基于广义Hoek-Brown准则的深埋硐室围岩塑性区位移分析

Analysis on rock plastic zone displacement of deep buried underground chamber based on generalized Hoek-Brown criterion

将广义的Hoek-Brown准则采用无量纲量形式进行表示,在此基础上,建立了均匀应力场圆形硐室的弹塑性解析方法。并针对不同性质岩体,分为不考虑岩体剪胀和塑性区内的弹性变形、考虑岩体剪胀且塑性区内的弹性变形为常量、考虑岩体剪胀且塑性区内的弹性变形为变量这3种情况,对深埋硐室围岩的塑性区位移进行了对比分析。分析结果表明:在考虑岩体剪胀且塑性区内的弹性变形为变量情况下,硐室围岩塑性区位移的计算结果最大。对于岩体质量差和一般的软岩硐室,应考虑岩体的剪胀特性和塑性区内的弹性变形,且塑性区内的弹性变形应为变量;而对于岩体质量好的硐室或者是硬岩硐室,则不必考虑岩体的剪胀特性和塑性区内的弹性变形。

Generalized Hoek-Brown criterion is indicated as a dimensionless quantity; on this basis, elasto-plastic analytical method of circular underground chamber in uniform stress field has been established. According to the following three kinds of circumstances： 1） without considering rock dilatancy and elastic deformation in plastic zone, 2） considering rock dilatancy and constant elastic deformation in plastic zone, 3） considering rock dilatancy and varied elastic deformation in plastic zone, surrounding rock plastic zone displacement of deep buried underground chamber has been comparatively analyzed for different quality rock mass. The results have shown that surrounding rock plastic zone displacement is the maximum under the circumstance of considering rock dilatancy and varied elastic deformation in plastic zone. For soft rock chamber in poor and average quality rock mass, rock dilatancy and varied elastic deformation in plastic zone must be considered in the process of analysis on surrounding rock plastic zone displacement. For chamber in good quality rock mass or hard rock chamber, rock dilatancy and elastic deformation in plastic zone may not have to be considered.