Study On The Support System Of Deep Foundation Piles And Research On Topology Optimization

As the size of the city continues to expand,high-rise urban structures are also emerging,followed by extensive excavation of deep foundation pits.Due to its strong adaptability,small impact on the surrounding environment and small deformation of foundation pit,the support system of piled piles has been widely used in foundation pit support engineering.As the foundation pit supporting project in many cases have adopted a more conservative design method,if the rational detail design can be optimized to meet the constraints of the premise to maximize the material savings,thereby reducing the cost of support to improve economic efficiency the goal of.Based on a concrete example of pit-supporting foundation pit project,based on the introduction of the design method of piled piles support and earth pressure theory,an incremental method and an equivalent transformation method to meet the displacement coordination are selected to study the engineering examples.The main results are as follows:(1)The stability calculation and internal force displacement analysis of foundation pit are carried out by using the calculation software of Lizheng deep foundation pit.The checking results show that the supporting structure is safe and reliable.The excavation depth increases and increases,the most horizontal position of displacement gradually moves down to the excavation surface,and the second inner support plays an important role in controlling displacement of pile.(2)Numerical simulation analysis of the supporting pile and the internal support by the finite element software ANSYS.Compared with the calculation and analysis of the structural mechanics solver,the displacement curves of the supporting pile almost coincide.The topological optimization parameters of the support force and the equivalent stiffness coefficient The similarity is more than 90%,which verifies the reliability of the finite element program.The equivalent load of the first inner support topology optimization parameter is obtained,and the equivalent stiffness coefficients are 208153 N and 3198646 N / m,respectively.The equivalent load of the second inner support topology optimization parameter is equivalent to 858266 N and 1.02E8 N / m.(3)The influence of pile diameter and pile length on topological optimization parameters,the supportive force and equivalent stiffness coefficient increase with the increase of pile diameter in single-layer internal support model.With the increase of pile length But decreases,the equivalent stiffness coefficient increases with the increase of pile length.(4)Three kinds of internal support topology optimization forms are obtained by using the equivalent load of topological optimization parameters and equivalent stiffness coefficient respectively,and three kinds of internal support solutions are obtained.Three kinds of internal support values are calculated by numericalsimulation and three internal support values are calculated.Using Java Script program calculation and analysis of the program three 68.29 thousand for the cost of the best program.(5)To explore the application of topology optimization in irregular foundation pit engineering,using the first internal support topology optimization parameter optimization analysis,two kinds of internal support schemes have been formed,and each internal force value has been put into Java Script program to get the solution II of70.358 thousand Yuan for the best cost program.