摘要
为了完善部分充填圆形钢管混凝土桥墩的抗震设计理论及其工程应用,对2座采用此类桥墩的两跨高架桥缩尺模型(相似比为1∶6.7)进行了强地震动输入下的破坏性振动台试验,研究无偏心部分充填圆形钢管混凝土桥墩和有偏心部分充填圆形钢管混凝土桥墩的破坏机理和地震响应。研究发现无偏心桥墩在墩底附近产生了均匀的钢管局部屈曲变形和明显的水平裂缝,而有偏心桥墩并没有产生水平裂缝,所以无偏心桥墩的纵桥向墩顶位移远大于有偏心桥墩。同时,受横桥向恒载偏心的影响,有偏心桥墩的墩顶横桥向位移和墩底局部屈曲变形主要集中在靠近中轴线的一侧,塑性发展区域也大于无偏心桥墩,这使得其墩顶横桥向最大位移大于无偏心桥墩。不过,由于有偏心桥墩并未发生开裂,所以其横桥向残余位移与无偏心桥墩相差不大,均在3 cm左右,验证了有偏心部分充填圆形钢管混凝土桥墩若经过合理的截面设计,其抗震性能也能满足既定的要求。此外,恒载偏心使得有偏心桥墩在横桥向两侧所耗散的能量不相等,可能会导致其横桥向两侧的累积塑性变形存在差异,不利于其优越的抗震性能和耗能能力的充分发挥。因此在设计有偏心部分充填圆形钢管混凝土桥墩时,需要合理选取混凝土充填高度和径厚比等结构参数,减少恒载偏心对其抗震性能的不利影响。
In order to develop the seismic design theory and engineering application of partially concrete-filled circular steel tubular piers,destructive shaking table tests on two 1∶6.7 scale two-span viaducts with such piers were carried out under strong ground motion inputs.Then,the seismic response and the failure mechanism of the non-eccentric and eccentric partially concrete-filled circular steel tubular piers were studied.The tests show uniform local buckling of the steel tube and a clear horizontal crack near the bottom of the non-eccentric pier,whereas the eccentric pier had no cracks;thus,the longitudinal displacement at the top of the non-eccentric pier is larger than that of the eccentric pier.Owing to the transverse eccentricity of the dead load,the transverse displacement at the top and the local buckling near the bottom of the eccentric pier are concentrated on the side close to the central axis,and the length of the plastic zone is larger than that of the non-eccentric pier,causing a larger maximum transverse displacement at the top of the eccentric pier.However,the transverse residual displacement of the eccentric pier is approximately 3 cm,which is comparable to the non-eccentric pier because it has no cracks.This confirms that the eccentric partially concrete-filled circular steel tubular piers can achieve the same level of seismic performance provided they are well-designed.Meantime,owing to the transverse eccentricity of the dead load,the energy dissipation on each side of the eccentric pier in the transverse direction is not the same.This could lead to differences in cumulative plastic deformation,and the superior seismic performance and energy dissipation ability cannot be fully exploited.Therefore,it is necessary to rationally select the structural parameters,such as concrete filling height,radius-thickness ratio,etc.,to reduce the negative effects of the eccentricity of the dead load.
作者
徐艳
王臻
后藤·芳显
海老泽·健正
XU Yan;WANG Zhen;YOSHIAKI Goto;EBISAWA Takemasa(State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Department of Civil Engineering,Nagoya Institute of Technology,Nagoya 466-8555,Japan)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2019年第12期177-185,共9页
China Journal of Highway and Transport
基金
教育部地震工程国际合作联合实验室(ILEE)项目
国家重点研发计划重点专项项目(2017YFC1500702)
国家自然科学基金项目(51878492).
关键词
桥梁工程
部分充填钢管混凝土桥墩
振动台试验
抗震性能
破坏机理
地震响应
bridge engineering
partially concrete-filled steel tubular pier
shaking table test
seismic performance
failure mechanism
seismic response
