锥形非固结隔震结构理论与振动台试验研究

Theoretical and experimental study on unconsolidated isolation structure

为了分析锥形非固结隔震结构的减震效果、支座耗能机理及支座受拉性能,对一缩尺1∶4的锥形非固结隔震钢框架结构模型进行了水平和竖向单向地震波输入下的振动台试验研究。分析了不同类型及强度的地震波作用下的结构上部及隔震层地震反应。试验结果表明,结构模型在8度和9度罕遇地震作用下,与其台面输入加速度峰值相比,其隔震层的加速度峰值减小10%～20%,上部结构顶层加速度峰值增加10%～50%,但和普通抗震结构相比具有明显的减震效果。在不同单向地震作用下,锥形非固结支座的滞回曲线饱满匀称;其上下盖板会在地震作用下产生错动位移,同时挤压粘弹性体消耗地震能量,耗能机理明确;地震波特性对支座受拉性能影响明显,但没有出现倾覆倒塌现象。锥形非固结隔震支座具有良好的减震性能,对低层建筑结构的减震具有明显的推广价值。

To analyze vibration reduction effect of isolation structure with unconsolidated conical bearings, energy dissipation mechanism of bearings and tension performance of bearings, the shaking table tests of a 1：4-scale model of two-floor steel frame with unconsolidated conical bearings under the input of horizontal or vertical earthquake were conducted. Seismic re- sponses of top structure and conical bearing were analyzed by inputting earthquake wave with different magnitudes and types. Experimental results indicated that compared with table input peak acceleration, the max acceleration of isolation layers of the structure had been reduced by 10%-20%, and the max acceleration of model top structure had an increment of 10%-40% under unusual ground motions of 8 and 9 intensity. In spite of this, it had obviously vibration reduction effect compared with normal anti-seismic structure. The hysteretic curves of the bearing under different earthquake waves were full and symmetric . The upper and lower covers dissipated earthquake energy by compressing the viscoelastic material when they formed relative displacement. The energy dissipation mechanism of bearings was clear. The effects of ground motion characteristics on tension performance of bearings were obvious, but overturning and collapse of model structure didn＇t appear. The results of the test indicate that the unconsolidated conical bearing has good damping effect and the promoted value to lower-layer building for vibration reduction.