摘要
为了提高隧道施工过程中开挖面及围岩的稳定性,超前加固措施得到了广泛应用,而如何正确评价围岩加固后的力学特性对隧道围岩稳定性判别和支护结构设计是极其重要的。为研究超前加固条件下隧道围岩的力学行为,将深埋圆形隧道简化为静水压力作用下的平面应变模型,引入等效加固区来体现超前加固的效果,提出了考虑超前加固的隧道围岩力学分析模型。基于广义Hoek-Brown屈服准则和非关联流动法则,在对塑性区可能的分布情况进行分析的基础上,对全断面加固方式下围岩位移、应力和塑性区半径进行了理论推导,通过与实测值和数值计算结果进行对比,验证了该文方法的正确性和合理性,并通过与传统方法进行比较,进一步探讨了该文公式在支护设计中的工程意义。研究表明,该文计算结果与实测值和数值计算结果基本吻合,且在指导支护设计时比传统方法更具优越性。该文研究成果更好地反映了超前加固措施对于围岩的作用效果,为超前加固的定量化设计提供理论依据,研究成果可为全断面加固方式下隧道工程的支护设计及安全性评价提供参考。
In order to guarantee the stability of excavation face and surrounding rock in a construction process, ground reinforcement measures have been widely used, and how to properly evaluate the mechanical properties of the surrounding rock under the action of reinforcement is very important to tunnel design and to stability analysis. To investigate the mechanical behavior of tunnels under the effect of ground reinforcement, the deep buried circular tunnel is simplified as a plane strain model. The equivalent reinforced region is introduced to present the strengthening of ground mechanical property. Taking the ground reinforcement into consideration, a mechanical analytical model of tunnel surrounding rock is proposed. Based on the generalized Hoek-Brown yield criterion and non-associated flow rule, the displacement, stress and plastic zone radius of surrounding rock are derived in the presence of full-face type ground reinforcement, by analyzing the possible distribution of plastic zone. The validity and rationality of the method is verified by comparing with the in-situ measured value and numerical results, and the engineering significance of this formula in the design of support is further discussed by comparing with the traditional method. The results of the study show that the calculation results agree with the in-situ measured value and numerical results, and it is more advantageous than the traditional method in guiding the design of the support. The results of this paper better reflect the effect of ground reinforcement measures on the surrounding rock, providing a theoretical basis for the quantitative design of advanced reinforcement, thus providing a reference for tunnel design and safety evaluation under full-face reinforcement.
出处
《工程力学》
EI
CSCD
北大核心
2018年第2期92-104,共13页
Engineering Mechanics
基金
国家自然科学基金重点项目(U1234210)
北京市交通行业科技项目(北京轨道交通运营隧道结构安全检测与评估方法研究)
