极高地应力软岩挤压变形特征及支护结构工作性态分析

极高地应力软岩变形速率快、累积大、持续久并在时空上表现出不均匀、不对称等特性,造成隧道开挖支护难、结构体系弱化、失效等工程问题。依托兰新二线大梁隧道建设,针对极高地应力挤压性软岩开展了大量原位试验、围岩量测、数值仿真及设计变更工作,分析了围岩—支护发生的一系列与时间相关的力学行为及动力响应,突破岩体结构及支护变形特征的静态认识,提出适应于该地层的变形控制和支护设计方法,确保软岩掘进工期及安全,为同类工程的建设和研究提供借鉴和参考。

Analysis of the Extra-High Squeezing Deformation Characteristics of Soft Rock and the Mechanical Behavior of Supports Under Extra-HilL Ground Stress

Being high in speed, large in accumulation and long in duration, the deformation of soft rock under extra-high ground stress has the characteristics of being uneven, unsymmetrical in time-space, etc. , which often make the excavation and support- ing of tunnels difficult, and result in the weakening, or even failure of the structural system and other engineering problems. With the construction of the Daliang Tunnel of the second line of the Lanzhou-Xinjiang Railway as ε practical example, much re- search is made of a large number of in-suit tests, the deformation measurement of surrounding rock, numerical simulations and design alteration,with a series of time-related mechanical behavior and the dynamic response during the supporting of the surrounding rock analyzed, the research on which surpasses the static realization of the deformation characteristics of the struc- ture of the rock body and supporting. Besides, some new methods on deformation control and suppcrting design are put forward for the stratum to ensure the soft-rock-boring engineering schedule and safety. The paper may serve as a useful reference for the construction of and research on other similar projects in the future.