摘要
为研究落石冲击柔性钢棚洞的力学特性,并优化柔性钢棚洞的结构参数,依托成昆铁路复线老鼻山隧道工程溶洞处理方案中的柔性钢棚洞防护结构,建立有限元数值模拟模型,对落石冲击柔性钢棚洞的力学特性及落石不同冲击角度对柔性钢棚洞的影响进行研究,得到不同条件下落石的位移、速度变化及棚洞的应力变化情况;同时研究不同跨度条件下落石冲击对柔性钢棚洞的影响,并对柔性钢棚洞钢架跨度进行优化。结果表明:落石以不同角度冲击棚洞时,应力集中均出现在H型钢钢拱架拱顶与横向撑杆相接处,施作时应加强该处结构,在以垂直角度冲击棚洞时,对其稳定性影响最大,本工程条件下可保证棚洞安全稳定;钢架跨度越大,棚洞结构越不稳定,但应考虑施工是否方便,综合选用钢架跨度为3 m。
In order to study the mechanical characteristics of rockfall impact flexible steel shed cave and optimize the structural parameters of flexible steel shed cave,this paper established a finite element numerical simulation model based on the protective structure of flexible steel shed cave in the karst cave treatment scheme of Laobishan tunnel project of Chengdu-Kunming Railway double line,and studied the mechanical characteristics of rockfall impact flexible steel shed cave and the influence of different impact angles of rockfall on flexible steel shed cave,and obtained the displacement,velocity change and stress change of the shed cave under different conditions.At the same time,the influence of rockfall impact on flexible steel shed cave under different span conditions was studied,and the span of the steel frame of flexible steel shed cave was optimized.The results show that:when the rockfall hits the shed at different angles,the stress concentration occurs at the junction of the H-shaped steel arch frame vault and the transverse brace,and the structure should be strengthened when it is applied,the stability of the shed cave is the greatest affected when the vertical angle is impacted,and the safety and stability of the shed cave can be ensured under the conditions of this project.The larger the span of the steel frame,the more unstable the structure of the shed cave,but whether the construction is convenient should be considered,and the comprehensive selection of steel frame span is 3 m.
作者
翟耀红
ZHAI Yaohong(China Railway 12th Bureau Group 1st Engineering Co.Ltd.,Xi′an Shaanxi 710038,China)
出处
《铁道建筑技术》
2023年第11期172-175,180,共5页
Railway Construction Technology
基金
中铁十二局集团第一工程有限公司科研项目(公司科[2017]04号)。
关键词
铁路隧道
溶洞治理
数值模拟
柔性棚洞
railway tunnel
karst cave management
numerical simulation
flexible shed cave
