Installation of a Cutoff Wall Along the Mississippi River

PPT Presentation

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The East St. Louis Deep Cutoff Wall project, commissioned by the U.S. Army Corps of Engineers, involved constructing a 4,400-foot-long wall up to 142 feet deep along the Mississippi River. The wall was designed to be 24 inches thick, extend two feet into limestone, and provide specified strength and permeability. Ground conditions included gravelly sand, sand, silt, clay, and strong limestone.<br /><br />The main wall was installed as a single-phase cutoff wall using hydraulic grabs and a cutter, with slurry processing and desanding. Quality control included testing slurry properties, collecting wet samples from each panel at multiple depths, and measuring unconfined compressive strength and permeability. Excavation monitoring, verticality checks, and confirmation of rock embedment supported construction verification.<br /><br />At utility crossings, where sensitive infrastructure could not be disturbed, the team combined cutoff-wall panels with jet-grouted columns to create protective “windows.” Installation parameters, column verticality, grout properties, permeability, and continuity were monitored and verified through modeling, borings, and pump tests.<br /><br />The project faced difficult bedrock excavation, tight scheduling constraints, a trapped cutter, pandemic-related impacts, and severe slurry loss in a highly pervious gravel layer. Through close cooperation between the owner and contractor, the challenges were overcome. The completed wall met or exceeded performance requirements, and the project received a 2023 DFI Outstanding Project Award Special Recognition.

Keywords

East St. Louis

Deep Cutoff Wall

U.S. Army Corps of Engineers

Mississippi River

cutoff wall

jet grouting

slurry wall

quality control

bedrock excavation

DFI award