隧道风氧化带软弱围岩应力演化及变形机制  

Evolution on the pressure and deformation mechanism of weak surrounding rock in the wind oxidation zone during tunnel excavation

作　　者：莫小兵 臧熙玮 陈啸峰 田振威 邹俊鹏 MO Xiaobing;ZANG Xiwei;CHEN Xiaofeng;TIAN Zhenwei;ZOU Junpeng(China Railway Kunming Construction Investment Co.,Ltd.,Kunming 650500,China;Institute of Geological Survey,China University of Geosciences(Wuhan),Wuhan 430074,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中铁开发投资集团有限公司,云南昆明650500 [2]中国地质大学(武汉)地质调查研究院,湖北武汉430074 [3]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《安全与环境工程》2024年第6期75-82,90,共9页Safety and Environmental Engineering

基　　金：国家自然科学基金面上项目(42177152)。

摘　　要：我国重大隧道工程建设正处于高峰期,我国已成为世界上隧道建设数量、规模和难度最大的国家,而隧道软弱围岩大变形机制是制约我国实现交通强国战略目标的重要科技难题之一。以甘肃马坞梁隧道工程为例,基于原位监测和数值模拟技术,对隧道风氧化带段软弱围岩变形机制进行了研究。通过在隧道的围岩-初期支护、初期支护-二次衬砌部位布设原位监测点,并建立大角度穿过风氧化带的双洞隧道数值模型,研究了隧道围岩不同部位的应力演化特征。结果显示:隧道开挖后,隧道围岩与支护结构间应力呈现初期快速增长、中期缓慢增长、后期逐渐稳定的趋势;隧道软弱围岩的应力分布具有极强的时空效应,风氧化带段软弱围岩在隧道掘进扰动条件下与衬砌的相互作用逐渐减弱;不同软弱围岩段(砂质板岩段和风氧化带段)围岩变形特征及应力分布呈现出明显不同的演变规律。研究成果可为国内同类型软弱围岩隧道掘进提供参考。The construction of major tunnel projects in China is at its peak.China has become the country with the largest number,scale and difficulty of tunnel construction in the world.The large deformation mechanism of tunnel weak surrounding rock is one of the important scientific and technological problems that restrict China’s realization of the strategic goal of a strong transportation country.In this paper,taking Gansu Mawuliang tunnel project as an example,based on in-situ monitoring and numerical simulation technology,the deformation mechanism of weak surrounding rock in tunnel wind oxidation zone is studied.By setting up in-situ monitoring points at the surrounding rock-primary support and primary support-secondary lining parts of the tunnel,and establishing a numerical model of the double-hole tunnel passing through the wind oxidation zone at a large angle,the stress evolution characteristics of different parts of the tunnel surrounding rock are studied.The results show that after the tunnel excavation,the pressure between the surrounding rock and the supporting structure of the tunnel shows a trend of rapid growth in the early stage,slow growth in the middle stage and gradual stability in the later stage.The stress distribution of the weak surrounding rock of the tunnel has a strong time-space effect,and the interaction between the surrounding rock and the lining of the surrounding rock in the wind oxidation zone is gradually weakened under the condition of tunnel excavation disturbance.The deformation characteristics and pressure distribution of surrounding rock in different weak surrounding rock sections(sandy slate section and wind oxidation zone section)show obviously different evolution laws.The research results can provide reference support for the same type of weak surrounding rock tunnel excavation in China.

关 键 词：软弱围岩 原位监测 数值模拟 围岩变形 围岩应力 

分 类 号：X948[环境科学与工程—安全科学] U45[建筑科学—桥梁与隧道工程]