Research On Bearing Capacity And Calculation Method Of Bearing And Anti-sliding Pile In Slope Area

China is in the process of high-speed urbanization.Following the "Western Development",the national strategies of the "Belt and Road" and "new land and sea routes" have been Implementation has been comprehensively promoted.However,the central and western regions are mostly mountains and plateaus.The complex terrain of valleys and valleys has brought great challenges to engineers.The calculation of foundation engineering research in these areas is also one of the urgent problems to be solved.In this context,the pile foundation,as the most common form of foundation for housing construction,bridges and elevated buildings,will inevitably fall on slopes.Due to the natural and special geological environment,the pile foundation is endowed with the dual characteristics of anti-slide and load-bearing piles..The research difficulties of this type of load-bearing drag piles mainly focus on the form of landslide thrust behind the pile,the model construction of the pile-soil interaction,the failure mode of the pile-soil system,the theoretical solution of the pile body response,and the calculation method of the second-order effect of vertical load And the law summary of the response characteristics of the foundation pile.This article focuses on the above aspects,with innovative theoretical methods as the main core,writing programs as the means of implementation,and service engineering design as the ultimate goal.The main research contents are as follows:(1)Sorted out the types of pile foundation response calculation methods under load,and sorted out the most widely used linear elastic foundation reaction method,py curve composite foundation reaction method,including m value,k value and c value,etc.The lateral action model and the vertical action model of pile-soil friction and embedding based on transfer function,experimental testing,etc.were analyzed,and the bearing characteristics of load-bearing resistance sliding piles were analyzed,including the normal use limit state of the foundation pile,the load capacity limit state and the slope Possible failure modes including foundation bearing capacity.(2)The matrix equation calculation method different from the previous power series method and numerical calculation method is derived.Based on the winkler foundation beam,the theoretical calculation of the pile foundation is reduced to a plane problem,and the basic assumptions required to satisfy the mechanical model are proposed.According to each characteristic segment,the deflection differential equation is established,the theoretical analytical solution of each micro-segment of the pile foundation is organized into a matrix calculation formula,and a matrix linear equation system of all piles and all nodes is constructed.Means to solve the second-order effects caused by vertical loads.(3)The matrix equation calculation method deduced in this paper is realized by matlab programming,and all programs are divided into parameter input module,calling program module,main program module of pile response calculation under lateral load and subprogram module of cyclic calculation second-order effect.(4)Three calculation examples of single stratum,multi-stratum flat ground pile,anti-sliding pile and load-bearing anti-sliding pile were used to verify the matrix equation calculation method and the matlab program written.Influencing factors including diameter,etc.are analyzed and the laws are summarized.(5)Carried out a horizontal bearing capacity test of a pile foundation site of a project in Beibei District,Chongqing,and tested and calculated the horizontal resistance coefficient of silty clay mixed with sandstone blocks,integrating existing buildings,highways,railways,ports,and disaster control,etc.Many of the specifications were sorted and discussed,and suggestions were made on key issues such as m value,k value,horizontal resistance coefficient reduction,foundation pile member design,and method for determining the embedded depth of load-bearing resistance sliding pile engineering design.(6)Combined with a project in the western mountainous area of Chongqing,the matrix equation calculation method and matlab program were used to calculate the internal force and displacement of the pile foundation,and the slope support and building foundation design were realized.It has operability and reliability in engineering applications.