Scholarlink

<p>The backfill soil mass exhibits low strength and poor stability, and it is prone to muddification and softening upon exposed to water. When a tunnel traverses such a stratum, the risk of collapse becomes even more pronounced under rainfall conditions. Based on the ultra-shallow buried section of a tunnel through loose accumulation, the method of combining field investigation, theoretical analysis, model test and field monitoring is used to study the deformation and instability mechanism of the surrounding rock under rainfall conditions in ultra-shallow buried backfill soil tunnels. Additionally, support optimization measures are evaluated, and field tests are conducted at the engineering site. The results show that: (1) The backfill soil demonstrates high water sensitivity, with its cohesion being significantly influenced by the water content. When the water content is 10%, cohesion is 47.4&#xa0;kPa, but drops by 95% at 16% water content. (2) Based on the variation principle of rock deformation with different water contents, the process of rock deformation is categorized into five stages. The water content of the instability limit of the surrounding rock is determined, and the water content of 17.6% is taken as the early warning value for the control of the water content of the ultra-shallow buried backfill tunnel. (3) Field monitoring indicates that, after implementing optimized excavation steps and steel arch support measures, the deformation control rate of surrounding rock exceeds 75%. The displacement around the tunnel remains within permissible limits, and the supporting structure maintains a stable operational state.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Analysis and Control Techniques of Ultra-Shallow Buried Tunnels in Rain-Affected Backfill Soil

  • 期刊论文

  • 发表日期：

    2025年6月29日

查看全文
  • Peng-cheng Wang,
  • Li-yang Su,
  • Shu-jie Shang,
  • Xiang-yu Jia,
  • Wei-teng Li,
  • Feng-chuan Jiang,
  • Chun-qing Liu,
  • Xin-jie Man

摘要

The backfill soil mass exhibits low strength and poor stability, and it is prone to muddification and softening upon exposed to water. When a tunnel traverses such a stratum, the risk of collapse becomes even more pronounced under rainfall conditions. Based on the ultra-shallow buried section of a tunnel through loose accumulation, the method of combining field investigation, theoretical analysis, model test and field monitoring is used to study the deformation and instability mechanism of the surrounding rock under rainfall conditions in ultra-shallow buried backfill soil tunnels. Additionally, support optimization measures are evaluated, and field tests are conducted at the engineering site. The results show that: (1) The backfill soil demonstrates high water sensitivity, with its cohesion being significantly influenced by the water content. When the water content is 10%, cohesion is 47.4 kPa, but drops by 95% at 16% water content. (2) Based on the variation principle of rock deformation with different water contents, the process of rock deformation is categorized into five stages. The water content of the instability limit of the surrounding rock is determined, and the water content of 17.6% is taken as the early warning value for the control of the water content of the ultra-shallow buried backfill tunnel. (3) Field monitoring indicates that, after implementing optimized excavation steps and steel arch support measures, the deformation control rate of surrounding rock exceeds 75%. The displacement around the tunnel remains within permissible limits, and the supporting structure maintains a stable operational state.