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

PPT Presentation

Pdf Summary

At the Red Dog Mine in Alaska, potentially liquefiable soils beneath a wing wall required ground improvement. The site’s native coarse soils contained cobbles, boulders, and visible ice. Field trials compared jet grouting (JG) with cutter soil mixing (CSM), both designed to extend about 70 feet (21.3 m) and embed 3 feet (0.9 m) into bedrock.<br /><br />The JG trial used six clusters of three columns, with target diameters of 1.0–1.8 m. The CSM trial comprised five panels. Testing included wet-grab samples and core samples collected from vertical and inclined boreholes; stable holes were also examined using optical televiewer imaging.<br /><br />All JG wet-grab samples met or exceeded the target strength, and most cores did as well. However, cores from all three JG clusters showed stretches of poorly treated material in initially frozen native soils. CSM wet-grab and core samples met or exceeded target strength in all but one case. Overall, CSM produced more consistent treatment, with improved quality in pre-drilled panels.<br /><br />Both pre-drilled and non-pre-drilled CSM panels could be installed through the overlying soil, while pre-drilling reduced installation time by about 30 minutes. CSM effectively treated frozen, potentially ice-rich soils and met project requirements without special thawing measures. By contrast, variations in jet-grout column diameter and homogeneity across changing ground conditions posed a limitation.<br /><br />The successful trials informed production work: 660 pre-drill elements and 462 CSM panels were installed over the 2020 and 2021 construction seasons.

Keywords

Red Dog Mine

Alaska

liquefiable soils

ground improvement

jet grouting

cutter soil mixing

frozen native soils

bedrock embedment

soil stabilization

construction trials