Seismic out‐of‐plane behavior of unreinforced masonry walls

Abstract

AbstractUnreinforced masonry (URM) is one of the most used construction types in the world. In addition to the design for static loads, URM walls must also be designed for earthquake scenarios. In this load case, the out‐of‐plane loads (transverse to the plane) often have a significant impact on the load‐bearing capacity. In most practical applications, simplified methods are used to determine the out‐of‐plane capacity of URM walls. The estimations of these simplified models are often inaccurate since essential parameters are neglected. To determine out‐of‐plane capacity realistically, parameters such as vertical stiffness of the support, geometry, constraints, vertical loads, and dynamic effects must be taken into account. At the University of Kaiserslautern, shaking‐table tests with different conditions of upper support are performed. Real earthquake time histories are applied and increased until collapse of the wall. For numerical analyses of the deformation response of the wall, nonlinear single‐degree‐of‐freedom systems are developed and calibrated. In addition, results from simplified analysis models are compared with experimentally determined maximum acceptable earthquake accelerations. The comparison shows that the out‐of‐plane capacity is much higher than predicted by simplified models. The experimental, analytical, and numerical investigations on URM walls will be used to develop a simple and practical applicable engineering model in the next phase of the project.