Permeation assessment of suspension-type grout using a novel centrifuge permeation setup

Permeation grouting is a ground improvement technique utilised to mitigate geotechnical disasters such as soil liquefaction. This study focuses on the use of suspension-type grout due to its potential for additional soil densification and material versatility. While centrifuge modelling can be utilised to assess permeation behaviour, testing under increased gravitational acceleration creates complications, including the accelerated settling of grout particles and challenges concerning remote operation. To overcome these limitations, a novel permeation setup was developed, featuring a modified bladder tank that enables remote permeation while preventing grout sedimentation. This was paired with a two-dimensional permeation apparatus designed to visualise the process while minimising boundary effects. Results confirm that controlled permeation was successfully initiated and sustained within the centrifuge field. This allowed for a clear assessment of grout flow, including the clogging mechanism and sedimentation. Image analysis further revealed that unclogging events led to an increased permeation area and that the particles remained stable and confined to the target zone post-permeation. The study successfully establishes a geotechnical centrifuge methodology for permeation experiments, generating foundational data that will enable future complex investigations into depth and soil variables necessary to enhance the efficiency of grouting as a soil remediation technique.