Experimental study of passive seismic vibration isolation by trench-type periodic barrier
Experimental study of passive seismic vibration isolation by trench-type periodic barrier
复制标题
DOI：
10.1016/j.engstruct.2022.115308
复制
发表时间：
2023-02
影响因子：
5.5
通讯作者：
Nagesh Ramaswamy;Bhagirath Joshi;Jiaji Wang;Xiaoliang Li;F. Menq;Xiaonan Shan;Kalyana Babu Nakshatrala;K. Stokoe;Y. Mo
中科院分区：
文献类型：
--
作者：
Nagesh Ramaswamy;Bhagirath Joshi;Jiaji Wang;Xiaoliang Li;F. Menq;Xiaonan Shan;Kalyana Babu Nakshatrala;K. Stokoe;Y. Mo
隔震系统保护结构并作为与结构的解耦系统，其目的是通过减少传递到结构的振动动能来将结构的运动与入射波解耦。本研究旨在探讨一种利用周期性障壁的非侵入式隔振系统。完成了一个全面的现场试验计划，以评估空槽和周期性障碍物的波浪隔离性能。将预制的一维周期性屏障布置成一长一短的厚屏障，考察屏障长度和单元格数目对屏障隔振性能的影响。本研究中报告的测试程序是P0情况（无周期性基础），与之前的测试情况P1（有周期性屏障和钢筋混凝土基础）和测试情况P2（有周期性屏障和周期性基础的组合）相比，它可以作为参考组。三轴（T-Rex）振动台在三个轴上产生激励，波形包括正弦波、扫频和地震波。每个地震检波器传感器位置记录三轴土壤响应。给出了土的沿着波传播方向的响应、归一化响应和频响函数。各种激励输入具有可比性。研究发现，由于周期性势垒的主导波形，激励方向影响周期性势垒的有效性。通过比较基准工况和测试工况的频响函数，可以确定周期性屏障在衰减区的屏蔽效果。这些衰减区域被认为是周期性势垒的频带间隙。当入射波频率福尔斯落在该频带间隙内时，周期性屏障可以隔离向被保护区域传播的振动。
Seismic isolation systems protect structures and act as decoupling systems with the structure, which aims to uncouple the motion of the structure from incoming waves by reducing the kinetic energy of vibration transferred to structures. This research aims to study a non-invasive vibration isolation system using periodic barriers. A comprehensive field test program is completed to evaluate the wave isolation performance of empty trench and periodic barriers. The precast one-dimensional (1D) periodic barriers are arranged to form one long barrier and one short thick barrier to examine the influence of barrier length and the number of unit cells on the vibration isolation performance. The test program reported in this study is the P0 case (without periodic foundation), which serves as a reference group compared to previous test caseP1 (with periodic barrier and reinforced concrete foundation) and test caseP2 (with a combination of periodic barrier and periodic foundation). The triaxial (T-Rex) shaker truck generates excitation in three axis and the wave form include sine wave, sweep frequency and seismic waves. Each geophone sensor position records the triaxial soil response. The responses of soil along the direction of wave transfer, the normalized responses, and the frequency response function (FRF) are all provided and discussed. Various excitation inputs are comparable. It is found that the excitation directions influence the periodic barrier's effectiveness because of the dominant waveform. When FRF is compared between benchmark case and test cases, the periodic barriers’ screening effectiveness can be determined in the attenuation zones. These attenuation zones are expected to be the frequency band gaps of the periodic barrier. When the incoming wave frequency falls in this frequency band gap, the periodic barrier can isolate the vibration propagating towards the protected region.