A Nonlinear Seismic Response Study Of Structure On Special Site

With quickly economic development, Tianjin has established program to exploit Haihe riversides. I n the program, buildings and underground engineering will be developed. Underground engineering and river will influence the dynamic characteristics of the nearby building, it is important both in theory and engineering to study that, so this paper will research the following problems.(1) This paper chooses nonlinear constitutive models of soil and building, derivates finite-element matrixes of soil, building and fluid, sets up the integral finite- element interaction model on special site, finds dynamic time history analysis method. Through calculating, ascertains finite-element grid size. Implements the viscoelastic boundary and consider gravity in ANSYS.(2) By studying the effect of river and soft or hard sandwich to site, it can be shown that ground earthquake response increases around river, And the deeper the river is, the more obvious that is. Soft sandwich makes ground displacement increase, shearing strength reduced, and site displacement changes abruptly in that place. Hard sandwich affects ground response little.(3) Under seismic excitation, river will affect the reaction of interactive system. When the structure closes river, the movement and swing of superstructure increase obviously. For nonlinear system, the superstructure takes place irreclaimable excursion to the river, the excursion is more obvious on the site having soft sandwich. Superstructure with shallow foundation excurses more than that with deep foundation, the excursion may make superstructure dissymmetrical force.(4) When tunnel is under building, the wider tunnel is, the bigger building move. When the structure closes river, for the structure with shallow foundation, which may take place irreclaimable excursion to the no-tunnel side, which will cause loading distribution asymmetry in the structure, but for the structure with deep foundation, the phenomena is not obvious.(5) When analyze fact engineering on special site, in order to reduce calculating workload, Two steps method branched inertia coupling is used, The results show which can combine with popular structure design software well, and supply available approach for engineering design.