地下综合管廊穿越桥梁引起桩基变形控制研究

Control of Pile Foundation Deformation Caused by Underground Utility Tunnel Crossing Bridge

在地下综合管廊施工中,基坑开挖会使土体应力发生改变,导致既有结构产生较大位移。以益州大道南二段综合管廊项目为依托,使用有限元软件进行模拟,得出分别采用基坑两侧施加支护桩、地下连续墙和注浆加固3种方法对既有桩基承台水平位移的控制均有一定效果,其中支护桩和地下连续墙可使承台原有位移减小45%~51%,有效控制了周边土体及结构变形;注浆加固可使其位移减小34%~45%,在一定程度上降低了施工风险。因此,对于此类工程,在实际施工过程中采用合理的控制方案十分重要。

The excavation of foundation excavation in the construction of underground utility tunnel will change the soil stress,resulting in large displacement of the existing structure.Based on the utility tunnel project,the finite element software is used for simulation.It is concluded that the application of supporting piles,diaphragm wall and grouting reinforcement on both sides of the foundation excavation has a certain effect on the control of the horizontal displacement of the existing pier.The supporting piles and diaphragm wall can reduce the original displacement of the cap by 45%~51%,the deformation of surrounding soil and structure effectively controled.The grouting reinforcement can reduce the displacement by 34%~45%,the construction risk is reduced to a certain extent.For such projects,it is very important to adopt the correct control scheme in the actual construction process.