City Of Dearborn Tackles Complicated Grout ‘Curtain’ Project

By Jeff Griffin, Senior Editor | April 2010 Vol. 65 No. 4
Production oriented drill rigs during drilling of grout holes. (Source: Layne GeoConstruction)

After grouting, the contact zone and bedrock grouting programs were tested to determine if the residual permeability goal of 2 Lugeon was achieved. Several samples of the grouted contact zone were retrieved which provided further indication that the contact zone had been successfully grouted. A pump test performed at the end of rock grouting revealed that the residual permeability of the rock formation and contact zone had actually been reduced to an even lower value of 0.2 Lugeon.

After successfully sinking the caisson, excavation of the bedrock formation at Contract 8 revealed that inflow was minor and easily controlled using a conventional construction sump pump.

Excavation of bedrock at Contract 8 is nearly complete, and bedrock excavation is proceeding at Contract 7. Grouting consultant Naudts concluded: “This is an incredible result, a remarkable achievement about which everyone who worked on should be proud.”

Grout Details
Acrylamide is a monomer used as an aqueous solution in geotechnical grouting applications. Three components are mixed together to obtain a polymer grout. The acrylamide grout is a liquid without suspended solids and has the viscosity of water which penetrates the pore volume of the soil matrix and quickly changes from a liquid to a gel-type solid. In a time period predetermined for site conditions, acrylamide grout can be made to set up in seconds, minutes or hours. On this project, gel times were longer in the mornings, and shortened throughout the day.

Layne GeoConstruction, (804) 448-8060,
Avanti International, (281) 486 5600 or (800) 877 2570,
NTH Consultants Ltd, (313) 237-3900,
ECO Grouting Specialists Ltd, (519) 928-5949,

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