锚固体系作用下隧道围岩力学响应的全过程解析

ANALYSIS OF THE WHOLE-PROCESS MECHANICAL RESPONSE OF TUNNEL SURROUNDING ROCK UNDER THE EFFECT OF ANCHORAGE SYSTEM

  • 摘要: 隧道锚固体系是围岩变形控制的重要手段,而对其作用机理的准确认识则是其科学设计的关键。为了探究隧道锚固体系作用下围岩响应的全过程演化规律,该文基于隧道开挖面空间效应,考虑隧道锚杆与锚索先后施作时围岩位移释放情况以及二者相对长度的影响效应,并根据锚固体系与围岩相互作用过程中锚固区与塑性区的空间位态关系,建立了锚固体系全过程演化机制的6种工况分析模型并分别进行了解析,得到了锚固体系作用下围岩变形、塑性区半径以及应力场的全过程解答。通过典型算例与数值模拟进行对比,验证了所提出模型的合理性和可靠性。进一步分析了锚固体系的变形控制效果及其影响因素,阐明了锚杆与锚索支护各自的任务和目标,明确了锚索的安全储备作用,对锚固体系的变形控制原理给出了全新的认识。研究成果为隧道锚固体系的定量化设计奠定了一定的理论基础,可为隧道围岩大变形控制提供思路。

     

    Abstract: The tunnel anchoring system is an important means to control the deformation of surrounding rock, whose scientific design lies in the full understanding of its mechanism. In this paper, the whole process of the response of tunnel surrounding rock with the action of the anchorage system is analyzed. Based on the space effect of the tunnel face, the displacement releases of surrounding rock at bolt and anchor cable installation and the effect of their relative lengths are considered. According to the relationship between the anchorage zone and the plastic zone of the interaction between the anchorage system and the surrounding rock, six mechanical analytical models of the whole process evolution mechanism of anchorage system are proposed and analyzed respectively. The solutions of tunnel deformation, plastic radius and stress field of surrounding rock under the action of anchoring system are obtained. The correctness and reliability of the proposed model are verified through a comparison with numerical simulations using typical examples. Furthermore, the deformation control effect of the anchorage system and its influencing factors are analyzed, and the respective tasks and objectives of rockbolts and anchor cables are defined. The safety reserve function of anchor cable is clarified, giving a new understanding of deformation control principle of anchorage system. The research results lay a theoretical foundation for the quantitative design of tunnel anchorage system and provide a new idea for the control of large deformation of tunnel surrounding rock.

     

/

返回文章
返回