羊角一号隧道大型半充填溶洞处理措施研究

Discussion on the Treatment Measures of Large-scale Half Filled Karst Cave in Yangjiao No.1 Tunnel

渝黔铁路羊角一号隧道施工中揭示的大型半充填型溶洞具有空间分布差异大、纵向延伸距离长、隧道基底充填物均一性与稳定性差等特点。文章基于溶洞发育特征与工程补勘资料,从施工难度、运营风险、工程投资等多个方面进行了比较分析,最终确定了桩板结构跨越的处理方案。通过结构计算与工程类比对桩板结构进行了详细设计,并根据隧道拱墙部溶腔规模采取了回填或护拱方案,针对不同的基底条件采取钢花管或袖阀管注浆加固的处理措施。工程实践表明,羊角一号隧道大型半充填型溶洞综合处理措施的经济技术效果良好,可供类似工程借鉴参考。

The large half-filled cave revealed in the construction of the Yangjiao No. 1 tunnel of the Chongqing-Qianjiang Railway has the characteristics of large spatial distribution differences, long longitudinal extension, poor uniformity and stability of the tunnel base filling. Based on the karst development characteristics and engineering geological replenishment data, a comparative analysis is made from various aspects such as construction difficulty, operational risk and engineering investment in this paper, and finally the treatment scheme of the pile-plate structure is determined. The pile-plate structure is designed in detail by structural calculation and engineering analogy, the backfilling or protection arching scheme is adopted according to the size of the cavity of the tunnel arch wall, and the treatment measures of steel flower pipe or sleeve valve pipe grouting reinforced are adopted for different substrate conditions. The engineering practice shows that the economic and technical effects of the comprehensive treatment measures for large half-filled cave in Yangjiao No.1 Tunnel are good, which can be used as reference in similar projects.