Application of Jet Grouting and Cutter Soil Mixing in Ice-Rich Soils-Paper

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The study evaluated cutter soil mixing (CSM) and jet grouting as methods to reduce liquefaction risk beneath a tailings dam at Red Dog Mine in remote northwest Alaska. The foundation included loose native coarse soils, some frozen and ice-rich, beneath site-development rockfill. Thawing could weaken the soils and contribute to settlement or seismic failure.<br /><br />A field trial compared six jet-grout clusters and five CSM panels, testing variations in predrilling, water pre-cutting, mix designs, and construction parameters. Treated samples were assessed through unconfined compressive strength, tensile strength, and elastic-modulus testing, as well as coring and borehole surveys.<br /><br />Both methods successfully formed soil-cement elements in frozen, potentially ice-rich ground. Most tested samples met the target compressive strength of 350 psi (2.4 MPa). However, cores showed inconsistent treatment in several jet-grout columns, with poorly or untreated zones that broadly corresponded to areas where ice-rich soil had been identified. CSM produced more uniform treatment; its core quality was generally better, particularly in predrilled panels. Predrilling also shortened installation time by about 30 minutes, though CSM could be installed with or without it.<br /><br />CSM was selected for the full-scale mitigation program because of its more consistent treatment. The chosen mix used a single-phase process, a water-cement ratio of 0.6, and a binder content of 350 kg/m³. The trial demonstrated that CSM could treat frozen and potentially ice-rich soils without special measures to thaw them first.

Keywords

cutter soil mixing

jet grouting

liquefaction mitigation

tailings dam

Red Dog Mine

frozen soil

ice-rich soil

soil-cement

predrilling

unconfined compressive strength