摘要
为解决国家兰海高速(G75)定西段岷县隧道在建设过程中原支护设计方案出现的软岩大变形问题,通过软岩类型分析、围岩变形力学机制分析,提出针对不同力学机制的力学转化对策,引入在矿山及边坡等岩石领域广泛应用的高预紧力恒阻大变形锚索,提出了“超前支护+长短NPR锚索优化布置主动支护+钢拱架+混凝土喷浆永久支护”的高预应力主被动联合支护技术。通过数值模拟和现场监测效果对比研究,结果表明,现场试验段围岩最大变形量仅为73 mm,恒阻大变形锚索的预紧力均在280~300 kN范围内,可见优化后不同支护技术均对围岩变形起到了控制作用,有效发挥了恒阻让压支护的作用,控制效果明显。
In response to the significant soft rock deformation challenges encountered during the construction of the Minxian Tunnel along the Lanzhou-Haikou Expressway(G75),this study conducted a comprehensive analysis of soft rock types and the underlying mechanical mechanisms governing the deformation of the surrounding rock.It presented tailored mechanical transformation strategies to address diverse mechanical mechanisms.Also,it introduced the application of anchor cable with high pre-tightening force,constant resistance and large deformation,a proven solution widely employed in mining and rock engineering.Furthermore,the research proposed a high-prestress and active and passive combined support technique,encompassing pre-reinforced retaining structure,optimally arranged active retaining structure with long and short NPR anchor cables,steel arches,and permanent retaining structure of shotcrete.By implementing numerical simulations and on-site monitoring,the results demonstrated a remarkable reduction in the maximum deformation of the surrounding rock in the test section to only 73 mm,and the pre-tightening forces applied to the anchor cable with constant resistance and large deformation ranged from 280 to 300 kN,underscoring the effectiveness of the optimized retaining technique in controlling surrounding rock deformation.This research highlights the pivotal role of retaining structure with constant resistance and yielding support,which significantly improves deformation control.
作者
王智佼
谢迪
范晋琰
毛玉铤
陶志刚
WANG Zhijiao;XIE Di;FAN Jinyan;MAO Yuting;TAO Zhigang(Gansu Changda Road Industry Co.,Ltd,Lanzhou 730030,Gansu,China;State Key Laboratory of Deep Geotechnical Mechanics and Underground Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Building Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Huayuan International Land Port Group Co.,Ltd,Taiyuan 030001,Shanxi,China)
出处
《地质力学学报》
CSCD
北大核心
2023年第5期648-661,共14页
Journal of Geomechanics
基金
深部岩土力学与地下工程国家重点实验室创新基金项目(SKLGDUEK202201)。
关键词
隧道工程
炭质板岩
联合支护
数值模拟
现场监测
tunnel engineering
carbonaceous slate
combined retaining structure
numerical simulation
onsite monitoring
