运营地铁盾构隧道结构振动响应实测分析

摘要

Shield tunnels of Shanghai Metro Line No. 8 are taken as monitoing objects for scientific research in operation. Out of the shield tunnels the single-round shield tunnel with and without steel spring floating slabs and the DOT (double-O-tube) shield tunnel with straight or stagger joints are selected, and vertical vibration responses of both track beds and standard blocks are compared. The results show as follows:Under the conditions of laying monolithic track beds and excluding superimposed vibration caused by meeting of trains in up and down directions,the vertical peak vibration accelerationy at the same measuring points in the DOT shield tunnel is smaller than that in the single-round shiled tunnel,and the vibration response time of the standard block in the DOT shield tunnel is smaller than that in the single-round shield tunnel; when a single train is through the monitoring section in the DOT shield tunnel, Superimposed vibration in meeting of up and down trains intensifies the vibration strength and prdong the vibration response time of the DOT structure;in the single-round shield tunnel, compared to the other two forms of shield tunnels, structural vibration responses are significantly decreased by the isolation effect of steel spring floating slabs; for the track beds and standard blocks in the three forms of shield tunnels, the spectrum range of the vertical vibration acceletration is between 0 Hz and 150 Hz and that of the peak acceleration is the same,lying between 35 Hz and 70 Hz,the vibration acceleration level of track beds is from 95 dB to 123 dB and that of standard blocks is from 82 dB to 94 dB,thepeak vibration acceleration of track beds being larger than that of standard blocks.%以上海轨道交通八号线运营地铁盾构隧道为科研监测对象,选取目前上海广泛采用的3种典型通、错缝拼装盾构隧道,有、无铺设钢弹簧浮置板的单圆盾构隧道和双圆盾构隧道,分别对隧道内道床和标准块的振动响应进行对比分析.结果表明,采用整体道床,不考虑上、下行列车交汇叠加振动影响的情况下,相同测点处竖向振动峰值加速度,双圆盾构隧道小于单圆盾构隧道,双圆盾构隧道内标准块的振动响应时间小于单圆盾构隧道;双圆盾构隧道内上、下行列车交汇时叠加振动将加大结构的振动强度,同时延长结构的振动响应时间;单圆盾构隧道内,钢弹簧浮置板道床具有显著的隔振效果,相比其他两种形式盾构隧道,可大幅减小结构的振动响应;3个区间隧道内,道床和标准块的竖向振动加速度频谱介于0～150 Hz,峰值加速度所处频段基本相同,介于35～70 Hz,加速度振级分别介于95～123 dB和82～94 dB,道床的竖向振动峰值加速度大于标准块的竖向振动峰值加速度.