Seismic Respondes Analysis Of Space Latticed Structure Considering Soil-structure Interaction

Space latticed structures are widely used in civil engineering with the advantagesof light weight, reasonable force, large space, easy construction and various styles. Inorder to further investigate the antiseismic performance of space latticed structure,with the consideration of soil-structure interaction (SSI), this dissertation analyses theseismic responses of space truss and double layers cylinder latticed shell supported bycolumns. The influence on seismic responses of space latticed structure consideringSSI can be obtained and the main research works are as follows.(1) Equivalent linearization model is adopted to simulate soil nonlinearity forspace latticed structure considering SSI and equivalent linearization method isrealized by re-development of FEM program ABAQUS. The results of seismicanalyses for three-dimensional (3D) site soil show that the equivalent linearizationmethod is reasonable and reliable.(2) The method for synthesizing artificial ground motion compatible with designresponse spectrum of “code for seismic design of buildings GB50011-2010” based onphase cosine partitions is presented and realized by programming to eliminate thenon-convergence of error occurring in amplitude adjustment. The adjustment methodbased on phase cosine partitions can eliminate the non-convergence of error andartificial ground motion applied for SSI analysis of space latticed structure can beobtained.(3)3D finite element models of space latticed structure based on theconsideration of SSI are established. Under conditions of SSI and assumption of rigidfoundation, dynamic characteristics and nonlinear time-history analysis of seismicresponse are analysed respectively and then dynamic characteristics and seismicresponses results of space truss and double layers cylinder latticed shell can beobtained. The results show that: the dynamic characteristics of space latticed structureconsidering SSI are significantly different from the cases under rigid foundationassumption. When considering SSI, the natural vibration periods of space latticedstructure increase and horizontal vibration is basic vibration mode for latticedstructure supported by columns. When horizontal ground motion is inputted alongspan direction, with the consideration of SSI, the displacements of space latticedstructure increase; for space truss supported by columns, axial force of most membersdecrease and axial force of members near columns increase; for double layers cylinder latticed shell supported by columns, axial force of all member decrease. When3Dorthogonal ground motions are inputted, for space truss supported by columns withthe consideration of SSI, horizontal displacements increase and vertical displacementsdecrease compared with rigid foundation assumption; for Site-class Ⅱor Ⅲ,compared with rigid foundation assumption, axial force of members considering SSIchange no significantly; for Site-class Ⅳ, compared with rigid foundation assumption,axial force of members considering SSI decrease.