The Seismic Strengthening Technology Research Of Residential Brick Wall

A lot of earthquakes happen in China, and the seismic zone is very extensive. What's more, most of the earthquake hazards which happened in the rural areas and small town caused great damage of residential houses. Due to its low cost and easily to get the materials, masonry structure is always a major structure forms in towns and the framers'buildings in China. But in the previous devastating earthquake, especially in the earthquake on May 12, 2008 Wenchuan, most of the brick walls aroused inclined cracks or cross-diagonal cracks because the shear strength was not enough. These leaded to the destruction of masonry structure, which caused large numbers of casualties and heavy property losses. Therefore, it is very necessary to do some research work to improve the seismic resistant capacity of residential brick walls.This paper tries to develop a new composite mortar which has low price and can meet the requirements of reinforcement. The effects of the white latex glue and construction glue on the mechanical properties of composite mortar were tested and observed, and the effects of the elements of white latex glue and gray sand ratio on the flexural strength, compressive strength, the ratio of flexural strength to compressive strength, and adhesive tensile strength were investigated in detail in this paper. And then a new reinforced composite mortar that is suitable for residential brick walls was fabricated. The mix proportion of the composite mortar is gray sand ratio of 1:3, dosage of 6% white latex glue, dosage of 0.5% super plasticizer and dosage of 0.1% cellulose ether.In this paper, the ABAQUS software simulated the non-linear mechanical properties of residential brick walls with concrete damaged plasticity model. This modeling analysis method can reflect the damage process of the brick wall under cyclic loading and can get accurate ultimate load of the wall, by comparing the finite element calculation result with the test data of existing literature. This shows that using ABAQUS software and its material model to analysis residential brick walls is reliable. And then the seismic performance of using ferrocement laminate to reinforce brick walls was studied by using ABAQUS software. The results indicated that the reinforcement method can effectively improve the ultimate bearing capacity of the residential brick wall, enhance its integrity, ductility and the energy dissipation capacity, and improve the seismic resistant capacity. The parameters of the reinforcement method were analyzed. The results indicated that the economic and reasonable parameters are 6mm in diameter for reinforcing steel bar, 300mm×300 mm for steel mesh size, M30 for composite mortar strength grade and 25mm for reinforcement layer thickness. Considering the economic and technical conditions of rural regions, using ferrocement laminate to reinforce residential brick wall which is an effective seismic strengthening technology, is worth to promote.This paper is part of the research about the defensive project, which is against seismic disasters in Gansu province after Wenchuan earthquake.