A low-cost isolator of scrap tire pads in rural construction: Evaluation of the mechanical properties and numerical assessment of the response control effects

Abstract

When designing seismic isolation buildings in rural construction, the main problem required attention: the isolation bearing relatively high costs. As one type of rural isolator, scrap tire pads (STP) are considered as an effective measure to overcome this problem. However, the abrupt change of vertical stiffness, horizontal equivalent stiffness, and damping ratio of STP would result in the stability problem of the isolated structure. In addition, the factors influencing the vertical stiffness, equivalent stiffness, and damping ratio of STP are geometric parameters, loading conditions, and tire type. For these purposes, a total of 90 STP were designed, and a series of compression and shear tests were conducted. The geometric parameters included the first and second shape factor (S1 and S2). The tire type included the snow tire and all-season tire (ST and AST). Various surface pressure (4, 5 and 6 MPa) and displacement amplitudes were considered. The experimental results showed that the vertical stiffness of STP increased with the increase of the S1, S2 and surface pressure. The tire type, shape factor, surface pressure and displacement amplitudes had a significant effect on the horizontal equivalent stiffness and damping ratio. Finally, based on experimental results, a numerical response was conducted including the fixed-base structure and STP isolated structure under 4 recorded ground motions and 2 simulated waves. The results show that the peak accelerations, inter-story drifts and shear of the STP isolated structure were reduced by 56.64%, 30.00% and 26.61%, respectively, compared with the response of the fixed-base building.