Study On Coefficients Of Pile Group Interaction And Settlement Calculation Method On Finite Element Simulation

Traditional high-speed railroad bridges crossing big rivers and rivers,overpasses built by freeways on highways,viaducts and overpasses built in cities to ease traffic pressure,large-span bridges across the Yangtze and Yellow Rivers,and large bays and straits.The bridge has been completed,which further increases the requirements for the bearing capacity,stability and deformability of the foundation project.Pile group has been widely adopted because of its advantages such as high bearing capacity,good stability and small deformation.The rigid pile composite foundation is one of the large group pile foundations and is widely used in post-construction settlement control of high-speed railway subgrade in China.At this stage,the composite modulus method and solid foundation method for group pile foundation settlement do not fully consider the influence of the pile-pile interaction relationship,making the calculation method of group pile settlement analysis lack rationality,and the calculation result is different from the actual settlement value.Big.The PS curve data of static load test are more abundant.On the basis of using a single pile static load test to evaluate the bearing capacity of a single pile,the static load test data is further excavated,and the settlement of the pile group foundation is predicted to be larger by the static load test of a single pile.research value.Based on the study of the interaction coefficient of pile,the formula of pile group settlement is obtained by regression fitting.The main research contents are as follows:(1)This paper briefly introduces the domestic and foreign related literatures and materials,gives a brief overview of the development and classification of pile foundation,analyzes the development and current situation of the calculation method of pile group settlement at home and abroad,summarizes the main analytical methods,The study of the calculation method of foundation settlement is convenient.(2)The P-S curve derived from the static load test of a single pile contains a rich interaction between the soil layer and the pile.First,the curve is fitted with hyperbola so that the load curve of a single pile can be studied later.Secondly,using the existing single pile static load test data for back analysis,the elastic parameters of the soil layer and the parameters of the pile-soil contact surface are obtained,and a three-dimensional force model is established using the finite element software Abaqus,and the results of the model operation and analysis are compared.Comparison of the actual values of PS curves to verify the rationality of back analysis of parameters.(3)Based on the existing pile-soil model,the soils in the pile-pile calculation are simplified.(4)The finite element software Abaqus was used to establish the two-pile model.Theeffect of parameters such as the distance ratio of the pile,the ratio of the length to the diameter,the elastic modulus ratio of the pile and soil on the pile-pile interaction coefficient was analyzed,the data were subjected to regression analysis,and the calculation interaction was obtained.The empirical formula of the coefficient.And further verify the correctness of this experience.The regression formula is applied to the settlement calculation of group pile foundation,and then the formula for the settlement of group pile foundation is calculated.(5)Based on the background of the Beijing-Tianjin Intercity Railway Wuqing section,the pile foundation is analyzed,and the design theory and construction technology of pile foundation calculation are reviewed in the third chapter.