Parametric Study on Natural Rubber based Low-Cost Base Isolation Technique for Masonry Buildings

In developing countries, masonry is widely used for construction due to its availability and low cost. The masonry buildings are vulnerable to moderate and severe earthquakes due to their brittle nature. The use of base isolation techniques for masonry building has seen an increasing trend in the past two decades. However, existing isolation techniques are uneconomical, requiring skilled labor and specialized manufacturing processes. Hence, the present study focuses on developing a novel low-cost base isolation technique using locally available natural rubber. In the proposed technique, unbonded rubber is spread beneath the plinth level of the wall. A parametric study has been conducted numerically to evaluate the isolation efficiency of the rubber with varying thicknesses and lengths. This study also involves different sizes and thicknesses of the rubber placed intermittently with gaps. ABAQUS CAE V6.13 is used for simulating the behavior of natural rubber and masonry building. The properties of the rubber and its numerical modeling has been validated with the existing literature and further used for parametric study. From the parametric study, suitable dimensions and thickness of the rubber are obtained to increase the performance of the proposed isolation technique without sliding. The identified rubber dimensions placed intermittently with gaps have led to increased vertical stiffness and damping with required low horizontal stiffness compared to rubber spread throughout the plinth.