基于Hoek-Brown弹塑性损伤模型的小净距隧道施工优化  

Research on construction optimization of small spacing tunnel based on Hoek-Brown elastoplastic damage model

作　　者：秦伟宏 姜谙男[1] 许梦飞 虢新平 QIN Wei-hong;JIANG An-nan;XU Meng-fei;GUO Xin-ping(Institute of Road and Bridge Engineering,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]大连海事大学道路与桥梁工程研究所,辽宁大连116026

出　　处：《广西大学学报（自然科学版）》2022年第4期843-853,共11页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(52078093);辽宁省兴辽英才项目(XLYC1905015)。

摘　　要：为了确定考虑围岩损伤作用下小净距隧道的合理开挖进尺及中夹岩柱加固方案,以福建苏桥隧道为工程依托,基于Hoek-Brown(H-B)弹塑性损伤模型,对开挖进尺分别为0.5、1.0、1.5、2.0 m工况下小净距隧道施工过程进行模拟,研究了不同开挖进尺下的后行洞LDP曲线及拱腰收敛的变化规律。同时,从围岩损伤的角度对中夹岩柱加固问题展开研究,分析了“对穿锚杆”、“拱腰注浆”、“拱腰-拱肩注浆”和“拱腰-拱肩-拱脚注浆”4种方案,研究围岩损伤值大小、损伤范围和最大主应力的分布规律。结果表明:随着开挖进尺的增加,洞周位移量逐渐增大,在确保安全施工的前提下,为了保证施工进度,现场开挖进尺宜选为1.5 m。由不同加固方案围岩损伤范围、损伤值以及最大主应力的分布规律可以看出,加固效果从强到弱依次是“拱腰-拱肩-拱脚注浆”“拱腰-拱肩注浆”“拱腰注浆”和对穿锚杆,考虑加固成本,宜选用“拱腰-拱肩注浆”的加固方案。基于H-B准则的弹塑性损伤模型和现场监测值拟合较好,并且比一般的H-B弹塑性模型更能表征现场实际位移情况。In order to determine the reasonable excavation footage of the tunnel with small net distance and the reinforcement scheme of the medium rock column under the action of surrounding rock damage, based on the Suqiao tunnel in Fujian province and the Hoek-Brown(H-B) rock elastic-plastic damage model, the excavation footage is 0.5 m and 1.0 m, respectively, the construction process of the tunnel with a small net distance of 1.5 m and 2.0 m was simulated, and the change rule of LDP curve of the back tunnel and arch waist convergence under different excavation footage was studied. At the same time, from the point of view of surrounding rock damage, the reinforcement problem of rock column in the middle was studied, and four kinds of schemes were analyzed, including “through the bolt”, “arch waist grouting”, “arch waist-arch shoulder grouting” and “arch waist-arch shoulder-arch foot grouting”, to study the size of surrounding rock damage value, damage range and distribution law of maximum principal stress. The results show that with the increase of excavation footage, the displacement around the tunnel increases gradually. On the premise of ensuring the safety of construction, in order to ensure the construction progress, the excavation footage should be selected as 1.5 m. By zone of injury, damage of surrounding rock in different reinforcement scheme as well as the maximum principal stress distribution can be seen that the reinforcement effect from strong to weak, in turn, is “hance grouting-spandrel arch foot” hance-spandrel grouting “bolt” hance grouting “and to wear, considering strengthening cost, appropriate chooses” hance-spandrel grouting reinforcement scheme;The elastic-plastic damage model based on H-B criterion fits well with the field monitoring value, and can better characterize the actual displacement in the field than the general H-B elastic-plastic model.

关 键 词：Hoek-Brown弹塑性损伤模型 围岩损伤 开挖进尺 中夹岩柱加固 工程应用 

分 类 号：X951[环境科学与工程—安全科学]