Spatial Correlation of Material Properties and Structural Strength of Masonry in Horizontal Bending

摘要

Spatial variability of material properties might significantly affect the structural performance and reliability of unreinforced masonry (URM) walls. The paper develops a computational method to predict the strength for URM walls subject to one-way horizontal bending considering unit-to-unit spatial variability of the material properties of mortar joints and bricks. In this context, the term unit is being used to describe the location in the wall associated with a single brick and the adjacent mortar joints. In this way, the material properties are assumed to be uniform along the length, height, and thickness of individual bricks but may vary from brick to brick within the wall. Tensile strength, shear bond strength, and associated fracture energies of the mortar joints and tensile strength and fracture energy of the bricks are the main parameters considered herein. The authors examine how correlation and spatial variability in unit strengths (mortar joints and bricks) affect the variability of ultimate strength and damage progression of clay brick URM walls in one-way horizontal bending. Stochastic analysis in the form of Monte Carlo simulations used a three-dimensional (3D) nonlinear finite-element analysis. The results were validated from a database of available experimental results on masonry four-course beams. It was found that good agreement of peak load exists between the stochastic simulation and the experimental results for the four-course beam subject to horizontal bending.