Supporting Structure Design And Stability Analysis Of Deep Foundation Pit Of Zhonghang Square Stage ?

The supporting structure of the deep foundation pit of Zhonghang Square Stage2 is on the west of Nanchang 81 bridge.The area of the pit is 6701.9m2,and the perimeter is 325.91 m.The southern part of the Natural terrace is about 4.5m higher than the northern part,and the ground water source is rich in this area.The supporting structure uses cantilever pile and soil nail wall to support the foundation pit.In the northwest corner,the cantilever pile is designed into Z-shaped.By utilizing the space integral function of cantilever pile,the project cost would be decreased.In view of the situation that the displacement of the cantilever retaining pile of the eastern pat of the foundation pit is too big,we discussed the impact of prestress rowed piles supporting.Technique on the shape changing effect of the foundation pit.The main designing and study content includes:(1)Uses Li Zheng Deep Excavation,PLAXIS software to design the supporting structure analyze the stability of the foundation pit of Zhonghang Square Stage 2.(2)In the northwest corner of the foundation pit of Zhonghang Square Stage2,the cantilever pile is designed into mansard to fully utilize the space effect of mansard.By doing finite element analysis using MADIS GTS,if we consider about the space effect,we can get the result that the max horizontal displacement is27.97 mm,and the max bending moment is 675 KN ?m.However,if we ignore the space effect,we can get the result that the max horizontal displacement is27.97 mm,and the max bending moment becomes 1115 KN ? m,and this cannot satisfy the code requirement.By contrast with actual measure value,we can get the code requirement.By contrast with actual measurement value,we can get the conclusion the Z-shaped cantilever pile is a reasonable design and it can apparently decrease the project cost.(3)The depth on the east of the foundation pit is 9.5m.Due to the conditionality,prestressded anchor ropes and piles form of support would not be applied.After all the studies of form of support to built prestress in cast-in-place pile,and analyses on the outcome of the support under various soilparameters,prestress piles indicate the best prospect based on the evidence that there would be a significant decrease rate,28.61%-53.79%,of the foundation on pit's horizontal displacement.(4)Regards to the middle pit of Zhonghang Square Stage 2's support project,PLAXIS software would be used to do design and analysis about how the outside slope impacts the inside supporting force and stability parameter.According to the result,when the distance between outside slope ans inside slope is short,the force,displacement,and coefficient against inside slope be affected and influenced.We have the obligation to think highly of this situation while designing.