层状岩体的广泛分布是地下工程无法回避的现实。以渝湘高速公路共和隧道为工程背景,采用自行研制的弹脆性模型相似材料,制作出层状岩体隧道模型。采用大型真三轴岩土工程模型试验机进行加载试验,采用围岩应变监测、洞室内窥摄影、试件破坏形态的研究与分析,从而对缓倾角层理岩体中隧道的二次应力分布特征及破坏机制进行研究。试验中还通过超载系数,提供了一个安全储备的定量评估指标。试验的破坏特征与隧道实际破坏一致,说明了模型试验的正确性,同时也为顺层偏压隧道的加固机制研究及加固设计提供了试验基础。
Wide contribution of layered rockmass cannot be avoided in underground construction. Based on the Gonghe tunnel in Yuxiang Highway a physical model for layered rockmass is made adopting elastobrittle simulated material which is developed independently. Loading through the large scale real triaxial geotechnical engineering testing machine, the configuration trait of secondary stress and failure mechanisms of layered rockmass ttmnel with low inclination angle are presented. Various failure mechanisms present in various place via the strain in surrounding rock, inner video and failure configuration around the tunnel. The test provides a quantitative evaluating index for safety storage with overload coefficient. The failure in the test is consistent with the practical tunnel which validates the anisotropic model and provides a foundation for the research on reinforcing mechanism and reinforcing design of tunnels in layered anisotropy rockmass.