软弱围岩隧道掌子面及超前核心土挤出位移特征研究

发布时间：2018-03-18 14:53

本文选题：隧道　切入点：软弱围岩　出处：《岩土力学》2017年S1期 　论文类型：期刊论文

【摘要】：为研究软弱围岩隧道掌子面及超前核心土的挤出位移特征,用Solexperts AG公司生产的GMD滑动测微计对湄渝高速岐山隧道F215构造破碎带区域进行了挤出位移实测,通过有限差分程序进行系列数值试验,着重研究了隧道穿越软弱围岩期间挤出位移的变化特征,并分析了破碎带长度和硬软岩刚度比的影响。结果表明,(1)挤出位移的大小可反映前方围岩质量,挤出位移在超前核心土内的分布可反映前方围岩的节理裂隙发育情况;(2)隧道开挖在掌子面前方造成的扰动范围大致为1.5倍的隧道开挖跨度;(3)隧道接近前方变化地质区域时,挤出位移的增大或减小具有超前性;(4)软岩段长度在一定范围内会影响掌子面进入软岩区后挤出位移的大小和变化趋势;(5)硬岩与软岩间的刚度比越大,挤出位移变化速率越大,且隧道由软岩区向硬岩区掘进时挤出位移的变化时机越早,而由硬岩区向软岩区掘进时的变化时机不受刚度比影响;(6)可将对挤出位移的监测分析作为超前地质预报的补充手段判断掌子面前方围岩情况。
[Abstract]:In order to study the extrusion displacement characteristics of soft surrounding rock tunnel face and leading core soil, the extrusion displacement of F215 structural fracture zone of Mai-Yu high-speed Qishan tunnel was measured by GMD sliding micrometer produced by Solexperts AG. Through a series of numerical tests carried out by finite difference program, the variation characteristics of extrusion displacement during tunnel passing through soft surrounding rock are studied emphatically. The influence of fracture zone length and stiffness ratio of hard and soft rock is analyzed. The results show that the size of extrusion displacement can reflect the mass of surrounding rock in front. The distribution of extrusion displacement in the leading core soil can reflect the development of joints and fissures in the surrounding rock in front of the tunnel. When the tunnel excavation has a disturbance range of 1.5 times in front of the face of the tunnel and the excavation span is about 1.5 times, the tunnel is close to the changing geological area in front of the tunnel. When the extrusion displacement increases or decreases, the length of the soft rock segment in a certain range will affect the magnitude and variation trend of the extrusion displacement after the face of the face enters the soft rock area. The greater the stiffness ratio between the hard rock and the soft rock, the greater the change rate of the extrusion displacement. And the earlier the time of extrusion displacement changes when tunneling from soft rock area to hard rock area, However, the time of change from hard rock area to soft rock area is not affected by stiffness ratio.) the monitoring and analysis of extrusion displacement can be used as a supplementary method to judge the surrounding rock condition in front of the face of the face.
【作者单位】：长安大学公路学院;福建省高速公路建设总指挥部;莆田湄渝高速公路有限责任公司;北京城建设计发展集团股份有限公司;
【基金】：国家自然科学基金面上项目(No.51478044);国家自然科学基金面上项目(No.51678062)~~
【分类号】：U456

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