The largest cement deep soil mixing (CDSM) project in North America, this project required installing a remote monitoring survey system, removing a 140,000-cubic-yard buttress, installing 137,000 cubic yards of CDSM to maximum depths of 118 feet (average depth approximately 80 feet), and replacing a new buttress (approximately 280,000 cubic yards).
A study commissioned by the East Bay Municipal Utility District (EBMUD), in coordination with the California Division of Safety of Dams (DSOD), confirmed that the soils and foundation that make up the dam are susceptible to liquefaction. The study predicted that a magnitude 7.5 earthquake on the Hayward fault would cause the dam to slump and decrease in height sufficiently to allow water to flow over the top, resulting in a breach of the dam and flooding downstream.
Kleinfelder was selected to provide construction management services for this two-year-long project valued at $54.6 million. Our team was pivotal in achieving the project’s milestones and in maintaining the working relationships between the owner, design engineer, contractors, and agencies. Kleinfelder also provided EBMUD-associated project control support, quality assurance services, environmental/safety compliance monitoring, and assistance in addressing operational constraints in and around an active earth embankment dam and recreation area.
Kleinfelder’s oversight saved the client several million dollars in construction costs and avoided the significant environmental impacts associated with draining the dam’s reservoir to build a temporary pipeline. In addition, the Kleinfelder team saved water during a time of drought.
Location:
Contra Costa County, California
Owner:
East Bay Municipal Utility District (EBMUD)
