宁夏衬砌渠道渠基冻胀率水热响应试验研究  

Experimental Study on Hydrothermal Response of Frost Swelling Rate of Canal Foundation in Ningxia

作　　者：王羽岱 王斌[1,2,3] 苗福生[1] 马楠 WANG Yu-dai;WANG Bin;MIAO Fu-sheng;MA Nan(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;The Engineering Research Center of the Ministry of Education for Efficient Utilization of Modern Agricultural Water Resources in Arid Areas,Yinchuan 750021,China;Ningxia Water-saving Irrigation and Water Resource Regulation Engineering Technology Research Center,Yinchuan 750021,China)

机构地区：[1]宁夏大学土木与水利工程学院,银川750021 [2]旱区现代农业水资源高效利用教育部工程研究中心,银川750021 [3]宁夏节水灌溉与水资源调控工程技术研究中心,银川750021

出　　处：《节水灌溉》2024年第6期27-34,共8页Water Saving Irrigation

基　　金：宁夏自然科学基金项目(2022AAC03090);宁夏重点研发(引才专项)基金项目(2020BEB04031);宁夏高等学校一流学科建设基金项目(NXYLXK2021A03)。

摘　　要：衬砌渠道周围的水分与温度场分布存在明显差异,此范围内渠基土在水热两场耦合作用下冻胀有明显不同。基于这种差异,开展渠基土在不同水分、温度条件下冻胀率试验研究。结果表明:在不同温度条件下,土体冻胀率随温度的变化过程可分为2个阶段,当温度从0℃降至-5℃左右时,在此阶段产生的冻胀率约占整个冻胀过程的50%~80%,冻胀率与温度线性关系明显。随着温度继续降低,2者非线性关系明显。在无补水情况下,相同温度条件下的土体,初始含水率越大,所产生的冻胀率越大;初始含水率25%和35%的土体产生的冻胀率均为初始含水率15%土体的1倍到2倍以上。当土体在冻胀过程中有水分补充时,其冻胀率与水分变化线性关系明显,初始含水率越大的土体产生的冻胀率增量越大,初始含水率25%、35%的土体冻胀率增量均为15%土体的2倍以上。提出的水热耦合条件与渠基土冻胀率的多元非线性关系与试验数据吻合较好。建立数值模拟模型,对衬砌渠道不同位置处冻胀作用分布与变形进行计算与分析,结果表明:温度越低、水分越大,衬砌渠道所受到的切向冻胀力与法向冻胀力越大。水热变化差异越大时,土体冻胀导致的衬砌渠道冻胀变形越显著。There are distinct variations in the distribution of moisture and temperature fields around the lined channel,and the freezing and expansion rates of the channel base soil in this range under the coupling of water and heat fields are obviously different.To investigate these differences,experimental studies on the freezing and expansion rate of the soil in different moisture and temperature conditions were carried out.The results show that:Under different sub-zero temperature conditions,the freezing expansion rate of the specimens exhibits a two-stage change process.When the temperature is reduced from 0℃to-5℃or so,in this stage of the freezing expansion rate accounts for about 50%to 80%of the whole freezing expansion process,showing a clear linear relationship with temperature.In the second stage,as the temperature continues to decrease,the nonlinear relationship between the two is obvious.Under the condition of no water supplement and same sub-zero temperature conditions,specimens with higher initial moisture content exhibit greater rates of freezing expansion.Initial moisture content of 25%and 35%of the specimen produced frost expansion rate is about double to more than twice the initial moisture content of 15%specimen.When the specimen is replenished with water during the freezing process,the linear relationship between the freezing expansion rate and the moisture change is evident.The larger the initial moisture content of the specimen produces a larger increment of the freezing expansion rate,the initial moisture content of 25%,35%of the specimen freezing expansion rate increment is more than twice as much as the 15%of the specimen.The multivariate nonlinear relationship between hydrothermal coupling conditions and the freezing and expansion rate of canal subsoil was proposed,and it was in good agreement with the experimental data.A numerical simulation model was established to calculate and analyze the distribution and deformation of frost heave in different positions of lining channels.The results show

关 键 词：衬砌渠道 渠基土 温度 含水率 水热耦合 冻胀率 

分 类 号：S277[农业科学—农业水土工程]