Perris Dam Seismic Remediation Project- Perris, California

Project Highlights

  • Foundation study by Department of Water Resources California (2005) indicated the sandy layers in dam foundation as liquefiable.
  • Cement Deep Soil Mixing (CDSM)  in a cellular pattern was designed to maintain seismic stability.
  • Total of 72 cells including Shallow cells and Deep cells were installed along the dam toe  of 4100 feet long.
  • Each cell was approximately 55 feet by 120 feet with 5 to 7 transverse CDSM walls and 3 longitudinal CDSM walls, as shown in picture below.
  • In total 320,000 cu yds of ground was improved by CDSM, which was about 42% area replacement ratio.
  • The installation pattern of the CDSM elements were Primary – Primary- Secondary.

After the field validation test sections were completed, the test walls were exposed upto 5-10 feet deep as shown in picture below to show an intact CDSM. There were three elements in each test wall, each with 60 feet in depth.