Perris Dam Seismic Remediation Project- Perris, California

Project Highlights

  • A Foundation study by the Department of Water Resources California (2005) indicated the sandy layers in the dam foundation as liquefiable.
  • Cement Deep Soil Mixing (CDSM)  in a cellular pattern was designed to maintain seismic stability.
  • A 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 the picture below.
  • In total 320,000 CY of the ground was improved by CDSM, which was about 42% area replacement ratio.
  • The installation patterns of the CDSM elements were Primary – Primary- Secondary.

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