Study On Influence Of Opening Size On Seismic Performance Of Shear Wall Before And After Strengthened

Shear wall structure has the advantages of high lateral stiffness and good seismic performance,because of which the shear wall is widely used in modern high-rise buildings.However,in practical engineering,openings are often setted in shear wall structures due to the changes of building functions,housing transformation,and so on,which greatly changes the seismic performance of shear wall structure.Besides,the earthquake damage shows that the size of the opening has a significant impact on the seismic performance of the shear wall.Based on this,the seismic performance of the post-construction shear wall with the opening size of550 mm × 650mm(12%),700 mm × 850mm(20%)and 850 mm × 1000mm(28%)before and after strengthened by steel is studied by the method of combining experimental research and numerical simulation.The main research results are as follows:(1)The pseudo static tests of one shear wall specimen without opening and three specimens with opening size of 550 mm × 650mm(12%),700 mm × 850mm(20%)and 850mm× 1000mm(28%)are carried out.The results show that the bearing capacity of the shear wall with post-construction opening is lower than that of the unopened shear wall,and decreases with the increase of the opening size.The initial stiffness ductility of the shear wall with the post-construction opening size are decreasing first and then increasing with the increase of the opening,and there is a significant mutation between 20% and 28% of the opening rate.The opening significantly reduces the energy consumption capacity of the shear wall specimens,which is 80.7%,73.0% and 63.3% lower than that of the shear wall without opening.(2)The pseudo static tests were carried out on the steel-bonded specimens of the postconstruction opened shear wall with the opening size of 550 mm × 650mm(12%),700 mm ×850mm(20%)and 850 mm × 1000mm(28%).The results show that the bearing capacity of the shear wall strengthened with the bonded steel is lower than that of the shear wall without opening,but the bearing capacity of the shear wall with the opening size of 550 mm × 650 mm is mostly restored to that before opened;The ductility of the specimens strengthened by bonded steel increases first and then decreases with the increase of the opening size.Only the ductility of the specimens with the opening size of 700 mm × 850 mm is better than that of the shear wall without opening.The energy consumption capacity of the specimens is lower than that of the shear wall without opening,and the larger the size of the opening,the worse the energy consumption capacity.(3)The seismic performance of the shear wall with the opening size of 550 mm × 650mm(12%),700 mm × 850mm(20%)and 850 mm × 1000mm(28%)before and after the steelbonded strengthening is analyzed.And the reinforcing effect of steel-banded method to strengthen the shear wall with post-construction opening is studied.The results show that the strengthening method of steel-bonded can restrain the crack development of the corner of the opening and improve the integrity of the shear wall.After strengthened,the bearing capacity of the shear wall is significantly improved,and the lifting rate increases with the increase of the opening size;And the ductility and energy consumption capacity of the post-construction opened shear wall with the size of 550 mm × 650 mm and 700 mm × 850 mm are obviously improved after strengthened.However,the ductility and energy consumption capacity of the specimens with the opening size of 850 mm × 1000 mm are lower than those without strengthening due to the peeling failure between steel plate and concrete.(4)The sudden change of seismic performance of the shear wall with the opening rate of20%,22%,24%,26% and 28% was analyzed by using the finite element software ABAQUS.The simulation results show that before the steel-bonded strengthening,the failure mode of the specimen changes from the shear failure of the wall limb into the "limb hinge" failure with the mutation point of 24% opening rate,while the ductility does not change obviously;After the steel-bonded strengthened,the failure form and the compression damage of the specimen are all the wall limb compression failure.But with the increase of the opening rate,the ductility of the specimen reduces first and then enhances with the mutation point of 24% opening rate.There are 77 figures,23 tables and 97 references in this dissertation.