Researches On Seismic Performance Of Middle And Primary School Masonry Structure Retrofitted With RC Braced Frame

Middle and primary school masonry structure were collapsed or damaged seriously. Therefore, strengthening the existing masonry school buildings, thereby reducing losses of life and property to a minimum in case of an earthquake, has become one of the most important issues on the agenda of the government.In this study, a new strengthening method namely additional RC braced frame is mentioned for a typical middle and primary masonry building with cantilever corridor, which have been built commonly on the rule of the former seismic specifications. Based on the ABAQUS general finite element analysis, some researches have been committed as follows.(1)8 specimens of transverse three-story one-bay masonry structure under low cyclic loading are raised to prove the capability of method, by comparisons of Hysteretic curves of the specimens, Skeleton curves of the specimens, Equivalent viscous damping ratios and Tensile damage variables.(2)6 specimens of longitudinal three-story one-bay masonry building under the low cyclic loading are conducted to further improve that the two materials can cooperate together well and improve its seismic behaviour, by the comparisons of Hysteretic curves of the specimens, Skeleton curves of the specimens, Equivalent viscous damping ratios, Strength degradation and Tensile damage variables.(3)2 specimens of full scale masonry structure are simulated with elastoplastic time-history analysis under Lanzhou and Taft seismic wave respectively to confirm the reinforced effectiveness exact by comparisons of time history of lateral story displacement, base shear force, tensile damage various and et al.Some conclusions are drawn as follows: (1) The non-linear analysis of the masonry structure can be applied to the ABAQUS general finite element software; (2) The additional RC brace frame could work well with the original masonry structure after retrofitted, and improve the whole loading capacity with its advantages of high rigid and bearing capacity; (3) The RC braced frame plays a role in certain constrains of the masonry wall to improve the rigid of the original structure, making the lateral story displacement to be more well distributed along the height of the strucutre; (4) The structure increased the yield-to-strength ratio while shorter the effective yield stage, making a bad effects on the goal of"life-safety under the major earthquake". In the meanwhile, the method does not lower the lightening and ventilation, nor narrower the escape way of corridor. Finally, the reinforced method could conduct the rest middle and primary seismic strengthening work, and also make a certain significant of seismic design of the newly built structures.