摘要
研究目的:为研究盾构隧道差异沉降对道床脱空的影响,本文建立包含管片、钢筋笼、螺栓的错缝拼装三维盾构隧道计算模型,并采用足尺试验对建模方法进行正确性验证.基于此,分析盾构隧道差异沉降作用下,不同道床长度与不同道床伸缩缝位置对道床脱空的影响.研究结论:(1)在相同的隧道差异沉降率下,道床伸缩缝不与隧道环缝重合有利于道床与隧道的共同受力;(2)不同道床长度不影响道床脱空的损伤程度与"纺锤形"的脱空分布形态,但会影响道床底面的脱空范围,道床长度越大,中心块道床损伤范围越大;(3)道床伸缩缝与隧道环缝未重合条件下,道床底部损伤程度加深,沿隧道环缝位置产生贯通道床底面的损伤或脱空,道床伸缩缝越靠近管片中线,道床-隧道整体性越好,道床底部损伤程度越小,损伤范围越大,因此通过优化道床伸缩缝位置、控制道床长度,可以减少盾构隧道差异沉降产生的道床脱空病害;(4)本文研究可为盾构隧道内道床脱空病害整治提供参考.
Abstract
Research purposes:To assess the effects of differential settlement on disengagement in shield tunnel invert-filling,a numerical model of a staggered 3D shield tunnel was developed,integrating segments,rebars,and bolts.The model's accuracy was validated through a full-scale test.This research examines the influence of varying invert-filling lengths and different expansion joint placements on invert-filling disengagement due to differential settlement.Research conclusions:(1)With consistent rates of tunnel differential settlement,non-overlapping expansion joints in the invert-filling with the tunnel ring joints contribute positively to the combined strength of the invert-filling and the tunnel.(2)Variations in invert-filling lengths do not alter the extent of damage or the'spindle'pattern of disengagement;however,they do impact the disengagement scope on the invert-filling's bottom surface.An increase in invert-filling length correlates with a broader damage range in the central block invert-filling.(3)When the invert-filling's expansion joint does not coincide with the tunnel ring joint,the damage severity at the invert-filling's base intensifies,with damage or disengagement occurring along the tunnel ring joint.The proximity of the invert-filling's expansion joint to the segment's midline enhances the invert-filling-tunnel integrity,reduces the damage severity at the base,and increases the damage range.(4)The research in this paper can provide reference for the disease treatment of invert-filling disengagement in shield tunnel.
维普
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