Engineering Aspects of Jet Grouting and Its Applications for Seepage Control-Paper

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The paper examines jet grouting as a method for creating low-permeability cut-off walls to control seepage. The process uses high-pressure jets to break up and mix in-situ soil with cement-based grout, forming hardened columns without excavation. Single-, double- and triple-fluid systems are selected according to soil conditions and required column dimensions.<br /><br />Column performance depends on soil type, grout mix, jetting pressure and flow, nozzle configuration, rotation and withdrawal rates, column geometry, and treatment depth. For seepage barriers, overlapping columns must form a continuous wall extending to the required depth. Permeability is the key performance criterion, while strength testing alone may not reliably indicate barrier quality.<br /><br />A case study describes a cut-off wall for temporary cofferdams at a multipurpose irrigation project in India. The project treated approximately 66,000 m² using double-fluid jet grouting, forming nominally 2 m diameter columns at 1.5 m spacing. Laboratory studies and field trials established the grout mix and operating parameters. Quality control included monitoring grout properties and installation data, checking column diameter and verticality, and testing samples for permeability. At 56 days, tested samples met the target permeability of less than 10⁻⁸ m/s.<br /><br />Key construction challenges included maintaining column verticality and overlap, avoiding cold joints, managing variable soil conditions, collecting and testing numerous samples, and ensuring safety during high-pressure jetting. The paper concludes that jet grouting is a flexible, proven seepage-control technique applicable across many soil types and can be carried out near existing structures without lowering reservoir levels.

Keywords

jet grouting

seepage control

cut-off wall

low permeability

cement grout

double-fluid system

soil stabilization

permeability testing

cofferdam

quality control