Recommendation for numerical modelling of unreinforced and reinforced masonry shear wall construction

Abstract

This study presents the results of an experimental and numerical investigation into the behaviour of reinforced and unreinforced masonry shear walls constructed of infill/unfilled concrete blockwork walls. Numerical models [stiffness based] were postulated, and used to simulate the structural behaviour of masonry shear walls. An experimental program was carried out and involved the testing of four concrete blockwork walls. All four specimens had the same overall dimension 1380x1060x230mm. One of the walls was reinforced with T16mm diameter vertical bars, another with T12mm diameter vertical bars, another had its voids filled with C20 concrete and the forth was unfilled. The walls were tested under partial vertical load simultaneously with horizontal load, to represent lateral loading of the building. From the tests performed it was observed that when the walls were subject to both horizontal and vertical loads, shear lines developed. Eight LVDT's were attached to the walls to measure the deflection and graphs were drawn. Steel and concrete computer models were designed using a suitable stiffness based computer program in order to relate the three different materials of the shear walls. These models had the overall dimensions similar to the masonry test walls. The top most deflection was taken into consideration and it was used in order to find the diameter of the tensile rod required in a steel triangulated structure in order to sustain the same deflection as that present in the masonry wall tested in the laboratory. Furthermore the masonry wall was compared to a concrete model in which the frame stiffness was varied to match the observed lateral displacements of the test walls.