Study On Settlement Calculation Of Shallow Foundations Of Multi-storey Buildings By3D Nonlinear Finite Element Method

Each structure is composed by three parts, which are superstructure, foundationand subsoil. At present, though project planners have been widely realized that ittake the three parts as a whole and use the theory of interaction for calculation andanalysis, for quite some time, due to the restriction of the calculation means and thecombined action theory of calculation methods still is not perfect, the superstructurefoundation and subsoil are usually hard or unable to consider the combined actionbetween the three parts and thus they calculated and designed separately in practicalengineering design, without considering the effects generated by their respectivestiffness and the deformation coordination conditions between them. This calculatedresult may make building foundation appearing larger uneven settlement, which isone of the main reasons that lead upper structure to produce biggish secondary stressthat cause many a houses appear cracks or even compromise safety. Therefore in thehigh-speed development background of computer and finite element numericalcalculation technology, this paper use3D nonlinear finite element method to analysisthe multistory buildings of settlement and deformation. The advantage of thismethod is able to consider the three as a whole to overall analysis and reveal thesettlement quantity size that foundation will possible come forth and the unevensettlement deformation and the secondary stress the upper structure may emergence,and can adjustment foundation design dimensions or take corresponding measureson the upper structure to make the building’s foundation settlement evenly and avoidthe harm caused by uneven settlement. This paper’s work is of great theoretical andrealistic significance in promoting applications of the finite element method onhousing construction settlement calculations, its main research content as follows:Firstly, this paper briefly summarizes the research situation of interaction duringupper structure, foundation and subsoil and some existing analysis methodsproposed by predecessors, and emphatically introduced the current extensively usedsubstructure method. Secondly, using the large-scale non-linear finite element ABAQUS establishes athree layers masonry structure house model(3D) which foundation is bar foundation,the subsoil adopts the Duncan-chang nonlinear elastic model which can welldescribe the hardened soil constitutive relation, using Duncan-Chang model’s usermaterials subroutines which is already developed in ABAQUS software platformnumerical simulation, at the same time the subsoil’s soil constitutive relation is alsoassumed as linear elastic model and Mohr-coulomb ideal elastic-plastic model andthen do some similar analysis to compare with Duncan-zhang model analysisresults, it acquires the three parts settlement deformation disciplinarian and the upperstructural internal force distribution under the different soil constitutive relations,and according to the maximum principal stress analysis, attains tensile damage areathe wall may produce, and puts forward the measures to reduce the unevensettlement at the end.Thirdly, a natural foundation extended basic three-layer frame structure house isanalyzed by3D finite element method. The extended basic is designed based oncurrent criterion. By extracting post-processing results, it can obtain the frame’sbeam and column internal force. and it can readjust foundation design size accordingto the settlement quantity, and then numerical simulation analysis is carried out againand finally can make buildings’ everywhere settlement uniform, thus this makeshallow foundation design more scientifically and rationally, and reduce this kind ofarchitecture based on traditional design excessive uneven settlement which can causewalls and beams and column crack problem, etc, and improve multi-storey buildingof natural shallow foundation design calculation level.