Effect of compaction grouting reinforce on deformation of deep foundation pit in metro station in active Zone

摘要

Adopting Hardening-Soil finite element model based on unloading, the improvement of grouting strengthening rear soil on deformation of the pit is studied. The results show that the reinforce influence on lateral deformation increases with the increasing of the excavating depth, the final lateral deformation reduces 13.6% than without reinforce, the displacement of pile top reduces 40.66%, but the displacement of pile bottom increases 13.27%; the uplift in bottom soil can be control in the area 6.00m near the wall, the range reduces 7.21% than without reinforce; It is conspicuous to reduce the soil settlement in the area 20.00m behind the retaining structure, the maximum settlement reduces 7.96% than without reinforce, the same as the lateral deformation of the soil in the area 20.00m∼30.00m behind the retaining structure, the maximum lateral deformation reduces 45mm, relative 26.45%. Therefore, grouting strengthening rear soil based on difference geological conditions and deformation requirements to improve the reinforced soil intensity to devised result, which can guarantee the pit safety and environment influencing, as well as enhance the anti-permeability capacity.