A new seismic isolation system,namely the prestress rubber isolator(PRI,Chinese patent application number:200910174415x),is introduced.The basic principle of this new isolator is: making all or part of vertical deformation of isolator be finished in advance by exerting a longitudinal pre-compressional stress on the rubber isolator with flexible cables, the prestress tension cables become loose because of unloading after the exerting of superstructure loads,and the loose cables can limit the horizontal displacement and resist the tension of isolator. The calculation formula of horizontal stiffness of isolator is derivated,and the mechanical properties are researched. The research results show that:besides the horizontal isolating property of common rubber isolators,the prestress rubber isolator has also properties of reducing vertical deformation, limiting horizontal displacement and resisting tension.Moreover,the prestress isolator has also a certain vertical isolating affect because of the improve of rubber thickness.

As an effective reinforce method, the root pile was widely used in the base of buildings for reinforcing. In this paper, the feasibility of application for the root pile to reinforce high embankment is analysed, its stability design and calculation is discussed, and its construction technology is studied. Taking the Peking-Kowloon line K2155+700~+980 as an example, the reinforcement effect is assessed. The research result shows that it is feasible to reinforce high embankment with root pile.

To understand the higher modal effect on the accuracy of pushover analysis for shear wall structure, the influence of damage on the vibration characteristics of shear-wall structures is investigated. Employing the continuum technique, the shift of modal shapes and periods for the first three modes is obtained when the plastic zone exists in the bottom of the shear wall. It can be conclude that plastic zone may enhance the higher modal effect when the internal force responses of shear walls are considered. The higher modal contribution can not be neglected when computing the nonlinear earthquake responses of shear wall structures.

A simplified 3D multi-degree-of-freedom (MDOF) model for estimation of seismic response of reinforced concrete wall-frame structures with uniform stiffness along the height are proposed in this paper. This model is aimed at reducing the computation demand in the nonlinear response history analysis (RHA). By employing the continuum technique for the structure and adopting the bilinear hysteretic model for material properties, the procedure for the development of a simplified MDOF model, called continuum MDOF model is developed. The proposed continuum MDOF model is shown to provide a simple and efficient for computation of nonlinear response of tall wall-frame structures.

In this paper, a hybrid control system of the energy dissipation and isolation of flexible pile(EDIPF) is proposed, the dynamic analysis model of system is established, and its vibration and control equations are derived. Taking a typical flexible pile base-isolated structure for example, the isolation performance, control effect and main control parameters are studied. The results show that: the isolation and energy dissipation system of flexible pile can effectively reduce the seismic responses of structure, and to apply active control to this system can reduce the possibility of collision between pile and wall of pile hole. At the same time, the vertical loads and the stiffness of superstructure and piles have a significant influence on the control effect of structures.