Interaction Analysis Of Ecological Composite Wall Structure-Raft Foundation-loess

Ecological composite wall structure is an environment-friendly, insulating andenergysaving new type of building structure system; it has advatanges such as dampingeffect and fast construction. The parts of the pilot projects have been completed; thisstructure has broad application prospects.Currently, for engineering applications of thisstructural system, structure designs are carried out by rigid foundation hypotheseswhich not take into account the structure-foundation-soil interaction. This assumption isnot able to reflect the actual force characteristics of the structure, which makes designresults conservative. In order to make the design of ecological composite wall structuremore scientific and reasonable, in this paper, considering pre-test results of researchgroup, choose the method of combining theoretical analysis and numerical simulation.Under the condition of horizontal loads and vertical loads, mainly analyzes the impactof the law which is about ecological composite wall structure-raft foundation-loessinteraction structure of the force and deformation properties. The main work andconclusions are as follows:(1) Combined with pre-test research of research group, based on the uniquecomposite wall structure and mechanics of composite materials, composite wall elasticstage model-Composite Materials plate model is built up; and the wall elastic modulus,shear modulus and Poisson’s ratio practical formula is derived. According to themechanical characteristics of the ecological composite wall structure, the upperstructure is simplified as frame-composite equivalent elastic plate model. And thendiscuss the application of frame-composite equivalent elastic plate model for numericalanalysis of ecological composite wall structure-raft foundation-loess interaction.(2) Combined with an engineering instance of ecological composite wall structural,a series of soil samples index test of physical and mechanical properties were carriedout in the selected engineering venues, which are to gain the parameters of the modelsoil such as ρ, ω and Esetc. By conventional triaxial compression test, obtain thefoundation soil mechanics parameters c and φ; and then determine parameters E and μ.Elastic-plastic Drucker-Prager model is selected to simulate the foundation soil.(3) Ecological composite wall structure-raft-loess foundation interactive numericalmodel and the corresponding rigid foundation model are built up by using the finiteelement software ABAQUS; and then compare and analyze the difference of thehorizontal displacement of the upper structure and the frame column of internal force between interaction method and an ordinary method. The results showed that: Whentaking into account the effect of interaction, the non-negligible secondary stress wouldemerge in the ecological composite wall structure; the horizontal displacement of toplayer for the upper structural also increased significantly and the amplification,comparing with non-interaction, is34.4%. And then analyze the impact of the horizontalload on internal force and subsidence of raft and subgrade reactionand for consideringinteraction of the structural system. And then analyze the impact of the horizontal loadon internal force and subsidence of raft and subgrade reactionand for consideringinteraction of the structural system. The results show that: taking into account thehorizontal loads, the internal forces of foundation and subgrade reactionand wouldchanges significantly; the differential settlement of the foundation would increase,which is lead to increase of secondary stress in the upper structure.(4) Change the critical parameters of ecological composite wall structure-raft-soilsystem considering interaction for in-depth numerical analysis. Obtain the law of effecton the upper structure and raft of internal forces, foundation settlement and subgradereactionand when alter key factors such as the thickness and strength grade concrete ofraft and foundation soil deformation modulus etc., which would provide reference onthe optimal design and enaction of code for ecological composite wall structure.