Deformation Control Research Of A Variety Of Supporting Foundation Pit In Soft Soil Regions

Foundation pit accident often causes very serious economic loss and social influence.People pay more and more attention on controlling the foundation pit deformation. Affected bythe load, the difference of the surrounding environment, as well as economic and other factors,the number of the foundation pit shared by a variety of support is increasing. Research ondeformation control and design methods of a variety of support are relatively scarce. Therefore,study of deformation control of common foundation pit with a variety of support formdeformation has important practical significance.This paper is based on Jinan low-rent Qinghe house foundation pit project. Takediscussion about deformation control in pile-anchor support and gravity retaining wall shareddesign and in soft soil by engineering experience analogy, finite element simulation, spotmonitoring and so on.Through the local engineering experience analogy and the finite element simulationanalysis, different forms can be choosed in one foundation pit according to the difference ofsurroundings. Taking a careful consideration about the carrying capacity of the surroundingenvironment (buildings, underground pipelines, etc.), choose a reasoned scheme which has alow cost and high economics. Considering synergy of the space under different workingconditions, the internal force and deformation calculation is more accurate and design is morereasonable by using spatial analysis methods. The space finite element simulation can providea variety of common deformation of foundation pit supporting forms with more accuratelypredict to guide the design and construction. The biggest displacement of the one common pitwith pile-anchor support and gravity retaining wall pile occurs near the middle of foundation pitpile on opposite sides. Increasing the ends thickness of the gravity cement-soil retaining wallcan reduce the amount of both ends displacement of the soldier pile retaining, It also cancoordinate the adverse effects bringing by the stiffness rapidly changing in piles shoring andgravity cement-soil wall. Some measures such as pit reinforcement and the crown beamstiffness improvement are used to further improve the deformation of the pit. As toreinforcement in soft soil areas, finite element simulation shows when the pit reinforcementdepth is2/3of the pit depth and the width is1/2of pit depth the reinforcement has a good cost-effective.