摘要
为了更加科学地预测水平冻结法隧道施工引起的地表竖向位移,从冻结管周围土体与地层冻胀相互作用机理和试验现象出发,提出了冻结管周围冻结土体在地层约束作用下的2种不同冻胀模式;基于热传导理论得到了冻结锋面随时间变化的移动规律,进一步联合镜像法和叠加原理,推导了均匀冻胀模式和非均匀冻胀模式下水平冻结法隧道施工时多个冻结管共同引起的地表竖向位移时空预测计算公式,并依托MATLAB软件编制了求解程序。结合工程实例,将理论解与实测数据进行了对比,此外,还针对隧道埋深、冻结壁厚度、不均匀冻胀性进行了参数影响分析。研究结果表明:不同冻胀模式计算得到的位移分布规律与实测值在整体趋势上基本相似,且实测值介于均匀冻胀模式和非均匀冻胀模式所得理论值之间,证明了所提理论模型的合理性;均匀冻胀模式与非均匀冻胀模式计算得到的地表最大竖向位移均出现在隧道中心正上方地表位置处,但不同冻胀模式下的隧道中心正上方地表竖向位移峰值有明显差异;当其他参数相同时,隧道埋深越浅,地表冻胀位移分布越窄而高,土体冻胀模式对地表位移分布影响越大;冻结壁越厚,地表竖向位移越大;不均匀冻胀程度常数越大,地表竖向最大位移也越大。建议根据工程具体情况,选用所提出的不同冻胀模式来预测水平冻结隧道施工引起的地表变形,以确保工程安全稳定。
To predict the ground vertical displacement caused by horizontal freezing tunnel construction more scientifically, based on the frost heave interaction mechanism and experimental phenomenon between the soil around the freezing pipe and stratum, two different frost heave modes of the frozen soil around the freezing pipe under the constraint of the stratum are proposed in this study. The movement law of the frozen front with time was obtained according to the heat conduction theory. Further, the uniform and non-uniform frost heave modes were deduced by combining the image method and superposition principle. The space-time prediction formula for the ground vertical displacement caused by multiple freezing pipes in the construction of a horizontal freezing tunnel was developed using MATLAB software. In combination with an engineering example, the theoretical solution was compared with the measured data. Moreover, the influence of the parameters on the tunnel buried depth, frozen wall thickness, and uneven frost heave was analyzed. The results demonstrated that the displacement distribution law calculated by different frost heave modes is basically similar to the measured value in the overall trend, and the measured value is between the theoretical value of the uniform and non-uniform frost heave modes, which proves the rationality of the proposed theoretical model. Furthermore, the maximum vertical displacement calculated by the uniform and non-uniform frost heave modes appears in the center of the tunnel. However, the vertical displacement peak value of the ground surface above the tunnel center under different frost heave modes is differs significantly. When the other parameters are the same and the tunnel is buried shallower, the surface frost heave displacement distribution is narrower and higher;the influence of the soil frost heave mode on the surface displacement distribution is greater;the frozen wall is thicker;the vertical displacement of the surface is larger;the constant of the uneven frost heave degree is larger;and the maximum vertical displacement of the surface is higher. To ensure the safe and stable implementation of the project according to the specific situation, different frost heave modes are proposed in this paper to predict the ground deformation caused by the construction of a horizontal freezing tunnel.
作者
董建华
吴晓磊
师利君
DONG Jian-hua;WU Xiao-lei;SHI Li-jun(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,Gansu,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2021年第5期144-155,共12页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51778275)
陇原青年创新创业人才(团队)项目(2020RCXM120)
兰州市十大科技创新项目(2020-2-11)
甘肃省知识产权局高价值专利培育和转化项目(20ZSCQ034)
甘肃省基础研究创新群体项目(20JR10RA205)。
关键词
隧道工程
冻胀模式
镜像法
水平冻结隧道
地表竖向位移
tunnel engineering
frost heave mode
image method
horizontal frozen tunnel
vertical displacement of surface
