地铁车站结构下穿地上建筑物振动台试验研究

Shaking Table Test of Subway Station Structure Passing through Above-Ground Building

为了研究上盖地铁车站结构的地震动力响应规律,开展了相似比1∶40的粉细砂场地振动台试验研究,并对试验过程中加速度、应变和动土压力等指标进行了详细的分析,试验数据表明:(1)随着地震强度的增加,同一监测点的加速度峰值逐渐增大,但加速度的放大系数和变化幅度逐渐减小;(2)土体加速度放大系数最大值位于地表,随着地震强度的增加,加速度放大系数最小值的位置逐渐由模型底部过渡到结构所在位置;(3)模型结构的应变响应随地震强度的增加呈逐渐增大的趋势,应变较大值主要出现在侧墙、中柱与板相交处,尤其是中柱端部位置;(4)地铁车站侧墙跨中的动土压力峰值大于顶部和底部,应适当增大车站中板位置处的侧向刚度或抗变形能力。研究成果可为类似地铁车站结构的抗震设计与分析提供参考依据。

In order to study the seismic dynamic response law of subway station under above-ground building,shaking table test with similarity ratio of 1:40 was carried out in silty sand,and the acceleration,strain and dynamic earth pressure during the test are analyzed in detail.It is shown that:(1)With the increase of earthquake intensity,the peak acceleration at the same monitoring point is gradually increasing,but the amplification coefficient and variation amplitude of acceleration are gradually decreasing;(2)The maximum acceleration amplification coefficient of soil is located on the ground surface.With the increase of earthquake intensity,the position of the minimum acceleration amplification coefficient gradually transits from the bottom of the model to the location of the structure;(3)The strain of the model structure gradually increased with the increase of seismic intensity,and the relatively large strains mainly appeared at the intersection of side walls,middle columns and plates,especially at the end of middle columns;(4)The peak value of dynamic earth pressure in the middle of side wall is greater than the top and bottom,and the lateral stiffness or anti deformation capacity at the middle plate of the station should be appropriately enhanced.The research results can provide a reference for the seismic design and analysis of similar subway station structure.