Study On Grouting Reinforce Technique Of The Seismic Damage Masonry Building And Comprehensive Evaluation

Multistory masonry building is one of structures mostly used in civil building of our country. Because of getting material and construction easily, the costs of the buildings are also low, the application of this kind is widely and with large develop value in a long period. However, the basic structural member of the masonry building is the only element to bear dead weight and seismic actions, the tensile strength and shear force is low. Besides, this kind of structure is brittleness and with bad ductility, which made them destroyed badly during the earthquake.Badly destruction appeared in masonry building during"5.12"earthquake. Take the SWUST for instance; over 80% of damages are masonry building. Different enforcements were set to different component, different forms and different degrees of destructions. Gravitational grouting method, pressure grouting method, mesh reinforcement with cement mortar methods, and mesh reinforcement with concrete walls are the common way to enforce the bearing walls. It is feasible and economical to use different methods to different destructions.After investigation, it is found that most of the seismic damage of masonry walls is the shear crack, and one single method is not capable to attain the demands, which need to combine with two or three kinds of methods to do the compound enforcement. Two kinds of the compound enforcements were proposed in the article, the one is compound with pressure grouting and mesh reinforcement with cement mortar methods, another one is compound with pressure grouting and mesh reinforcement with concrete walls. The two ways are used for the masonry walls with different degrees of damages. Improvements in the traditional formula of enforcements from CABR were set focus on the shearing forces in the compound walls after enforcement. Shearing force improvement coefficientγand reduction coefficient of the shearing force for the Ladder-shaped cross-sectionαwere introduced in the article. New fixing method proposed using the compound enforcement, with new grouting material, new kinds of equipment, new ways of construction and a theory of reliability evaluation. Finally, comprehensive benefit analysis were set and used to the actually works in disaster area.