Finite Element Simulation Of Pile Foundation Replacement And Analysis Of Application Examples

With the development of the world economy nowadays,traffic congestion has become an urgent problem to be solved.The widespread use of pile foundation structures is one of the effective ways to alleviate current traffic pressure and population pressure.The pile foundation has the advantages of high bearing capacity and good stability.However,with the large-scale use of deep pile foundation,the problem of geological settlement and excessive pile foundation depth has become increasingly prominent.Therefore,the pile foundation underpinning technology proposes a more scientific method to solve the problem of foundation reinforcement of existing buildings,the construction of underground works under the existing buildings and the impact of new construction projects on the safety of existing buildings.At the same time,the numerical simulation method of pile foundation underpinning technology is explored,and the numerical simulation data and actual monitoring data are compared to guide the engineering construction,which has important scientific research value and practical engineering significance.Based on the above background,the main research objective of this paper is to analyze the influence of the original abutment and the underpinning structure in the pile foundation underpinning process by finite element method.By comparing the numerical simulation data with the field measured data,it is analyzed whether the numerical model is reliable and capable.No as a reference for the prediction of subsequent construction.It mainly includes the following research contents:(1)Based on the finite element method,the model is built separately for the pile foundation underpinning process,and the model calculation of the preloading process of the new underpinning pile is carried out,and the internal force variation and bearing capacity of the new pile in this process are analyzed;(2)Study the influence of the pre-lifting process on the original abutment and the underpinning structure,calculate and analyze the stability of the underpinning structure;(3)Simulate the internal force variation of the post-concrete concrete after pouring,analyze the abutment;(4)Taking the pile foundation underpinning project of Zhengzhou Metro Line 5 as an example,the numerical simulation and the measured results of the field survey were compared and analyzed.The following research results are obtained:(1)Through the analysis of numerical simulation and theoretical calculation values,the axial force difference between the two is relatively small during the preloading process,and the underpinning structure is safe and reliable;(2)The pre-lifting process is on the original abutment and The influence of the underpinning structure is small and does not affect the normal state;(3)After the pouring concrete is poured,the settlement of the abutment,the deflection of the supporting beam and the axial force and displacement values of the supporting piles are within the allowable range.It is negligible relative to the whole structure;(4)The numerical simulation data is different from the field measured data,but the trend of the settlement curve is similar,the characteristics are the same,and the numerical model is more reliable.The model can be used as a reference to predict the subsequent construction.In this paper,the combination of pile foundation underpinning technology and finite element numerical simulation method has important scientific research value and practical significance.