摘要
在高地应力条件下具有层理构造的软岩中开挖隧道后,软弱围岩会发生显著的蠕变变形,直接影响隧道围岩的稳定性及支护结构的长期服役性能。本文采用有限元方法分析了兰渝铁路木寨岭隧道深埋软岩段双层和三层衬砌支护的效果。结果表明:在初期支护和二次衬砌之间增设轻质混凝土缓冲层有利于隧道围岩应力和变形的调整,可有效降低支护结构受力,从而充分发挥二层衬砌与锚杆的长期支护作用,更适用于高地应力条件下长期流变特征明显的软岩段隧道支护。
Under high geo-stress condition,signif icant creep deformation of weak surrounding rock occurs after tunnel excavation in soft rock with bedding structure,which directly affect the stability of tunnel surrounding rock and long-term service performance of the supporting structure.The supporting effect of the double lining support and the three-layer lining support was analyzed for deep buried soft rock section of the Muzhailing tunnel in Lanzhou-Chongqin railway by using the f inite element method.The results show that addition of lightweight concrete buffer layer between the initial support and the secondary lining is good to the adjustment of stress and deformation of tunnel surrounding rock,which can effectively reduce the stress of the supporting structure,give full play to the long-term support of the double lining and anchor rod,and is more suitable for tunnel support in soft rock section with obvious long-term rheological characteristics under high geo-stress condition.
作者
张海洋
徐文杰
王永刚
ZHANG Haiyang;XU Wenjie;WANG Yonggang(CNNC Key laboratory on Geological Disposal Technology of High-level Radioactive Waste,Beijing Research Institute of Uranium Geology,Beijing 100029,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;Gansu Province Transportation Planning,Survey&Design Institute Co.Ltd.,Lanzhou Gansu 730030,China)
出处
《铁道建筑》
北大核心
2018年第8期71-74,共4页
Railway Engineering
基金
国家自然科学基金(41702344)
关键词
铁路隧道
支护方案
数值计算
软岩蠕变
各向异性
轻质混凝土
软弱围岩
Railway tunnel
Supporting scheme
Numerical calculation
Soft rock creep
Anisotropy
Lightweight concrete
Weak surrounding rock
