北京LG大厦单塔结构整体模型模拟地震振动台试验研究

本文通过对北京LG大厦单塔主体结构1/20整体模型模拟地震振动台试验,测试了模型结构的动力特性、阻尼比及其在8度多遇、8度基本、8度罕遇烈度地震作用下的加速度和位移反应等,研究了模型结构的破坏机理和破坏模式,并根据试验结果和相似理论,推导、分析了原型结构的地震反应。试验及分析结果表明:模型结构第1、2、3阶振型频率依次为:4.319Hz(x向平动)、4.883Hz(y向平动)和6.761Hz(整体扭转),对应阻尼比分别为0.043、0.046和0.026;原型结构对应前3阶振型周期为1.794s、1.587s和1.146s,其扭转、平动周期比为0.64,且在8度多遇和罕遇地震作用下结构最大层间位移角分别为1/1005和1/101,显示原型结构布置基本合理,整体抗震性能较好,能够抵抗所在地区设防烈度下各水准地震作用。论文最后对原型结构的抗震设计提出了一些改进建议。

Shaking table model test of Beijing LG Building

A shaking table test of a 1/20 scale model of the Beijing LG Building is carried out.The model's dynamic properties,damp ratio and responses of acceleration and deformation on the different level earthquakes are studied.Its dynamic behavior,cracking pattern and failure mechanism are discussed as well. Then,according to the model test results,the seismic response of the prototype is deduced and analyzed.Both the test and analytical results show that the frequencies of the first three modes of the model are 4.319(x translation),4.883(y translation) and 6.761Hz(overall rotation) in turn,and the relative damp ratio is 0.043,0.046 and 0.026 respectively.The periods of the first three modes of the prototype are 1.794,1.587 and 1.146 seconds,thus the ratio of the period of the first rotation mode and that of the first translation mode is 0.64.The maximum story drift angle of the prototype under frequent and rare earthquakes is 1/1005 and 1/101 respectively.These all indicate that the prototype has a rational arrangement of structural elements and better anti-seismic behavior.It is able to survive different level earthquakes.Finally,this paper puts forward some suggestions for the design of the structure.