【摘要】 为研究土-结构动力相互作用系统的地震反应情况,在50g的离心加速度条件下,采用Kobe波作为地震输入,进行两种埋深情况下砂土地基中较大断面地下结构的离心机振动台模型试验。介绍试验设计方案,给出加速度、土压力、位移和应变反应的量测结果。试验结果表明:结构最大弯曲应变发生在柱上端,说明柱是地下结构抗震最不利构件,且柱上端相对于柱下端更为不利;地震作用下结构所承受的总土压力有所增加,并且在地震作用后维持在较高的水平,最大土压力增量与最大总土压力均发生在底板角点处;埋深对地下结构的地震反应有重要影响,本次试验中,结构在对应于原型埋深为5m时的受力情况相比于埋深2.5m的情况更为不利;辅助观测断面与主观测断面相同位置测点的附加弯曲应变峰值较为接近,并且应变反应波形较为一致,表明结构模型地震反应的整体性较好。更多还原

【Abstract】 Two dynamic centrifuge model tests of an underground structure at different depths in sandy soil are performed to investigate the seismic response behavior of the dynamic soil-structure interaction system. The tests are performed at 50 gravitational accelerations and the input motion is Kobe wave. The design of the tests is presented and some of the test results, including acceleration, earth pressure, displacement, and strain responses, are provided. The maximum bending strain of vibration occurs at the column top, indicating that the column is the most unfavorable member of the structure during the earthquake and that the column top is more disadvantageous than the column bottom. The total earth pressure increases under seismic loads and maintains at a high level after the vibration. Both the maximum earth pressure increment and maximum total earth pressure occur at the corner of the bottom plate. The comparison between the test results at two burial depths indicates that the burial depth is an important factor influencing the seismic response of an underground structure. The seismic response of the structure at the prototype burial depth of 5 m is less favorable than that of 2.5 m. The peak values of the additional bending strain responses due to earthquake at some observation positions are close for the major and the auxiliary measuring cross sections, and the shapes of the strain time history curves are similar, which indicates good integrity of the structure model under seismic loads.更多还原