Study on the Ultimate Plastic Failure of Tunnels in Layered Rock Masses under High In-Situ Stress Based on Full-Section Conditions

The mechanism of rock mass failure at the face of high geostress tunnels and the ultra-strength support measures are among the most problems in tunnel engineering.Meanwhile, excavating tunnels in weak surrounding rocks is also a difficult issue, and scholars both domestically and internationally have conducted extensive research on problem.However, the stability of tunnels excavated in alternating soft and hard rock masses still needs systematic and in-depth analysis.The main reason is that in highostress areas, the dynamic response of alternating soft and hard rocks after tunnel excavation is different.The full-face method of construction can reduce the disturbance to the surrounding, which is beneficial for tunnel excavation under these conditions.