【摘要】 研究目的：白云岩砂化作为一种特殊岩溶现象，富水环境下具有强致灾性。为了揭示富水砂化白云岩地层隧道突涌致灾成因，提供控制对策，本文以成昆铁路扩能工程峨眉至米易段吉新隧道为依托工程，对隧道突涌事故进行调研，结合区域地质、室内微观观测手段以及物理力学试验，对白云岩砂化成因进行分析，总结砂化白云岩灾变模式与致灾成因，并提出控制措施。研究结论：（1）区域白云岩砂化机制为渗透-溶蚀分解-机械崩解型，地层中分布的富水砂化囊体是造成隧道突涌的灾害源；（2）砂化白云岩以细颗粒为主，均匀性差，遇水抗剪强度显著衰减，隧道突涌破坏模式可以分为揭示渗透破坏型突涌、渐进破坏型突涌与间歇型突涌；（3）提出灾害源识别、灾害源释水降压、灾害源加固、低扰动开挖的施工控制对策；（4）本研究成果可应用于砂化白云岩地层隧道突水突泥灾害的治理。更多还原

【Abstract】 Research purposes: Dolomite sanding is a special karst phenomenon, which is highly disaster-causing in water-rich environments. To reveal the cause of disaster caused by tunnel surge in water-rich sanded dolomite stratum, the control measures are provided. Based on the Jixin Tunnel from the Emei to Miyi section of the Chengdu-Kunming Railway capacity expansion project, this paper investigates the tunnel surge accident, analyzes the formation causes of white cloud sand by combining regional geology, indoor microscopic observation methods, and physical and mechanical tests, summarizes the disaster mode and causes of sanded dolomite, and puts forward control measures. Research conclusions:(1) The regional dolomite sanding mechanism is a permeation-dissolution decomposition mechanical disintegration type, and the water-rich sanding sacs distributed in the formation are the disaster source of tunnel gushing.(2) Sanded dolomite is dominated by fine particles, poor uniformity, and significantly attenuated shear strength in water. Tunnel surge failure modes can be divided into penetration-type surge, progressive surge, and intermittent surge.(3) The disaster source identification, disaster source water pressure reduction, disaster source reinforcement, low disturbance excavation construction control countermeasures are proposed.(4) The research results can be applied to the control of tunnel water outburst disasters in sanded dolomite formation.更多还原