Comparative Analysis of Settlement for Soft Soil Foundation Reinforcement in the Road and Bridge Transition Section

In order to compare the reinforcement effects of anti-slide piles and CFG piles, taking an expressway soft soil foundation of road and bridge transition as an example, the surface settlement in Z direction after anti-slide piles and CFG piles are simulated and calculated based on FLAC3 D software. The calculation result within 20 m behind the stage is: (1) the anti-slide pile only has a strengthening and compaction effect on part of the soil around the pile, and has a very weak strengthening effect on the soil more than 1 m away from the pile, the vertical displacement is respectively 0.62~13.28 cm at different distances. In the CFG pile reinforcement scheme, the settlement of the area of pile center spacing with a distance of 1.8 m and 3.6 m is respectively within 2.5 cm and 4 cm, there is no soil failure and sliding failure in the foundation of the reinforcement area. Therefore, CFG pile is adopted as the reinforcement scheme in this project. The actual CFG pile was tested for a single pile vertical static load and settlement monitored, the total settlement value of the pile top was 3.89 cm at a distance of 20 m from the abutment, which was anastomosed with the numerical simulation results. The results show that the CFG pile can effectively reduce the plastic zone of the foundation soil, improve the bearing capacity of the foundation and reduce the settlement.