Large-scale shaking table test on tall buildings with viscous dampers considering pile-soil-structure interaction
Large-scale shaking table test on tall buildings with viscous dampers considering pile-soil-structure interaction
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DOI：
10.1016/j.engstruct.2020.110960
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发表时间：
2020-10
影响因子：
5.5
通讯作者：
Jinping Yang;Zheng Lu;Peizhen Li
中科院分区：
文献类型：
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作者：
Jinping Yang;Zheng Lu;Peizhen Li
为了更好地了解桩-土-结构相互作用(PSSI)对桩、土、结构动力响应和粘滞阻尼器性能的影响，进行了群桩基础软土上设置非线性粘滞阻尼器高层建筑的一系列大型振动台试验。研究了两种不同的模型，一种是在考虑土-结构相互作用的情况下设置粘滞阻尼器的固基结构，另一种是在软土中设置粘滞阻尼器的3×3群桩基础的剪切层状土容器结构。上部结构是一个12层的钢筋混凝土(RC)框架。选择了上海基岩波、1995年神户地震和1999年集集地震的地震激励进行了振动台试验。最后，建立了带粘滞阻尼器的土-桩-结构的三维数值模型，并对其进行了验证。试验结果表明，PSSI体系具有较长的自振周期，试验后结构的自振频率下降较小。此外，PSSI对频率的影响远大于阻尼比。此外，与固定基础条件相比，PSSI对结构的弹塑性层间位移的减小比对加速度和剪力的影响要大得多。然而，由于存在明显且较大的摇摆和平移构件，结构的整体变形可能会增加。更有趣的是，与固定基础模型相比，PSSI效应降低了粘滞阻尼器的滞回性能和减震结构动力反应的效率。因此，忽略SSI效应可能会导致上部结构地震反应的结果不切实际，夸大了非线性粘滞阻尼器的性能。在粘滞阻尼器和结构的设计中，考虑地震SSI效应具有重要意义。
A series of large-scale shaking table tests of tall buildings with nonlinear viscous dampers on soft soils in pile group foundations are performed to better understand the effect of the seismic pile-soil-structure interaction (PSSI) on the dynamic responses of the pile, soil, structure and the performance of the viscous dampers. Two different models are investigated, including a fixed-base structure with viscous dampers, representing the situation ignoring the soil-structure interaction (SSI) and a structure with viscous dampers supported by 3-by-3 pile group foundation in soft soil within a shear laminar soil container. The superstructure is a 12-story reinforced concrete (RC) frame. The seismic excitations of Shanghai Bedrock waves, 1995 Kobe earthquake and 1999 Chi-Chi earthquake events are selected and used in the shaking table tests. Finally, a three-dimensional numerical model is developed and verified to be appropriate for capturing the dynamic responses of soil-pile-structure with viscous dampers. Based on the experimental results, the PSSI system has longer natural periods and the frequencies decrease more lightly than the fixed-base structure after the tests. In addition, the influences of PSSI on the frequencies are much greater than the damping ratio. Moreover, by comparing with the fixed-base conditions, PSSI tends to decrease elastic-plastic inter-story drift of the structure more greatly than the acceleration and shear force. However, the overall deformation of the structure may increase due to the obvious and large rocking and translational components. More interestingly, the hysteretic performance and the efficiency of viscous dampers on mitigating the structural dynamic responses are reduced by the PSSI effect compared with the fixed-base models. Consequently, ignoring the SSI effects may result in unrealistic results of the seismic responses of the superstructure and overstate the performance of the nonlinear viscous dampers. It is of great importance to consider the seismic SSI effect in the design of viscous dampers and structures.