30%
  • 40 to 50 feet bgs, dense coarse sands with gravels, water content 15%