富水红砂岩地层隧道联络通道冻结温度场分布规律及其敏感性分析*

为了明确富水红砂岩地层中冻结温度场的影响因素，研究温度场的发展和分布规律，以兰州地铁2号线定西路站到五里铺站之间的隧道联络通道为研究背景，建立三维瞬态温度场有限元模型对冻结加固过程进行模拟，通过数值模拟和实测数据对比验证模型的准确性进而分析土体密度、导热系数、比热容的变化对温度场发展的影响。通过灰色关联分析法，得到各土体参数对温度场发展的影响程度。研究结果表明:冻结孔越密集，形成的冻结帷幕越厚，冻结壁温度越低；随着导热系数增大，形成的冻结壁温度降低，随着土体密度和比热容增大，形成的冻结壁温度升高；影响温度场温度的各参数灰色关联度排序为:比热容>密度>导热系数；当各参数分别增大30%时，温度场温度变化程度排序为:密度>导热系数>比热容。研究结果可为类似地质冻结工程的设计施工及土体改良提供参考依据。

Distribution law and sensitivity analysis of freezing temperature field in connecting channel of tunnel in water-rich red sandstone stratum

In order to clarify the factors influencing the freezing temperature field in the water-rich red sandstone stratum and study the development and distribution law of temperature field,taking the freezing method construction of Dingxi Road-Wulipu station tunnel connecting channel in Lanzhou Metro Line 2 as the research background,a finite element model of three-dimensional transient temperature field was established to simulate the freezing reinforcement process,and the accuracy of the model was verified by comparing the numerical results with the measured data.On this basis,the influence of soil parameters on the temperature field development under different soil densities,thermal conductivity and specific heat capacities was analyzed.Finally,the influence degree of each factor on the development of temperature field was obtained by the grey correlation analysis.The results showed that the denser the freezing holes,the thicker the formed freezing curtain,and the lower the freezing wall temperature.The higher the thermal conductivity was,the lower the freezing wall temperature was,while the higher the soil density and specific heat capacity were,the higher the freezing wall temperature was.Based on the grey relational analysis,the order of grey relational degree of the influencing factors of temperature field was specific heat capacity > density > thermal conductivity.When each parameter increased by 30%,the order of temperature field variation with parameter change was density > thermal conductivity > specific heat capacity.This study can provide a reference for the design and construction of similar geological freezing projects and soil improvement.