Emergency Response – How Grouting Methods Have Come to The Rescue-Paper

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The paper presents four case histories showing how grouting can rapidly address unexpected ground loss, settlement, and water inflow during construction.<br /><br />At a municipal pump-station excavation, an obstruction prevented sheet piles from reaching their required depth. Uncontrolled soil loss caused surface settlement of up to 4 ft and threatened a future crane platform. Low-mobility grouting improved the disturbed ground, while a tangent-pile wall addressed the underlying support-of-excavation problem. Construction then continued without further issues at the breach.<br /><br />At a riverfront excavation, deflection of existing sheet piles opened a gap in the groundwater cutoff, and inflow exceeded the permitted discharge rate. Jet-grout columns sealed the area around the gap; connecting the sheet piles also reduced their movement. After remediation, seepage was manageable with intermittent pumping.<br /><br />Near the Washington Monument, leaks through a deep excavation’s cutoff wall drove inflow to about 300 gallons per minute and lowered nearby groundwater levels. Recharge wells helped stabilize water levels, while targeted and large-scale permeation grouting—primarily sodium silicate—substantially reduced leakage. Excavation resumed as groundwater levels recovered.<br /><br />On an interstate highway, deterioration of a culvert allowed soil to wash away, creating sinkholes and voids beneath the roadway. After the culvert was relined to stop further soil loss, low-mobility grout filled voids and improved disturbed ground. The highway reopened to normal traffic.<br /><br />Across the cases, grouting methods were selected according to site conditions, risks, schedule, and desired outcomes. The authors conclude that grouting can be an effective emergency response, but that alternatives should be assessed carefully for each situation.

Keywords

grouting

ground loss

settlement

water inflow

excavation

jet-grout columns

permeation grouting

sheet piles

sinkholes

groundwater cutoff