摘要
以某隧道V级围岩试验段为工程背景,采用现场测试和数值分析手段,对比支护形式进行基于黏弹塑性的三维变形、受力分析,获取了锚杆、喷射混凝土及钢支撑等初期支护结构的受力特征以及围岩变形规律。分析表明:在云母片岩地层隧道中,大变形主要表现为剪切破坏特征,3种支护形式对围岩的变形都有一定控制作用,但顶部系统锚杆对控制塑性区的影响作用甚微;锚杆及其他初期支护受力最大的区域均位于边墙下部和拱脚位置,提高喷层厚度和钢架刚度能减缓变形速率,但过大的刚度也使得结构内力大大增加。因此,为控制云母片岩隧道过度变形,应增强边墙与锁脚锚杆以提高初期支护成环效应,适当的提高钢架的刚度,必要时提前施作二次衬砌。
Taking the test section of V-class surrounding rock mass of a tunnel as the research object, by using field test and numerical analysis, the 3D viscoelastic-plastic deformations and stresses under 3 support schemes are comparatively analysed, the mechanical characteristics of primary support such as anchoring bolt, shotcrete, steel frame, and the deformation regularity of the surrounding rock are obtained. The result shows that （ 1 ） to the tunnel in mica schist, the large deformation is mainly shear failure, and the 3 support schemes can control the deformation of surrounding rock to certain extent, but the top anchoring bolts have little effect in controlling the plastic zone; （2） the largest stress areas of anchoring bolts and other primary supports are located at the lower part of side wall and arch foot, improving the shotcrete layer thickness and the steel frame stiffness can reduce deformation rate, but excessive stiffness also makes the structure internal force greatly increased. Therefore, in order to control excessive deformation of mica schist tunnel, the anchoring bolts of side wall and skewback foundation must be strengthened to improve the annular effect of primary support, the stiffness of steel frame should also be increased appropriately, and applied the secondary lining when necessary.
出处
《公路交通科技》
CAS
CSCD
北大核心
2014年第5期102-108,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(41202201)
中央高校基本科研业务费专项资金项目(CUGL110215)
关键词
隧道工程
支护效应
数值分析
锚杆
云母片岩
tunnel engineering
supporting effect
numerical analysis
anchoring bolt
mica schist
