Study On HPFL Strengthening Seismic Performance Of Existing RC Shear Wall Structure Under The Different Axial Compression Ratio

Shear wall is the main lateral resistant component in the high-rise buildings,of which its seismic performance of structure during the earthquake is particularly important.There are many factors that can influence the seismic behavior of shear walls,such as the form of cross section,shear span ratio,axial compression ratio and edge reinforcement ratio and its scope,etc.,and the axial compression ratio is an important factor that affects seismic performance of shear wall.A large number of experimental studies and theoretical analyses show that when the axial compression ratio of shear wall is more than 0.6,the displacement ductility ratio will be less than 3.In practical engineering,with the increase of building height,buildings with the axial compression ratio of shear wall that are more than 0.6 become ordinary.In addition,as concrete strength of the shear wall house can not meet the design requirements and the load increase as the building use function changes,all these result in the seismic performance not meeting the requirements of shear wall.As a result,by using HPFL to constraint the concrete shear wall embedded column area,the strength of RC shear wall,plastic deformation capacity,ductility and energy dissipation are increased.At the same time,it can limit the emergence and development of RC shear wall cracks,and bring the reinforced plastic deformation ability to its full play,the HPFL reinforcement has very important practical significance and value to RC shear walls that are under different axial compression ratios.In this paper,two shear walls,under axial compression ratio of 0.2and 0.4,are reinforced by HPFL in the embedded column,then the quasi static low reversed cyclic loading experiment,the finite element numerical simulation,theoretical analysis method have been used.Meanwhile,all these data are compared with the existing data of axial compression ratio of 0.25.Finally,preliminary study has been achieved,and the main research results are as followings:(1)By comparing the results of model test analysis: shear wall that reinforced by HPFL,its cracking load and ultimate bearing capacityis greatly increased,JG1 and JG3 increased by 175% and 119%respectively,and the cracking load JG1,JG2 and ultimate bearing capacity of JG3 level increased by 129%,89.8% and 89.8% respectively.(2)Through the finite element software of axial compression ratio of 0.2,0.25 and 0.4 respectively the three pieces of reinforced and unreinforced model for numerical simulation analysis: HPFL reinforcement layer can obviously limiting shear wall crack development,axial compression ratio,the greater the HPFL after reinforcement of shear wall crack development is slow.(3)Based on the test results,the HPFL embedded column reinforcement theory calculation method of the seismic bearing capacity of shear wall has carried on the preliminary exploration,the results of theoretical calculation are agree well with experimental results,the calculation result has good agreement with the test results are obtained.