My first Magazine dsi-info-23-en | Page 146

Construction — North America — USA — Hydro & Marine Structures

Safe from Floods with DYWIDAG Anchor Systems : Reinforcement of the Folsom Dam in California

Completed in 1955 , Folsom Dam is located on the American River in northern California , approximately 40km northeast of the city of Sacramento . The 100m ( 340ft ) high and 430m ( 1,400ft ) long dam creates the Folsom Reservoir that has a maximum possible water area of 4,830ha ( 11,930 acres ). The Folsom Power Plant has 3 Francis Turbines with a total output of 198.72MW .
In order to significantly lower the probability of floods and to double the amount of water the dam can hold in the event of flooding , the U . S . Army Corps of Engineers and the Central Valley Flood Protection Board cooperated with the state of California and the Sacramento Area Flood Control Agency to undertake the “ Joint Federal Project ” ( JFP ).
The JFP includes a new spillway with six submerged tainter gates located in a new control structure . This structure is an additional dam that prevents water from entering the spillway when the gates are closed . The project consists of 5 phases .
In phase IV of the construction , a 335.3m ( 1,100ft ) long approach channel is being built for the new spillway on the reservoir side . Essentially , this includes a second dam , the 922.6m ( 3,027ft ) long spillway chute and the stilling basin on the downstream side .
The stilling basin works as an energy dissipater to slow the water as it enters the American River .
In this phase , the soil for the additional dam and part of the spillway chute is excavated , and the foundation of the control structure is built .
For this purpose , DSI Construction USA supplied a total of 316 90mm Ø DYWIDAG
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