Analysis of prevention measures for the environmental effect of vacuum combined surcharge preloading

Abstract Soft soil is widely distributed in the Pearl River Delta region of China. In the process of treating soft foundations, it is important to consider not only the effect of preloading consolidation but also the impact of construction on the surrounding environment. This article focuses on the soft foundation reinforcement treatment project of a municipal road in Hengqin, Zhuhai, and utilizes finite element software ABAQUS to establish a vacuum-combined preloading soft foundation reinforcement model. Six working conditions are set up for two prevention and control measures: digging side ditches and driving cement mixing piles. The changes in soil deformation caused by these measures are analyzed with different distances from the reinforcement area boundary, different ditch depths, and different pile lengths. The results indicate that excavating side ditches and installing cement mixing piles can effectively reduce deformation of the outer soil. As distance from the side ditch (or cement mixing pile) increases, their weakening effect on deformation gradually decreases. Excavating side ditches can achieve a weakening effect within 8-10 meters outside the ditch, while installation of cement mixing piles has an approximate range of 7-10 meters on both inner and outer sides of the piles. Furthermore, excavating side ditches shows better reduction in horizontal displacement compared to driving cement mixing piles at a lower cost. These research findings provide valuable insights for widespread application of vacuum-combined preloading methods in soft foundation treatment within the Pearl River Delta region.