季节冻土区梯形混凝土衬砌渠道冻胀预测研究

依据热传导和质量迁移理论,建立渠基冻土温度场、水分场和应力场耦合数学模型,分析了影响季节冻土区渠基土体冻结的核心因素温度和水分运移量,提出以冻结期渠基土体温度和水分迁移量为变量,建立渠基土体冻深和冻胀量预测模型。借助于季节性冻融条件下梯形混凝土衬砌渠道原型观测成果,观测了冻结期渠基以下5 cm处土体温度以及水分迁移量,研究了季节冻融渠基温度和水分运移及其诱发的冻深发展和冻胀变形的变化。经检验,预测曲线与实测曲线基本一致,且满足误差要求,用冻结期土体温度和水分迁移量来预测冻深、冻胀的方法准确可行。

Study on frost heaving prediction of trapezoidal concrete lined canal in seasonal frozen soil region

In accordance with the theories of heat conduction and mass transfer，a coupled math-model of the soil temperature field，moisture field and stress field of canal foundation frozen soil is established，and then the key factors，i.e. temperature and water transfer amount，of the impacts on the soil freezing of the canal foundation in seasonal frozen soil region are analyzed； from which it is proposed to establish a model for predicting both the frozen depth and the frost heaving of canal foundation soil by taking the temperature and water transfer amount of canal foundation soil as the variables. By means of the result from the prototype observation made on the trapezoidal concrete lined canal under the condition of seasonal freezing-thawing，the temperature and water transfer amount 5 cm below the canal foundation in freezing season is observed，while the temperature and water transfer of the canal foundation under the seasonal freezing-thawing as well as the frozen depth development and the change of frost heaving induced by them are studied as well. Through the relevant verification，the predicting curve basically coincides with that from the prototype observation，which can not only meet the error requirement，but can also prove that it is accurate and feasible to predict frozen depth and frost heaving with the soil temperature and water transfer amount during freezing period.