摘要
西安火车站改扩建东配楼项目由三个平面不规则的单体建筑通过大跨度桁架进行连接,结构质量与刚度分布差异较大,且平动与扭转振动反应的耦联效应显著。为研究不规则连体结构的抗震性能,选取子结构进行了1∶10缩尺模型振动台试验,分析设防、罕遇及超罕遇地震作用下结构的破坏模式、动力特性以及加速度、位移、内力响应,评价连体结构的抗震性能。结果表明:在8度设防地震作用下,结构的自振频率呈线性退化,单体频率下降约20%。在8度罕遇地震作用下,框架梁端形成塑性铰,小三角区角柱首先进入塑性工作状态,各区频率降低超过了57%,实测层间位移满足现行GB 50010—2010《建筑抗震设计规范》要求。在9度超罕遇地震作用下,叠层桁架由于位移过大导致扭转效应显著,连接支座处发生破坏,但结构并未发生整体倒塌。连体结构的薄弱部位于第2层,小三角区侧向刚度较弱,建议在该区增设支撑或剪力墙。采用柔性连接能有效降低大跨桁架的地震作用,但面外扭转效应显著,受竖向地震作用影响较大。
The renovation of Xi’an railway station East annex building consists of three irregularly-shaped buildings connected by long-span trusses. The structural weight and stiffness distribution are notably irregular, and the flat twisted coupling effect is significant. To study the seismic performance of the structure, shake table test of 1/10 scale model was performed. The failure mode, dynamic characteristics, acceleration, displacement, and internal force response of the structure under fortification, rare and super rare intensity conditions were analyzed, and the overall seismic performance of the structure was evaluated. The results show that under the 8-degree design earthquake, the natural frequency of the structure degrades linearly and decreases by about 20%. Under the rare earthquake of 8 degrees, plastic hinges are formed at the ends of the frame beams. The corner columns in the small triangular area first yield, and the frequency degradation exceeds 57%. The measured inter-story displacement meets the requirements of the current Code for seismic design of buildings GB 50011-2010. Under the action of a rare earthquake at 9 degrees, the laminated truss has a significant torsion effect due to excessive displacement, and the connecting supports are damaged, but the structure collapse is not observed. The weak part of the structure is on the second floor, and the lateral stiffness of the small triangle area is weak. It is recommended to add a support or shear wall in this area. The flexible connection can effectively reduce the seismic action of long-span trusses, but the out-of-plane torsional effect is significant, and the vertical earthquake action has a notable effect.
作者
郭宏超
张博明
李晓蕾
蔡玉军
李慧
高志宏
GUO Hongchao;ZHANG Boming;LI Xiaolei;CAI Yujun;LI Hui;GAO Zhihong(School of Civil Engineering and Architecture,Xi'an University of Technology,Xi'an 710048,China;Shaanxi Key Laboratory of Loess Mechanics and Engineering,Xi'an University of Technology,Xi'an 710048,China;China Railway the First Survey and Design Institute Group Co.Ltd,Xi'an 710043,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2022年第6期155-164,共10页
Journal of Building Structures
基金
国家自然科学基金项目(51978571)
陕西省杰出青年科学基金项目(2021JC-41)
陕西省教育厅重点实验室科研项目(18JS072)
铁一院科学研究计划项目(院科16-59-01)。
关键词
不规则连体结构
地裂缝
大跨度桁架
柔性连接
振动台试验
动力特性
irregular connected structure
ground fissure
long-span truss
flexible connection
shaking table test
dynamic characteristics
