Dynamic response of an interlocking plastic-block wall with opening

Abstract

The failure of unreinforced masonry structures (e.g., a collapse) because of their vulnerability to earthquake action poses an actual threat to human life. Researchers have investigated many mortar-free interlocking techniques. But the mass of interlocking blocks is a point of concern. The interlocking plastic-blocks are lighter in weight, possibly causing a lesser lateral force during the strong ground motions. However, the dynamic response of such structures is unknown. Therefore, the objective of this research is to examine the dynamic behavior of the scaled down model of the interlocking plastic-block wall having window in comparison with a model of an unreinforced masonry wall with the same elevation dimensions. Two dynamic tests, i.e., snapback and harmonic loading, are conducted in the out-of-plane direction. From the snapback test, the fundamental dynamic characteristics i.e., fundamental frequencies and damping ratios are experimentally determined. For learnt frequencies from snapback tests, three harmonic loadings are applied one by one using a locally developed unidirectional shake table. Acceleration time and displacement time histories are used to study the behavior of walls. Base shear displacement curves are used to determine energy absorption. Empirical equations are established by taking into consideration the input loading parameters, wall height, and geometry of interlocking blocks. It is found that the interlocking plastic-block wall is more resistant to unidirectional lateral loading when compared with a masonry wall.