| Prefabricated prestressed reinforced concrete shear wall has many advantages compared with traditional cast-in-place reinforced concrete shear wall,and it also meets the current needs of China’s economic transformation and transformation of the construction industry.In this paper,with the background of a typical shear wall structure project,the seismic performance of the most commonly used shear walls in the cross-sections of one-line and T-shape is studied and the different axial-pressure ratios and prestressed tendons are discussed.The impact of different prestressing degrees on the seismic performance of shear walls under different earthquake resistance levels was studied using the Pushover analysis method of SAP2000,which was combined with load displacement curves,bearing capacity,stiffness,ductility,etc.The main research contents were:(1)The analysis of the shear wall with a cross-section with an axial compression ratio of0.1-0.6 shows that the prestressing increases the stiffness and load-bearing capacity of the shear wall,but decreases the ductility.The increase in load capacity and stiffness is more pronounced at low axial compression ratios.When the axial pressure ratio is between 0.1 and0.3,the reduction of ductility is relatively small,which meets the requirements of seismic resistance.It is recommended that the axial compression ratio of the in-line shear wall should not exceed 0.3 when prestressing is applied.(2)The analysis of the T-section shear wall with an axial compression ratio of 0.1-0.6shows that the application of prestress increases the stiffness and load-carrying capacity of the T-shaped shear wall and reduces the ductility.The increase in load capacity and stiffness is more pronounced at low axial compression ratios.When the axial pressure ratio is between 0.1and 0.4,the reduction of ductility is relatively small,and it meets the seismic requirements.Itis recommended that the axial compression ratio of the T-shaped shear wall should not exceed0.4 when prestressing is applied.(3)The effects of different prestressed tendon layouts for the shear wall of the two cross-sections of the in-line and the T-shape were analyzed at different axial and compressive ratios of 0.3 and 0.4.The reinforcement method is to centrally arrange the edge members,evenly arrange the entire wall,and centrally arrange the wall.The results show that when the prestressed tendons are concentrated on the edge members,their load carrying capacity and stiffness are the largest,and the ductility of the three prestressed tendons has little difference in ductility,and the ductility coefficient of two types of prestressed shear walls in one type and two T types.All of them meet the seismic requirements.It is suggested that the shear wall of the two cross-sections of the I-shaped and T-shaped should be arranged on the edge members in a centralized manner.(4)The prestressed concrete shear walls with different prestressing degrees are analyzed.The results show that as the prestress degree increases,the stiffness and bearing capacity increase,but the increasing speed slowly becomes slower and the ductility increases.The worse it comes.Considering the influence of the prestress degree on the bearing capacity,stiffness and ductility of the prestressed shear wall with I-shaped cross section,it is suggested that the prestress degree should not exceed 0.4 under the first grade earthquake resistance grade,and the prestress degree under the secondary and tertiary earthquake resistance grades.Should not exceed 0.5.(5)Analysis of prestressed concrete shear walls with different prestressed T-section forms shows that as the prestress degree increases,the stiffness and bearing capacity increase,but the increasing speed slowly becomes slower and the ductility increases.The worse.Considering the influence of prestress degree on the bearing capacity,stiffness and ductility of prestressed shear wall with T-section,it is suggested that the prestress degree should not exceed 0.6 under the primary,secondary and tertiary seismic resistance levels. |
