Analysis Of Tall Building Structures Concerning About Ground And Floor Deformations

The co-work of superstructure with subgrade and foundation has been the concern of many people in charge of tall buildings analyzing, under certain conditions the influence of the grounds deformation to the superstructure should be considered. In the structure of the tall buildings, the floors not only endure the floor loads but also share the horizontal loads between each anti-lateral force unit, in some special structures the floors deformation should be considered, otherwise there will be huge error. Considering grounds and floors deformation can reflect actual load the building structure are bearing.The influences of grounds and floors deformation on the cooperative, the second order analysis and the dynamic property of tall building structures are studied in this paper. Based on the continuum approach, Each lateral resisting structure is regarded as Timshenko beam placed vertically, floors are regarded as beams with shear type deformation placed horizontally, Each foundation is regarded as spring support to the base of the resisting structure which has horizontal migration and Vertical rotation deformation, the uniform parallel Timshenko beams model of the tall building structures are founded considering grounds and floors deformation.Form the Energy variational principle, introducing the dual variable of the former through the original variable, which lead the question from the Lagrange system to the Hamilton dual system, then derives the Hamilton dual equation of the corresponding questions. The precise integration method of two end boundary conditions is adopted to realize the high-precision numerical solution of the question by means of computer program with Matlab. The influences of grounds and floors deformation on the cooperative, the second order analysis and the dynamic property of tall buildings are analyzed through typical examples. The research indicates: The change of inner force is most obvious in the base of the resisting structure, when dynamic analysis it increased some vibration mode which correspondingly grounds and floors deformation. The whole numerical algorithm have the merits of stability, high precision and fast convergence. It provide a new method for research this kind of engineering problems, which has some reference values.