明-暗挖地铁车站框架结构接头刚度对抗震性能的影响研究

Influence of Open-buried Excavation Metro Station Joint Stiffness on Seismic Per-formance

上海轨道交通14号线静安寺站位于城市核心区,受限于周边运营设施与建筑保护需求,采用顶管结构衔接两侧明挖法框架结构式车站。该复合工法建设的车站结构存在刚度差异大,衔接方式对地震效应的影响未知等技术难题。为此开展了几何比尺1/20的结构振动台试验,研究该车站的抗震性能。试验结果表明:车站顶管与框架结构之间采用柔性连接时,地震波沿车站横向输入时顶管加速度峰值比纵向输入时大,框架结构质量较大的一端顶管加速度峰值较大;采用刚性连接时环缝张开量整体大于采用柔性连接的工况。已有理论分析较适用于柔性连接工况,当最大环缝张开量较小时,试验值相对理论值偏小。

Jing′an Temple Station of Shanghai Metro Line 14 is located in urban core area.Due to the restriction of surrounding operating facilities and the demand for building protection,the station adopts a combined structure in which the pipe-jacking structures are connected to the cut-and-cover frame structures on both sides.However,the station structure constructed by the combined excavation method has technical problems such as large differences in stiffness and unknown seismic effects.Therefore,a shaking table test with a geometric scale of 1/20 is carried out to investigate the seismic performance of the station structure.Using the flexible connection,the peak accelerations of pipe-jacking structures when the seismic wave is input along the transverse direction of the station are larger than those along the longitudinal direction.The peak accelerations of pipe-jacking at the end with the larger mass is larger.Using rigid connection,the overall circumferential-joint extensions is larger than that of the flexible connection.The theoretical analysis is more suitable for flexible connection conditions.When the maximum circumferential-joint extension is small,the experimental value is smaller than the theoretical value.