复杂地质条件下隧道围岩大变形负泊松比锚索主动支护方法及控制效果研究

Study on active support method and control effect of NPR anchor cables for large deformation of tunnel surrounding rock under complex geological conditions

隧道工程在建设过程中面临复杂地质条件时发生围岩大变形灾害造成大量经济损失与人员安全威胁。为解决复杂地质条件下隧道围岩大变形灾害难控制的工程问题,首先以开挖补偿法为基础,利用岩石力学方法,说明高支护力主动支护方法是控制围岩大变形的有效手段。然后,针对高支护力主动支护方法对于高性能新材料的需求,介绍团队研发的具有高恒阻力、大变形特性的多世代NPR(negative Poisson’s ratio)新材料。最后,介绍以NPR新材料为核心的主动支护方法在工程应用中对于不同复杂地质条件下的隧道围岩大变形灾害的控制。结果表明:(1)隧道围岩大变形主要由于隧道开挖造成围岩应力重分布导致围岩大变形破坏,而通过主动支护提供支护力可恢复或接近初始应力状态;(2)团队研发的NPR新材料较传统材料不同,可为深部围岩提供足够的支护力以恢复原岩应力状态;(3)根据工程案例分析,NPR主动支护技术在软岩隧道、断层破碎带隧道以及岩爆隧道中均表现出良好的大变形控制效果,为未来复杂地质条件下围岩大变形提供参考依据和实践基础。

Tunnel engineering faces complex geological conditions in the construction process,and the surrounding rock large deformation disasters cause many economic losses and personnel safety threats.Given the challenging issue of controlling the large deformation disaster of tunnel surrounding rock under complex geological conditions,firstly,based on the excavation compensation method,it is presented that the active support method with high support force effectively controls the large deformation of surrounding rock by the rock mechanics method.Secondly,in response to the demand for high support force active support methods for high-performance new materials,multi-generation NPR(negative Poisson¢s ratio)materials with high constant resistance and large deformation characteristics developed by our team are introduced.Finally,the active support method with NPR new material as the core is introduced in engineering applications to control large deformation disasters of tunnel surrounding rock under complex geological conditions.The results indicate that:(1)Large deformation in the tunnel surrounding rock is mainly caused by the redistribution of stress resulting from tunnel excavation,and active support can provide support force to restore or approach the initial stress state.(2)Unlike traditional materials,the NPR new material developed by our team can provide high support force for deep surrounding rock to restore the original stress state.(3)Based on the analysis of engineering cases,the NPR active support technology has demonstrated effective control of large deformations in soft rock tunnels,fault-fracture zone tunnels,and rock burst tunnels,providing a reference and practical basis for dealing with large deformations in complex geological conditions.