Method For Seismic Soil-Structure Interaction Response Analysis Of High-Rise Building

The seismic design method of buildings is based on the rigid groundhypothesis in current code. Although this method is easy to use, with theaccumulation of earthquake damage data and the development of seismicbehavior research on high-rise buildings, the people discover that this kind ofrigid ground hypothesis does not conform to the actual condition in some cases,sometimes is unsafe for the seismic design of buildings. So this paper gives amethod for seismic soil-structure interaction response analysis of high-risebuildings, which provides an analysis measure to further research the influenceon the seismic response and seismic design of high-rise buildings fromsoil-structure interaction.The principle and the essence of soil-structure interaction was introduced,and the existing analysis methods of soil-structure interaction was commented.Then, a practical method for seismic soil-structure interaction response analysisof high-rise building is given. A simplified two-dimension soil-structureinteraction analysis model of high-rise buildings is given on the basis ofconsidering the actual condition and mechanics behaviors of the superstructure,the base and the foundation soil in detail. In this model, the principle ofcoordination work between the frame and shear wall (tube) is considered by usingmatrix displacement method. The superstructure is simplified to two-dimensionframe-shear wall (tube) structure that can simulate flexible and flexible-shearcharacteristic of high-rise buildings. The analysis model of foundation soil is aunit of soil with 'H' high, 'B' wide in the calculated plane, and 't' thick in theout-of-plan direction. The nonlinear characteristic of foundation soil is taken intoaccount by using the E-B constitutive relation model, and the boundary conditionof foundation soil is simulated by adopting viscous-spring artificial boundarycondition. Three analysis models of foundation can been employed according tothe stiffness of foundation. And the contact iteration algorithm is used to simulatethe interaction between the pile, the box and the soil. Through massive trialcalculation, this algorithm contact parameters are suggested. According to thefeature of the method in this paper, three kinds of finite element software whichcan be used in studying the soil-structure interaction of buildings has beencompared. MSC.Marc, a large-scale nonlinear finite element software with betterredevelopment function is chosen as a analytical tool of the method on the basisof evaluating the advantages and disadvantages of the three kinds of software.The model of elements in each part has been selected from existing elements ofMSC.Marc. MSC.Marc is redeveloped so that the E-B constitutive relation modelof multi-layer soil is embedded in MSC.Marc. An example is calculated to verifythe reliability of the redevelopment. Finally, a high-rise building has beenanalyzed as an example by adopting the method, whose analysis results arecompared with those without considering soil-structure interaction. In addition,the influence on the seismic response of high-rise buildings from the pile-soilinteraction is discussed initially. Through the example, some conclusions areobtained, and the validity of the method is proved.