【作者】 张志明； 袁勇；

【Author】 Zhang Zhiming;Yuan Yong;College of Civil Engineering,Guizhou University;Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety,Guizhou University;State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University;

【机构】 贵州大学土木工程学院； 贵州省岩土力学与工程安全重点实验室； 同济大学土木工程防灾国家重点实验室；

【摘要】 为研究谐波激励下软土场地框架式地铁车站的动力响应,开展了1/30比例尺的土-框架式地铁车站振动台模型试验。采用人工模型土、镀锌钢丝和微粒混凝土分别模拟原型软土场地、钢筋和混凝土。通过改变振动台输入地震动频率,探究其对框架式车站及周围场地动力响应的影响规律,分析土-结构系统的加速度及其传递函数、卓越频率、结构动应变、侧墙动土正应力等。试验结果显示:(1)土-框架式车站模型的一阶频率与自由场地的一阶频率一致,印证了地铁车站的地震响应由场地控制;(2)侧墙动土正应力的频谱曲线反映场地加速度响应传递函数曲线的特征,最大动土正应力发生在侧墙最底端;(3)车站结构动应变频谱曲线反映场地加速度响应传递函数曲线的特征,谐波激励下车站站台层柱顶动拉应变最大,建议增强站台层柱顶的抗震性能。更多还原

【Abstract】 To investigate the dynamic responses of frame subway station in soft soil under harmonic excitations,shaking table tests were performed on a 1,/30 scaled soil-frame subway station model.The artificial soil,galvanized steel wire and micro-concrete were used to model the ground,steel rebar and concrete of the prototype,respectively.By changing the frequencies of input motions,influence mechanism of the frequencies on the dynamic responses of both frame subway station and surrounding ground was explored.Experimental data of soil-structure system were analyzed,including the acceleration,transfer function,predominant frequency,structural dynamic strain,and dynamic soil normal stress along the sidewall.The test results revealed that:(1) The first predominant frequency of soil-frame subway station model is consistent with that of free-field model,which proves that the seismic responses of subway station are controlled by the surrounding ground;(2)The spectral characteristics of dynamic soil normal stress reflect the transfer function of the ground acceleration and the maximum stress occurs at the bottom of sidewall;(3) The spectral characteristics of dynamic structural strain reflect the transfer function of the ground acceleration.Under harmonic excitations,the maximum dynamic structural strain occurs on the top of the column belong to the platform floor.It is advised to strengthen the seismic performance of the column top.更多还原