Analysis Of Behavior And Displacement Of Pile-Anchor Bracing System

Deep foundation pit engineering is an ancient traditional subject of underground foundation engineering, and it is also a complex synthetic structural difficult problem. It involves not only typical strength, stabilization and deformation, but also the co-effect of soil and support structure. In recent years, along with a great deal of high buildings set up lately and the city underground space of development, make the problem of the deep pit of foundation excavation and support rise to a very important position. Anchor piles bracing structure is a new kind of supporting structure used support structure used wildly in deep foundation pits. But its design calculation theory is not perfect, and there are many problem when designing and computing structure. The phenomenon of design theory lagging behind the practical application appeared.But, only limited research work has been done for the calculation of the pile deformation during the construction except that on the Finite Element Method. Aiming at existent problems in design calculation of the anchor piles bracing structure, the horizontal displacement of the supporting structure are studied in this paper. Main contributions are listed below:1. the design and calculation of the bracing structure in deep excavation do not consider the affect of work course in the code for building foundation (GB 5007-2002), so the calculation result is not similar with the reality. Through calculating a case with the formula of excavation layer by layer, this paper get the horizontal displacement of the anchor piles bracing structure.2.Based on the empirical formula of ground settlement, the ground displacement of deep foundation is caused by excavation and precipitation. Through the superimposition of the displacements in the both aspects, we can get the result of the ground settlement. Many building foundation are pile foundation in the city of lanzhou, so we analysis the settlement of building with pile foundation. According to these cases, the formula are derived to calculate the settlement of building and the ground settlement.3.Takeing use of both 3-D element group and rebar element group in the nonlinear finite element software ADINA, this paper simulate a case. Through the Post-Processing of ADINA, we can obtain the band plot of deformation of the deep foundation pit along with the excavation layer by layer. Comparing the results with the obtained result by above method, we get that the method which is mentioned above is rational and reasonable.