深层隧道围岩承载能力定量分析方法研究

发布时间：2018-06-17 21:21

本文选题：深层隧道 + 主承载结构　；参考：《湖南大学》2014年硕士论文

【摘要】：地层在开挖后，，形成了一个释放应力，此时围岩承担二次释放应力，是主承载结构。支护加强围岩强度或者承担一部分二次释放应力，是辅承载结构。各种围岩分级方法仅给出围岩承载能力的定性描述，缺乏定量描述，本文结合强度折减法，结合每次折减系数下的应力响应状态提出等效强度的概念，实现了围岩承载能力的定量化。本文提出了各支护手段的力学机理，以及对等效强度的贡献大小，从而将主承载结构与辅承载结构的承载能力进行了具体的计算。最后本文对提高围岩承载能力的各支护方案的承载效果进行了定量分析。 (1)围岩支护结构的计算理论主要经过了刚性结构阶段、弹性结构阶段、连续介质阶段等发展历程，人们对围岩力学作用的认识也经历了围岩仅为荷载来源到围岩本身也是承载结构的转变。在围岩的支护设计方法上，传统的支护设计方法主要是结构力学设计方法，现代的设计方法则强调提高岩体强度以发挥围岩本身的承载能力。 (2)现代支护结构设计原理与方法以新奥法为代表，然而新奥法仍是以围岩分级为基础的经验设计，对于辅承载结构对主承载结构承载能力辅助作用的多少和主次没有给出说明，本文不仅从各辅承载结构的力学机理而且从承载能力定量化上给出具体的计算和说明，并给出了不同辅承载结构承载能力的大小和主次。 (3)依据等效强度的概念，分析了不同支护结构类型对围岩承载能力提高幅度的影响，本文认为，锚杆支护虽然对位移收敛效果不显著，但是极大地提高了围岩的承载能力，钢拱架支护虽然对位移收敛有效果，但是对等效强度的提高效果不显著，建议支护手段以锚杆支护为主。等效强度概念的提出定量地描述了围岩及支护的承载能力，也为支护设计提供了理论上的依据。
[Abstract]:After excavation, a release stress is formed, and the surrounding rock bears the secondary release stress, which is the main bearing structure. Supporting strengthening the strength of surrounding rock or bearing part of secondary release stress is auxiliary bearing structure. All kinds of classification methods only give the qualitative description of the bearing capacity of surrounding rock, but lack of quantitative description. In this paper, combined with the strength reduction method and the stress response state under each reduction coefficient, the concept of equivalent strength is put forward. The quantitative analysis of the bearing capacity of surrounding rock is realized. In this paper, the mechanical mechanism of each supporting method and its contribution to the equivalent strength are put forward, so the bearing capacity of the main bearing structure and the auxiliary bearing structure are calculated concretely. Finally, the paper makes a quantitative analysis on the bearing effect of various supporting schemes to improve the bearing capacity of surrounding rock. 1) the calculation theory of surrounding rock supporting structure mainly goes through rigid structure stage and elastic structure stage. During the development of continuous medium stage, people's understanding of the mechanical function of surrounding rock has also experienced the transformation from the source of the surrounding rock to the bearing structure of the surrounding rock itself. In support design method of surrounding rock, the traditional support design method is mainly structural mechanics design method. The modern design method emphasizes the enhancement of rock mass strength in order to give full play to the bearing capacity of surrounding rock itself. (2) the design principle and method of modern supporting structure is represented by the New Austrian method, but the new Austrian method is still an empirical design based on the classification of surrounding rock. In this paper, not only from the mechanical mechanism of each auxiliary bearing structure, but also from the quantitative analysis of the bearing capacity of the auxiliary bearing structure, the concrete calculation and explanation are given. According to the concept of equivalent strength, the influence of different types of supporting structure on the increase of surrounding rock bearing capacity is analyzed. Although the effect of bolt support on displacement convergence is not significant, the bearing capacity of surrounding rock is greatly improved. Although steel arch support has effect on displacement convergence, the effect of improving equivalent strength is not significant. It is suggested that bolt support should be the main support method. The concept of equivalent strength describes quantitatively the bearing capacity of surrounding rock and support, and provides a theoretical basis for the design of support.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2

【参考文献】