In-plane Seismic Behavior of Brick Masonry Walls Strengthened by Externally Added Thin Reinforced Concrete Columns with Irregular Cross-Sections

Abstract:

To minimum the impact on the facade of existing buildings avoid excessive occupation of structural space， a reinforcement method using the thin reinforced concrete （RC） columns with irregular cross-sections was proposed to enhance the integrity of existing masonry structures， focusing on the in-plane seismic behavior of masonry walls strengthened with externally added thin RC columns with irregular cross-sections. Four 1/2-scale clay brick masonry wall specimens with the same RC columns and different lengths were designed and fabricated. Pseudo-static cyclic loading tests were conducted to investigate the in-plane confining effect of the thin RC columns on the masonry walls. Subsequently， the discrete element method （DEM） was employed to numerically simulate the tested specimens and prototype walls. Existing DEM algorithms were modified， and based on the validated simulation methods， key parameters affecting the in-plane strengthening effectiveness of brick walls were analyzed. Both experimental and numerical results demonstrate that the proposed thin RC columns with irregular cross-sections could effectively improve the in-plane mechanical performance of brick walls. The strengthening walls exhibit significantly enhanced in-plane shear bearing and deformation capacities. From the perspective of enhancing the in-plane shear capacity of the wall， for a 240 mm thick brick wall， the effective confine length of two adjacent columns within the wall plane is no more than 7 200 mm.