Study On Pile And Beam Underpinning Technology In The Foundation Reinforcement

When the foundation bearing capacity can not meet the architectural design requirements or foundation settlement deformation is too large,it normally should be treated to improve the foundation performance,and the pile foundation may be chosen.The conventional method of designing the pile foundation generally does not consider the sharing of the load between the soils of the pile,only considering the bearing capacity of the pile.This design is too conservative.Therefore,in the design of the pile foundation,the bearing capacity of the soil should be taken into full consideration Using the pile and soil interaction theory knowledge to reduce engineering costs.However,there is not a complete set of theoretical and computational methods.Therefore,in order to meet the needs of practical engineering,it is necessary to further study the common problem of pile and soil.In this article,Zhangjiakou residential area in the occurrence of uneven settlement need to carry out the basic underpinning reinforcement as the background,first reviewed some of the past underpinning reinforcement technology and pile and soil interaction analysis theory.The situation at home and abroad made in-depth and meticulous research.On the basis of the above,based on the theory of soil elastic-plasticity,the basic theory of nonlinear finite element analysis and the principle of pile-soil interaction,the advantage of large-scale finite element software ANSYS is used to establish an effective common action model.Study the influence of the elastic modulus,the pile diameter and the pile length on the pile load sharing percentage and the settlement of the pile foundation under the three conditions of loading the cushion layer and the secondary loading(using the life and death unit method).The results show that with the increase of the elastic modulus of the pile,the settlement of the pile is small and the percentage of the load shared by the pile is increased,but the effect is not significant.The increase of pile length and pile diameter can improve the bearing capacity of the pile,and the effect of increasing pile diameter is more significant than increasing pile length for improving pile bearing capacity Therefore,in the design of pile foundation,it is of great engineering significance to reasonably determine pile length and pile diameter to improve pile bearing capacity and control settlement.