Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure patte...Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure pattern and damage occurs mainly in the RC section with weak shear capacity in the transfer columns. There is a large difference in the bearing capacity and ductility of the transfer columns according to the test results, which indicates that the strengthening effect of diverse structural measures is quite different. The section ratio of I-section-encased steel and the axial compression ratio also have a great influence on the bearing capacity and ductility. Although the bearing capacity of transfer columns with additional longitudinal bars and additional X bars is relatively large, they have poor deformation capacity. Setting more stirrups along the columns is the best structural measure to enhance the seismic performance. The studs on the I-sectionencased steel by welding can help to complete the stress transfer between the steel and concrete, and avoid performance degradation of the two materials due to bonding failure.展开更多
Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling...Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling friction is proposed.SRF is capable of realizing a parallel arrangement of sliding friction and rolling friction,and the coefficient of dynamic friction shows variability.The proposed static tests on composite bearings were conducted to investigate the effects of the number of shims,loading speed and vertical pressure on the dynamic friction factor.Test results show that the coefficient of dynamic friction first generally decreases and then increases with an increase in sliding speed,prior to again decreasing with an increase in vertical pressure.The dynamic friction factor increases and then decreases with an increase in the number of shims for a four-roll ball.It decreases and then increases with an increase in the number of shims for a five-roll ball.Based on finite element analysis,modeling and analyzing the effects of the coefficient of friction,the number of balls and the number of shims on the hysteresis performance of the support and derive its skeleton curve.The SRF hysteretic performance,dynamic friction factor and the number of rolling balls and shims show significant correlation.展开更多
基金Supported by:National Natural Science Foundation of China under Grant No.51208175the Fundamental Research Funds for the Central Universities under Grant Nos.2015B17514 and 2016B20514
文摘Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure pattern and damage occurs mainly in the RC section with weak shear capacity in the transfer columns. There is a large difference in the bearing capacity and ductility of the transfer columns according to the test results, which indicates that the strengthening effect of diverse structural measures is quite different. The section ratio of I-section-encased steel and the axial compression ratio also have a great influence on the bearing capacity and ductility. Although the bearing capacity of transfer columns with additional longitudinal bars and additional X bars is relatively large, they have poor deformation capacity. Setting more stirrups along the columns is the best structural measure to enhance the seismic performance. The studs on the I-sectionencased steel by welding can help to complete the stress transfer between the steel and concrete, and avoid performance degradation of the two materials due to bonding failure.
文摘Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling friction is proposed.SRF is capable of realizing a parallel arrangement of sliding friction and rolling friction,and the coefficient of dynamic friction shows variability.The proposed static tests on composite bearings were conducted to investigate the effects of the number of shims,loading speed and vertical pressure on the dynamic friction factor.Test results show that the coefficient of dynamic friction first generally decreases and then increases with an increase in sliding speed,prior to again decreasing with an increase in vertical pressure.The dynamic friction factor increases and then decreases with an increase in the number of shims for a four-roll ball.It decreases and then increases with an increase in the number of shims for a five-roll ball.Based on finite element analysis,modeling and analyzing the effects of the coefficient of friction,the number of balls and the number of shims on the hysteresis performance of the support and derive its skeleton curve.The SRF hysteretic performance,dynamic friction factor and the number of rolling balls and shims show significant correlation.
