Effects of Deep Soil Mixing and Jet Grouting Construction Process on the Performance of Braced Excavations

Ground improvement methods, such as deep soil mixing (DSM) and jet grouting piles (JGP), are widely used to stabilize soft soils in underground construction. However, the construction processes themselves cause movements and pore water pressure changes in the adjacent ground and can potentially impact adjacent structures. To mitigate these detrimental effects, the mechanisms of ground movements during ground improvement processes need to be well understood and controlled during construction. This paper presents observed response in the surrounding soil and structures caused by the installation of DSM and JGP and highlights the importance to consider the installation effects. Simplified methods have been developed to incorporate the installation process in the finite element analysis of braced excavations, to explore the installation effects on the braced excavation. Computed results suggest that neglecting the installation effects may underestimate the excavation performance.