Calculation And Optimization Of Anchor Supporting Pile Of Deep Excavation

With a great deal of tall buildings and substructures constructed,the excavations are becoming more and more.The design and construction of the excavation are becoming more and more difficult.How ,in the guaranteeing the security of foundation pit,reduces the protecting structure as far as possible theconstruction cost,has become a question that foundation pit protecting structure designer must solve.The traditional earth pressure theory is based on the assumption that when the soil body arrives the limiting condition,the sliding surface is straight line sliding surface.But when the soil body is at the limiting equilibrium condition ,the actual sliding surface is the curve sliding surface.On the basis of introducing traditional earth pressure theory,this paper introduces the Prandle sliding surface earth pressure formula which is inferred based on the Prandle sliding surface. Then this paper combines Prandle sliding surface earth pressure formula and Rankine earth pressure formula,respectively with the common calculation method of anchor supporting pile(Which are equivalent beam method,simplex 'm' method and elastic space link department finite element method )Then this paper establishes calculation procedures with Matlab.These procedures are used to calculate engineering example.After establishing a series of calculation modulars combining with the function of optimization of Matlab,this paper does optimization of engineering example .After finishing a series of computations,there are some conclusions to draw :1.The maximum moment that the pile body bears when we combine equivalent beam method with Prandle sliding surface earth pressure formula to calculate are less than what we get when we combine equivalent beam method with Rankine earth pressure formula.2.The maximum positive moment (Which we get when we combine simplex 'm' method with Prandle sliding surface earth pressure formula to calculate) is quite close to the actual value .The maximum negative moment (Which we get when we combine simplex 'm' method with Prandle sliding surface earth pressure formula to calculate) is slightly larger than the actual value.The maximum positive and the maximum negative moment are larger than the actual value when we combine simplex 'm' method with Rankine earth pressure formula to calculate.3.The maximum positive moment that the pile body bears is less than the actual value when we combine Prandle sliding surface earth pressure formula with elastic space link department finite element method to calculate. The maximum positive moment that the pile body bears is larger than the actual value when we combine Rankine earth pressure formula with elastic space link department finite element method to calculate.4.If we use different earth pressure formula in the corresponding optimized goal computation module,we get the different optimized goal computed result when we carry on optimization computation .