The Study About The Influence Ofdeep Foundation Excavation On Bridges Existed

In the recent years, with the development of urban construction, more high-rise building has been built and the underground space has been utilized fully, bringing more deep excavation engineering. Especially in recent10years, a lot of foundation pit that deeper than20m has been dug. However, it has also brought many engineering accidents———the movement of a great deal of soil in urban could made buildings nearby incline or crack、 damage of the road and pipeline fracture,threatening the safety of city bridge engineering. Therefore, the problem of ground deformation brought by the digging of deep foundation pit has been paid more attention to.In order to know the displacement caused by the digging of deep foundation pit and assess the safety influence that brought by it, and also to find the scientific basis to solve these problems, we analyze and monitor Chengdu south railway station Rennan overpass E-ramp influenced by capitaland commercial project deep foundation pit, including follow jobs:(1) Summarize the safety assess method of the bridge influenced by the digging of deep foundation pit. On the basis of theoretical analysis method, we make imitative analysis on the process of the digging of deep foundation pit, and assess the influence initially;(2) Set up safety supervision system for E-ramp on bridge main piers、pile foundation、 floor system、wall protection piles of foundation pit by using construction safety monitoring system and collecting information regularly. Then, we analyze and process data to draw a conclusion:(3) By using large bridge finite element software MIDAS/CIVIL, we calculate and analyze E-ramp. assess the performance of the whole bridge after digging the deep foundation pit.