Low cost damping scheme for low to medium rise buildings using rubber soil mixtures

Abstract

This study proposes to develop a low cost damping scheme using soil and waste tyre crumb mixture for low to moderate rise buildings. The proposed study consists of two parts, first characterizing soil and waste tyre mixtures and finding out the optimal size of tyre crumbs. The second part is to design the isolation system for low to moderate rise buildings and determine optimum dimension of the system. In the first part, a series of Unconsolidated Undrained triaxial test and large scale direct shear test have been carried out to select the optimum size of tyre crumbs from seven different crumb sizes. The Rubber Soil Mixtures (RSM) sample that provides higher shear strength, energy absorption capacity and stiffness is considered as the optimal size and further used in numerical simulations. In the second part, to analyze the damping effect of RSM, extensive numerical simulations have been carried out on the soil-foundation-structure system with varying thickness of RSM around isolated footing, varying percentage of rubber in RSM and input time history. The reduction in shaking level in terms of acceleration and inter storey drift, at different floor level with the use of RSM can be reduced by 40 to 50%.