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。 In order to study the extrusion displacement characteristics of the face and leading core of soft surrounding rock tunnels, the displacement of F215 structural fracture zone in the Meishan high-speed Qishan tunnel was measured by the GMD sliding micrometer manufactured by Solexperts AG. Differential program, a series of numerical experiments are carried out. The variation characteristics of extrusion displacement during tunneling through weak surrounding rock are emphatically studied, and the influence of fracture zone length and stiffness ratio of hard and soft rock is analyzed. The results show that (1) the size of extrusion displacement can reflect the quality of the surrounding rock mass, and the distribution of extrusion displacement in the advanced core soil can reflect the development of the jointed rock in front of the surrounding rock. (2) (3) When the tunnel is near the front of the geological area, the increase or decrease of the extrusion displacement is advanced; (4) The length of the soft rock section will be within a certain range (5) The greater the stiffness ratio between hard rock and soft rock, the greater the rate of change of extrusion displacement, and the tunnel from soft rock to hard rock The earlier the timing of the change of extrusion displacement during excavation is, and the timing of the change from hard rock to the soft rock excavation is not affected by the stiffness ratio. (6) The monitoring and analysis of extrusion displacement can be used as a supplement to advance geological prediction Means to judge the surrounding rock face in front of the situation.