Analysis On Deformation And Stability Of A Foundation Pit Of Suzhou Xianrenda Port Project

With the rapid development of cities constructions and its supporting construction, such as hydraulic project, ports and docks, more and more foundation pits appeared. For foundation pits, because of long project period, high costs and so much difficulty in excavation, how to analyze excavate deformation reasonable has become a focus in civil engineer.In this paper, basing on the analysis on the supporting structure form, deformation calculation methods in excavation and affecting factor for calculation, the author build the finite-element model, some researches on stress, displacement of the key points and change fields. According to the calculated date, analysis on deformation and stability are done.Foundation pit deformation controlling is very important for the pit supporting structure security and the surrounding constructions. By the analysis on horizontal displacement of pit supporting structure, ground fallout and pit base apophysis, etc. Then the model is calculated, the results show that because of the high water head of artesian water, tensile region in the bottom of pit will be very large after the opposite aquifuge is excavated; Using dewatering wells to reduce water head, pumping influenced radius is 26.7m if the well depth up to the fifth bottom surface, and this radius is 39.0m is the well depth up to the seventh bottom surface; As to the controlling point of the foundation pit, Supporting construction for foundation pit have a great effect on it's displacement, its maximum horizontal relative displacement is 11.00mm, and 29.9mm in the direction of vertical relative displacement. So, more attention should be paid on the construction monitor in the digging process. At the last, for the problem of the foundation pit that may emerge, considering set crosswise supporting beam, we design a new geometric model of the foundation pit, the calculating result indicated that the crosswise supporting beam can decrease the horizontal displacement of foundation pit distinctly, and at the same time , impact of construction processes to surroundings is decreased effectively.