带消能伸臂桁架超限框筒结构在长周期地震动作用下的反应分析  

Response analysis of a tall frame-tube structure beyond the code-specification with energy-dissipated outriggers under long-period ground motions

作　　者：韩建平[1,2] 孟岩[1,2] 

机构地区：[1]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050

出　　处：《世界地震工程》2014年第3期15-22,共8页World Earthquake Engineering

基　　金：国家自然科学基金项目(51268036);甘肃省科技支撑计划(1204FKCA126)

摘　　要：由于长周期地震动记录相对缺乏,国内外对长周期地震动作用下高层结构的地震响应研究尚不充分,特别是复杂超限高层结构。从2008年汶川地震记录中选择长周期分量明显的61CAT台站记录作为输入,以一245.60m高超限框筒结构为背景,进行了长周期地震动记录不同设防水准输入下的弹性和弹塑性时程分析,并与相应水准El Centro地震动记录输入下的分析结果进行了对比,对比结果表明长周期地震动记录输入下结构的最大水平位移和层间位移角等指标均显著增大,多遇烈度时算例结构X向、Y向最大层间位移角分别为1/218、1/240,远远超出规范限值。进一步,为了考察消能减震措施对超限高层结构在长周期地震动记录下的减震效果,分别在伸臂桁架水平弦杆、竖向腹杆及及斜撑上布置黏滞阻尼器构成水平型、竖向型及单斜撑型消能伸臂桁架,在长周期地震动记录输入下对带不同阻尼器布置形式的伸臂桁架结构进行了分析,结构的最大水平位移和最大层间位移角等指标明显降低,这一结果表明消能伸臂桁架可以较好地控制结构在长周期地震动记录输入下的地震响应,特别是竖向型阻尼器布置控制效果更好,61CAT记录多遇烈度水准输入下X向和Y向最大层间位移角可减小到1/298和1/312;罕遇烈度水准下X向和Y向最大层间位移角可由原结构的1/58和1/75减小到1/87和1/107。与普通地震动记录输入下的结果相比,长周期地震动输入下消能伸臂桁架发挥的控制作用更加明显。Due to the lack of long - period ground motion records, the influence of long - period ground motion on seismic performance of tall buildings especially for complex buildings beyond the code - specification is not studied sufficiently. In this paper, ground motion records at 61CAT station during 2008 Wenchuan earthquake were chosen as the representative of long period ground motion and a 245.60m high frame - tube structure with outriggers were taken as case study. First, elastic and elastic -plastic dynamic time history analysis under frequently -occurred and rarely -occurred level long period ground motion records were conducted on the structure model. Comparison with analytical results under the corresponding level E1 Centro input shows that the maximum horizontal displace- ment and maximum inter - story drift ratios under long period ground motion records are obviously larger. Maximum inter - story drift ratios along X - direction and Y - direction under frequently - occurred level ground motion records at 61CAT station are 1/218 and 1/240, which are far beyond the coded limitation. Furthermore, in order to investigate the seismic mitigation effects of energy dissipation devices on the long - period tall buildings, viscous dampers were introduced in the different components of outriggers such as horizontal chord, vertical web and sloping web to form the different energy -dissipated outrigger, that is horizontal, vertical and slopingbraced outrigger. The structure models with different energy - dissipated outriggers were further analyzed under long period ground motion inputs. Analytical results show that the maximum horizontal displacement and maximum inter - story drift ratios of the structure with energy - dissipated outriggers are decreased significantly. This indicates that energy - dis- sipation outriggers are efficient to control the seismic responses of the structure under long period ground motion input. Among 3 types of energy - dissipation outriggers, vertical one has the best control effect. For the

关 键 词：超限框筒结构 长周期地震动 消能伸臂桁架 时程分析 

分 类 号：TU352.1[建筑科学—结构工程]