Sacramento River East Levee Contract 4 – Construction of Seepage Cutoff Wall-Paper

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The Sacramento River East Levee Contract 4 (SREL4), part of the American River Common Features 2016 project, installed jet-grout cutoff walls to connect with walls built under earlier contracts. Treviicos Corporation constructed 99 columns, generally 8 or 10.5 feet in diameter and up to 145 feet deep. The walls were designed to achieve a minimum thickness of 36 inches, core strength of at least 200 psi, and specified low permeability.<br /><br />Triple-fluid jet grouting—using air, water, and grout—was the primary method. Single-fluid grouting was also used where site conditions or utility clearances required smaller equipment or additional ground stabilization. Work took place at the Sump 132 pump station, the Westin Hotel, and Broadway; the Marina location was reassigned to deep mixing.<br /><br />Construction involved difficult and variable ground, including dense gravel, wood debris, cobbles, loose breach fill, and voids. Constraints included active pump-station discharge pipes, a nearby hotel and public areas, limited working space, and a high-pressure gas line. Responses included using a water-powered hammer to penetrate obstructions, stabilizing loose ground with single-fluid columns, developing a hybrid single- and triple-fluid method, and coordinating monitoring and clearances with project partners and utility owners. At the hotel, sinkholes and grout-return losses required changes to the stabilization approach.<br /><br />Verification included core sampling, strength and permeability testing, in-situ permeability tests, and borehole inspection. Although some partial columns were needed to repair defects, testing generally met contract requirements. Through close coordination among Treviicos, the general contractor, and the U.S. Army Corps of Engineers, the cutoff walls were completed and accepted without damage to the nearby gas line or discharge pipes.

Keywords

Sacramento River East Levee Contract 4

SREL4

jet-grout cutoff walls

American River Common Features 2016

Treviicos Corporation

triple-fluid jet grouting

single-fluid grouting

deep soil stabilization

low permeability cutoff wall

U.S. Army Corps of Engineers