不同缩进比例的大底盘单塔楼结构隔震性能研究

摘要

大底盘单塔楼隔震结构的研究中,尚缺乏缩进比例对隔震性能的影响规律研究.确定了塔楼缩进比例为1∶3的大底盘单塔楼模型,制作安装了基础隔震、层间隔震和抗震这三种结构模型并进行单向振动台试验,通过对比振动台试验和数值模拟结果,验证了数值模拟的准确性,据此建立了塔楼缩进比例分别为1∶1.5、1∶2、1∶2.5和1∶3这四种模型并进行数值分析,结果表明:与抗震结构相比,基础隔震各楼层加速度放大系数随楼层数增加略微增大,顶层放大较为明显,但总体反应接近平动;层间隔震的塔楼加速度反应近乎平动,但底盘的加速度放大系数却比抗震模型大,且随着楼层数的增加而增大;基础隔震各层层间位移减震效果显著,而层间隔震底盘楼层减震效果差,两者底盘响应差异性较大.进一步分析得到,随着缩进比例的增大,三种结构形式的加速度放大系数均有增大的趋势,其中基础隔震与层间隔震模型的增幅较小,而抗震模型的增幅较大.研究结果可为大底盘单塔楼隔震方案的选择和隔震设计提供参考.%In studies on seismic isolation structure for a single tower on a large chassis,few attentions were paid to the influence of the indentation ratio on the seismic isolation effects.A single tower on a large chassis with the tower indentation ratio of 1 ∶ 3 was taken as a model with 3 structural forms including base seismic isolation,interlayer seismic isolation and aseismic one.One-way shaking table test was then conducted on these 3 models.3 models were numerically simulated,their results were verified by comparing them with the results of shaking table tests.Numerical analyses were performed on another four models with the tower indentation ratio of 1 ∶ 1.5,1 ∶ 2,1 ∶ 2.5 and 1 ∶ 3,respectively.The results showed that compared with the aseismic structure model,the acceleration amplification coefficient of each floor of the base seismic isolation model slightly increases with increase in the floor number,but the whole structure response is close to translational motion;for the interlayer seismic isolation model,its acceleration response is close to translational motion,the acceleration amplification coefficient of its chassis is larger than that of the aseismic model,and it increases with increase in the floor number;the damping effect of the interlayer displacement of the base seismic isolation model is remarkable,while the poor damping effect of the interlayer seismic isolation model's chassis is observed;the chassis responses are quite different for the base seismic isolation model and the interlayer seismic isolation one;the acceleration amplification coefficients of the three structural models increase with increase in the indentation ratio,the amplitude increase values of the base seismic isolation model and the interlayer seismic isolation one are relatively small,and that of the aseismic model is larger;the results can provide a reference for seismic isolation scheme selection and seismic isolation design of a single tower on a large chassis.