深埋隧道层状岩体破坏过程特征模型试验

针对深埋隧道层状岩体围岩变形破坏的复杂性,以渝沙高速公路共和隧道工程为背景,采用自行研制的弹脆性相似材料构筑层状岩体隧道物理模型,利用应变监测技术和内窥摄影技术,研究了层状岩体在不同荷载作用下围岩应力分布及变形破坏过程特征。结果表明：深部层状岩体受层理结构面的影响,围岩具有明显偏压特征;在沿层理面方向主要受到与其一致的应力挤压从而产生剪切破坏,垂直于层理方向的破坏呈X型裂纹且沿洞壁深部发展;掉落块体呈楔型体,隧道围岩破坏范围呈明显的不均现象;模型试验结果与现场测试结果基本一致,为理论分析深部层状岩体破坏机理提供了可靠的试验结果。

Model Test for Characteristics of Failure Process of Layered Rock Mass in Deep Buried Tunnel

Owing to the complexity of deformation and destruction of layered surrounding rock mass in deep buried tunnel,the stress distribution and the deformation and destruction feature of surrounding rock of Gonghe Tunnel in Yusha Expressway were investigated under different loads with the self-made physical layered rock tunnel model constructed by elastic-brittle analogy material and the technology of strain monitoring and endoscope photography.Results show that the surrounding rock has the obvious bias characteristic influenced by bedding structure of layered rock in deep position.The shear failure is extruded by the stress along the bedding structure.If the surrounding rock is perpendicular to the bedding,the damage is in X type.The cracks develop along the deep position of tunnel wall and the falling rock mass is in wedge type.The damage contour of surrounding rock shows obvious bias characteristic.The test results and the field results are basically consistent.It provides reliable experimental result for theoretical analysis on the failure mechanism of layered rock mass in deep position.