Simulated Radial Expansion and Heave Caused by Compaction Grouting in Noncohesive Soils

Abstract

Compaction grouting is widely used for ground improvement, including foundation retrofitting, earthquake disaster mitigation, and settlement compensation. However, until now, it has been developed and used based on an empirical approach and on judgment, rather than on theoretical and analytical methodologies. Estimating the expansion of soils caused by compaction grouting under different depths, soil conditions, and injection pressures is critical to determining the design parameters and construction procedure, as well as to assessing the effectiveness of the ground-improvement measure. Different mechanisms and models are reviewed and evaluated. Graf’s model is among the most appropriate and readily understandable in the view of practitioners; the elastoplastic Mohr-Coulomb constitutive model was deemed appropriate for the finite-element analysis that was conducted in this study. Charts based on the finite-element simulation results of radial expansion and heave in noncohesive soils under different soil and construction conditions are presented to facilitate such an engineering application process. Moreover, the results are compared with case history data and Wong’s analytical failure model. A simplified procedure and examples of how to use the charts are also presented.