Numerical Simulation And Optimization Analysis Of Pile Anchor Supporting Structure In Deep Foundation Pit Based On FLAC3D

Among the many supporting forms of deep foundation pits,the pile-anchor supporting structure has the characteristics of high safety,low cost,no occupation of foundation pit space and convenient construction,and is widely used in deep foundation pit engineering.However,Pile anchor protection structures also have many problems in design and construction.To ensure the safety and stability of pit construction and to maximize the avoidance of cost waste,further research is needed on the optimal design of the pile-anchor supporting structure.Taking an anchor pit in Handan City as an example,we will introduce the configuration and mechanism of the anchor support structure of the pile,build a support structure model of the base pit 5-5 area using FLAC 3D software,and perform different stages.The pit was excavated.The foundation.The horizontal displacement,vertical displacement,and axial force sum depth pit deformation of the load structure were analyzed,and the specific parameters of the anchor were simulated and optimized using the orthogonal test method.The maximum value was obtained.The research shows that:(1)31,6 mm is a deep pit at a position of 1 / 13 th of the pit depth.With the increase of depth,the amount of displacement generated from the side wall is constantly improved,and the maximum horizontal displacement is 13 of the pit depth.It is close to 1 / 13 th.The maximum horizontal displacement of the support pile is 26.7 mm and is maintained at the top of the pile.The deep-level displacement of the pile is gradually decreasing,and the rate of decrease of the displacement value is also constantly decreasing.(2)As the pile diameter increased,the horizontal displacement of the support pile gradually decreased.However,when the pile diameter exceeds a certain effective value,the horizontal displacement of the pile becomes slower,and at this time,if the pile diameter is blindly increased,the load structure is not significantly affected.Therefore,on the premise that the stability of the support structure is satisfied,piles with the smallest diameter possible were selected.(3)Through orthogonal test analysis of the various parameters of the pile-anchor supporting structure,it is concluded that the supporting pile diameter is the most sensitive to the supporting structure,and the order of other influencing factors is anchor cable inclination>supporting pile spacing>anchor cable advance Stress>vertical spacing of anchor cables.After simulation verification,when the prestress of the anchor cable in the original plan becomes 500 k N,the inclination angle becomes 13°,and the vertical distance between the anchor cables becomes 2.3m,the maximum horizontal displacement of the support pile is 24.5 mm,2.2 mm smaller than the maximum horizontal displacement of the original design,with a relative index of refraction of 8.24%.Optimized the design parameters of the pile anchor protection structure.