摘要
以某高海拔寒冷地区软岩公路隧道为研究对象,对处置塌方的方案进行了研究,结果表明,在进行公路围岩的挖掘作业后,需要对其迅速进行相关支护施工作业,一旦支护工作不及时到位,就会导致公路围岩暴露在无支护环境中,从而十分容易产生公路局部塌方、掉块等现象和问题。基于上述问题和现象,提出了三种防治公路塌方现象的方案,并对此分别进行模拟运算,发现在围岩力学条件下,通过使用钢拱架作为隧道围岩的支护工具可以显著降低塌方的发生次数,其所导致的形变量也出现显著减小。进行不同的钢拱架作为围岩的支护工具的比较分析后,发现公路围栏钢拱架之间的距离在不使用其他支护方式的时候不宜大于1.20m。掌子面前方围岩松动可通过超前支护结构有效抑制,在拱腰部位,开挖面和最小主应力在拱顶部位正交或垂直。洞室开挖后,会导致洞室开挖面周围产生不同程度的塑性破坏区域。并且在底板以及拱顶位置所产生的破坏大多数为张拉性破坏,拱脚和拱腰部位主要为剪切破坏。本文的研究,所得到的最佳防治方案为,注浆管的长度为3.55m,纵向间隔距离为1.02m,在其拱部按环向间距为1.52m时进行注浆处理。
Taking a highway tunnel in a high altitude and cold area as the research object,this paper studies the scheme of dealing with the collapse.The results show that the surrounding rock must be supported in time after excavation.If the support is not timely,the surrounding rock is prone to local collapse,falling fast and other disasters without support.Through the simulation calculation of three treatment schemes,the mechanical conditions of surrounding rock are obviously controlled after using steel arch support,and the deformation decreases obviously.By comparing the spacing of different steel arch frames,it is concluded that the spacing of steel arch frames should not be greater than 1.20 m without other supporting measures.The loosening of surrounding rock in front of the palm can be effectively restrained by the advance support structure.At the waist of the arch,the excavation face and the minimum principal stress are orthogonal or vertical at the top of the arch.After the excavation of the cavern,there are different degrees of plastic failure areas near the excavation face.Tensile failure is the main failure in the floor and vault,and shear failure is the main failure in the arch foot and waist.The optimum treatment scheme is that the length of grouting pipe is 3.55 m and the longitudinal distance is 1.02 m.The grouting treatment is carried out at the arch when the circumferential distance is 1.52 m.
作者
任和祥
REN Hexiang(China Railway 25th Bureau Group Co.,Ltd.,Guangzhou,Guangdong 510030,China)
出处
《公路工程》
北大核心
2020年第1期212-216,共5页
Highway Engineering
基金
宁夏自治区科学技术厅课题(2015142)
关键词
公路隧道
处治方案
塌方
软岩
塑性破坏
highway tunnel
treatment scheme
collapse
soft rock
plastic failure
