基于Hoek-Brown准则对围岩松动圈半径的推导及改进  

Derivation of the radius of the Broken Rock Zone based on Hoek-Brown criterion and its improvement

作　　者：陈秋南[1] 黄小城[1] 谢小鱼[1] 

机构地区：[1]湖南科技大学土木工程学院411201湘潭

出　　处：《应用力学学报》2015年第2期304-310,357-358,共7页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(41172275)

摘　　要：针对服从Hoek-Brown准则的节理岩体圆形隧道,根据隧道开挖后的围岩分为破裂剧烈区、塑性软化区、弹性区的特点,推导了圆形隧道在轴对称时松动圈半径的表达式。Hoek-Brown准则中扰动参数D表征的是岩体受扰动的程度,而对其如何取值的相关研究较少。为提高所推导围岩松动圈半径表达式的精确性,采用可拓学理论,综合考虑爆破损伤、卸荷影响、岩体完整性指标Kv、围岩级别四个因素来判断岩体受扰动情况,在物元模型的理论基础上得到了扰动参数D的取值方法。最后运用新的岩体扰动参数D得出了围岩松动圈半径解析解,并在现场采用地质雷达对隧道的不同断面进行了实测,得到了不同隧道断面6组围岩松动圈的半径,将实测值与对应的计算值进行对比分析,二者相对误差约为4.5%,验证了本文理论解的正确性。For circular tunnels in jointed rock mass which obeys the Hoek-Brown criterion, the radius of the Broken Rock Zone(BRZ) in circular tunnel is derived based on the character that surrounding rocks can be divided into stable fracture area, violent fracture area and elastic area after tunnel has been excavated. The extent of the rock mass is disturbed can be represented by the disturbed parameter D in Hoek-Brown criterion has been studied by few scholars up to the present. In order to improve the accuracy of the derived expression, the disturbedparameter D can be evaluated based on matter-element model theory by considering the blasting damage, unloading effect, rock mass integrity index Kv and the surrounding rock level form the Extension Theory. An analytical solution of radius of the broken rock zone is calculated, where the new disturbed parameter D is applied. The radius of the Broken Rock Zone in different sections is measured by the in-situ GPR. Six sets of the radius of the Broken Rock Zone in different section are obtained and are compared with the corresponding calculated values, the relative error is about 4.5%, which may verify the exactness of the theoretical solution.

关 键 词：HOEK-BROWN准则 围岩松动圈 可拓理论 物元模型 扰动参数D 

分 类 号：U458[建筑科学—桥梁与隧道工程]