The Structural Impact Analysis Of Double-Row Pile Of A Large Foundation

With the emerging of high-rise and super high-rise buildings,the depth and area of the foundation pit excavation is increasing.Increasing tensions in the urban land situation,the large foundation pit excavation was bound to affect the road line and adjacent buildings around.Retaining structure with double-row piles as a relatively new type of supporting system,with high resistance to lateral stiffness.In the case of foundation pit depth is not very deep;It works well,cost lower then brace retaining structure with piles and don’t affect the cycle,etc.Due to the complexity of the system of double-row piles and numbers of factors affecting the supporting effect.The calculation mode of stress of retaining structure with double-row piles is still constantly improve Based on the foundation pit engineering command center in XiaMen,the change of parameters of double row pile retaining structure system for supporting effect was system studied in this paper by using FLAC3 D finite element software.And using the orthogonal analysis method analysed the influence of before and after excavation of the foundation pit nearby on the double row pile system without beam.This provided a reference for the future of double row pile retaining engineering design and construction.The simulation results show that:(1)Pile row spacing and row pile embedded depth had certain influence on the displacement,the influence of pile spacing and pile stiffness on displacement is small.Row spacing was an important parameter to cause double row pile support structure deformation.The increase of row spacing,pile spacing,the front row pile embedded depth and the pile stiffness will lead to the front and rear row of pile bending moment increased;but the increase of rear pile embedded depth leaded to decrease the bending moment of both piles.(2)Inter row soil reinforcement for the double row pile displacement control can play a good role.Within pile length,The displacement of retaining structure is gradually reduced with the increase of the depth of reinforcement.Beyond the pile length,the effect of the depth of the reinforcement is not significant.The effect of soil reinforcement is the best When the soil reinforcement width is full of Row spacing.(3)The influence of excavation of adjacent foundation pit on supporting deformation of first excavation foundation pit,from high to low : the depth of the first excavation pit,the depth of after excavation pit,the width of after excavation pit,the distance between the foundation pit.The influence of excavation of adjacent foundation pit on supporting deformation of after excavation foundation pit,from high to low : the depth of after excavation pit,the distance between the foundation pit,the width of after excavation pit,the depth of the first excavation pit.(4)The deep foundation pit,which is supported by steel support,had a greatly influenced on the relatively shallow foundation pit adjacent to it.This cause a larger lateral deformation of the supporting structure.