To investigate the seismic performance of underground structures under the action of the structure-soil interface, in this study, experiments were performed using plexiglass structures (two pieces) and a concrete structure (one piece) as the research objects. The surface of one plexiglass structure was prepainted with a layer of cement mortar as the contact surface between the structure and soil, and the other plexiglass structure was not treated and used for comparison. A rigid model box measuring 2.25 m × 2.25 m × 1.5 m was placed on a 3 m × 3 m shaking table, and the box was filled with the configured model soil and the underground structure prepared in advance. Input transverse uniform excitation was imparted to the whole system. A shaking table model test was performed on the underground structures to analyse the acceleration response, stress strain, and earth pressure changes in the underground structure, and the influence of the contact surface on the seismic dynamics of the underground structure was evaluated. The test results showed that under uniform excitation, the dynamic characteristics of the underground structures were greatly affected by the intensity and depth of the seismic waves. (1) When the soil-structure contact was considered, the stress and strain of the structures increased significantly, and the stress-strain value was significantly greater than the stress-strain value of the soil-structure interface in a fully bonded state. (2) There were inconsistencies between the acceleration peak curve of the plexiglass structure considering the contact effect and the acceleration peak curve of the plexiglass structure without considering the contact effect. The difference between the two lies mainly in the corresponding maximum peak acceleration and the Fourier spectrum amplitude. With respect to the value and frequency composition, regardless of whether the input acceleration intensity was 0.2 g or 0.5 g, the peak acceleration of the organic structure was greater when the contact surface effect was considered than without the contact surface effect. Therefore, the structure-soil interface needs to be considered in actual engineering. The presence of the contact surface improves the safety of the structure and is helpful for seismic design. The results of this study provide a basis for further research on the influence of soil-pipe contact on the seismic response of underground structures.

中文翻译：

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考虑结构-土界面影响的地下结构振动台试验分析

为研究结构-土界面作用下地下结构的抗震性能，本研究以有机玻璃结构（两件）和混凝土结构（一件）为研究对象进行了试验。一个有机玻璃结构表面预涂一层水泥砂浆作为结构与土壤的接触面，另一个有机玻璃结构未经处理用于对比。将一个2.25 m×2.25 m×1.5 m的刚性模型箱放置在3 m×3 m的振动台上，箱内填满配置好的模型土和预先准备好的地下结构。输入横向均匀激发被赋予整个系统。对地下结构进行振动台模型试验以分析加速度响应，地下结构的应力应变和土压力变化，以及接触面对地下结构地震动力学的影响进行了评估。试验结果表明，在均匀激励下，地下结构的动力特性受地震波强度和深度的影响较大。(1) 考虑土-结构接触时，结构的应力应变显着增加，应力-应变值明显大于完全结合状态下的土-结构界面的应力-应变值。(2)考虑接触效应的有机玻璃结构加速度峰值曲线与不考虑接触效应的有机玻璃结构加速度峰值曲线存在不一致。两者的区别主要在于对应的最大峰值加速度和傅立叶谱幅值。就数值和频率组成而言，无论输入加速度强度是0.2 g还是0.5 g，考虑接触面效应时有机结构的峰值加速度都比不考虑接触面效应时更大。因此，在实际工程中需要考虑结构-土界面。接触面的存在提高了结构的安全性，有利于抗震设计。研究结果为进一步研究土管接触对地下结构地震响应的影响提供了依据。