深埋隧道全长黏结锚杆加固等效方法研究

Study on Equivalent Analytical Method for Reinforcement of Full Grouted Anchor Bolt in Deep-buried Tunnel

为定量描述全长黏结锚杆对深埋隧道围岩的加固作用及其对衬砌支护抗力的影响,结合全长黏结锚杆中性点理论改进了等效计算因子,基于Mohr-Coulomb屈服准则推导出施加锚杆后岩体强度参数的解析表达式;基于新奥法围岩衬砌共同承载理念,建立深埋隧道全长黏结锚杆等效加固的力学模型,推导了围岩施加锚杆后等效复合体临界破坏时衬砌结构所需提供的最小支护抗力的表达式。结合工程实例,利用改进的等效计算因子分别计算了施加锚杆后围岩强度参数和支护抗力。结果表明,该等效方法可以有效量化设计方案的支护效果。

In order to describe the reinforcement effect of full grouted anchor bolt on surrounding rock of deep-buried tunnel and its influence on the lining support resistance,the equivalent calculation factor was improved by combining the neutral point theory of full grouted anchor bolt,and analytical expressions for the rock mass strength parameters after applying anchor bolts were derived based on Mohr-Coulomb yield criterion.According to the joint bearing concept of surrounding rock and lining of New Austrian Method,a mechanical model of the equivalent reinforcement of full grouted anchor bolt in deep-buried tunnel was established,and the expression of minimum support resistance required by lining when the critical failure of the equivalent composite body formed after the anchor bolts were applied to the surrounding rock was derived.Combined with the engineering,surrounding rock strength parameter and support resistance after applying anchor bolts were calculated respectively by using the improved equivalent calculation factors.And the results show that the equivalent method can effectively quantify the supporting effect of the design scheme.