Structural Reliability Analysis of Unreinforced Masonry Walls under Lateral Loads

摘要

Unreinforced masonry shear walls are mainly used to support gravity loads. In the meantime, the walls may need to carry the lateral loads when subjected to winds and earthquakes. The lateral and gravity loads result in tension and shear combined with compression in the masonry wall. The shear or tension failure of the shear wall may lead to the collapse of the building and result in casualties and economic losses. Although the reliability of unreinforced masonry shear walls under compression and/or bending moment has been studied, very little work has been done to investigate the reliability of unreinforced masonry wall under combined gravity and lateral loads. This paper presents a probabilistic model to determine the structural reliability of typical unreinforced masonry walls under combined gravity and lateral loads. A performance limit state is defined for the walls under the combined loads, based on experimental test results and literature review. Shear capacity is established incorporating the uncertainty in compression and shear strength of masonry, ratio of snow/live load to dead load, and ratio of wall height to thickness. Monte Carlo Simulation is used to perform the reliability analysis. Model error is considered in the analysis. Lastly, a sensitivity analysis is performed to identify the key contributors to the reliability of the unreinforced masonry wall under the lateral loads. The results provide a base to evaluate whether consistent safety is achieved for unreinforced masonry walls that are subjected to different load combinations.