地铁隧道斜交穿越地裂缝的模型试验研究

Research on physical model experiment of metro tunnel obliquely crossing ground fissure

西安地处国内地裂缝发育最强烈的汾渭盆地,地裂缝已成为西安市地铁施工及运营中的一种典型地质灾害。采用比例尺为1∶20的马蹄形衬砌结构模型,研究地铁隧道和地裂缝60°斜交情况下的隧道结构接触压力、隧道结构应变、上部地层变形及隧道下部脱空等情况。研究结果表明:随着地裂缝位错量的增加,隧道结构上部受力表现为上盘压力增加下盘压力减小的趋势;地裂缝活动对上盘地表变形的影响大于对下盘地表变形的影响;沉降初期上盘隧道下部开始出现脱空,下盘隧道靠近地裂缝处土体出现隆起;下盘隧道结构的上部处于受拉下部处于受压状态,上盘隧道结构上部处于先受压后受拉而下部一直处于受拉状态。

Xi5 an is located in Fen nutrient-laden basin which is the most powerful domestic ground fissure development, ground fissure has been a kind of typical geological disasters in Xi5 an metro construction and operation.In this paper, contact pressure of tunnel structure and tunnel structure strain, upper strata deformation and thetunnel lower pavement was studied by the scale of 1 ：20 u-shaped lining structure model when Metro tunnel andthe ground fissures 60 ° oblique,etc. The test results indicate that upper tunnel structure stress shows the upperplate pressure increase and lower plate pressure decreases with the increments of ground fracture dislocation.Ground fissure activities affect on the surface deformation to upper plate is greater than the lower plate. At the beginningof the sedimentation on the tunnel bottom of upper plate began to appear empty, the tunnel of lower plate near the ground fissure soil uplift; The upper tunnel structure of lower plate bear pulling force but the lower partof tunnel structure bear pressure, The upper tunnel structure of upper plate bear pressure before in tension butthe lower part of tunnel structure bear pulling force