Abstract: The foundation excavation area for the cable utility culvert has the characteristics of long and narrow, which is easy to induce excessive rebound deformation at the bottom of the excavation in soft soils and further adversely affect the project construction quality. Therefore, it was necessary to improv the bottom of the excavation by using high pressure jet grout method. The commercial ABAQUS software was used to study the influence of improvement depth, replacement ratio, properties of foundation soil and embedded depth of supporting soldier pile structure on rebound deformation at the excavation bottom. The results show that increasing the depth of improvement and the replacement ratio of the improvement area are effective measures to reduce the rebound deformation at the bottom of the excavation. However, when the improvement reaches a critical depth, the rebound reduction effect becomes not obvious, even if continue to increase the improvement depth. The improvement depth is more suitable between 4m and 8m for the cable utility culvert project. The deeper the embedded depth of the supporting soldier pile structure or the higher the strength parameter of the foundation soil, the smaller the rebound deformation of the bottom of the excavation. However, with the increase of improvement depth, both factors have less influence on the bottom rebound deformation.

Key words: Utility Culvert, Excavation Bottom Rebound, Soil Improvement, Numerical Simulation