Experimental and numerical study of the spring-asphalt 3D isolation structures under multi-component ground motions

A low-cost spring-asphalt bearing for the 3D seismic base isolation of low-rise residences is presented in this paper. Its dynamic response under horizontal, vertical and rocking ground motions is studied by shaking table test. Different types of excitations such as horizontal excitation only, horizontal and vertical excitation, horizontal, vertical and rocking excitations with different peak ground accelerations are input. A numerical model is developed to further study the dynamic characteristics of buildings with spring-asphalt 3D isolation bearing under multi component ground motions. Frequency domain and time domain analysis are conducted to research dynamic responses of the model. The function of asphalt is also researched by contrast experiments. Research results show that the 3D isolation bearing could efficiently reduce horizontal and vertical acceleration response of upper structures. Furthermore, asphalt makes the structure possess good energy dissipation capability. In addition, the asphalt could provide considerable damping and reduce the displacement while does not add so much stiffness.