高温冻土区U型块石路基长期降温效果及变形特征研究

发布时间：2018-02-16 04:48

本文关键词： U型块石路基青藏铁路高温冻土降温效果路基变形　出处：《岩土力学》2017年11期 　论文类型：期刊论文

【摘要】：U型块石路基作为块石护坡与块石基底两种结构路基的组合,同时也作为青藏铁路的一种主要补强措施,其在高温冻土区的长期降温效果备受关注。基于长期的现场监测资料,对青藏铁路楚玛尔河高温冻土区一处U型块石路基的长期降温过程、降温机制以及变形特征进行了研究。结果表明:U型块石路基表现出持续稳定的降温效果,路基下部多年冻土上限附近降温明显,上限抬升迅速,且进入稳定状态。基底块石层底、顶板温差存在明显冷暖季差异。阴坡侧块石层每年1月至3月初为相对强烈自然对流期,阳坡侧相对缩短半个月时间。受工程热扰动影响,深层的多年冻土在经历2~3年升温过程后,呈现显著的降温过程。路基变形整体表现为较小的沉降量,变形主要来源于早期路基下部高温冻土层的压缩变形。总之,U型块石路基在高温冻土区表现出长期有效的降温效果,变形量有限且已趋于稳定,路基整体稳定性可以得到保证。
[Abstract]:As a combination of two kinds of structural subgrade of block rock slope protection and block stone base, U-shaped rock block roadbed is also a main reinforcement measure of Qinghai-Tibet Railway, and its long-term cooling effect in high temperature frozen soil area has attracted much attention. Based on long-term field monitoring data, the U type block stone subgrade is a kind of main reinforcement measure of Qinghai-Tibet Railway. In this paper, the long-term cooling process, cooling mechanism and deformation characteristics of a U-shaped rock roadbed in the Chumar River permafrost region of the Qinghai-Tibet Railway are studied. The results show that the U shaped block roadbed shows a continuous and stable cooling effect. The upper limit of permafrost in the lower part of the roadbed is obviously cooled, the upper limit is raised rapidly, and it is in a stable state. The difference of roof temperature between cold and warm season is obvious. The rock layer of shady slope side is a relatively strong natural convection period from January to early March of each year, and the sunny slope side is relatively shortened for half a month, which is affected by engineering thermal disturbance. After 2 ~ 3 years of heating, the deep permafrost shows a significant cooling process, and the subgrade deformation shows a relatively small settlement as a whole. The deformation mainly comes from the compression deformation of the high temperature frozen soil in the lower part of the early roadbed. In a word, the U-shaped block roadbed shows a long-term effective cooling effect in the high temperature frozen soil area, the deformation amount is limited and tends to be stable, and the overall stability of the roadbed can be guaranteed.
【作者单位】：中国科学院西北生态环境资源研究院冻土工程国家重点实验室;
【基金】：国家自然科学基金项目(No.41630636,No.41701067) 中国博士后科学基金项目(No.2017M610662)~~
【分类号】：U416.1

【相似文献】