基于水热变化的渠基冻土单轴抗压强度试验研究  

Experimental Study on Uniaxial Compressive Strength of Canal Foundation Frozen Soil Based on Hydrothermal Changes

作　　者：万开唯 王斌[1,2,3] Wan Kaiwei;Wang Bin(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,Ningxia;Engineering Research Center of Ministry of Education for Efficient Utilization of Water Resources in Modern Agriculture in Dry Areas,Yinchuan 750021,Ningxia;Ningxia Water Saving Irrigation and Water Resources Regulation Engineering Technology Research Center,Yinchuan 750021,Ningxia)

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

出　　处：《陕西水利》2023年第2期143-145,151,共4页Shaanxi Water Resources

基　　金：宁夏重点研发项目(引才专项)(2018BEB04026);宁夏高等学校一流学科建设项目(NXYLXK2021A03)。

摘　　要：在季节性冻土地区,由于渠基土温度和含水率的差异,所引起的不均匀冻胀导致衬砌渠道破坏,严重影响了灌溉水利用效率。采用试验及统计拟合方法,针对不同温度及初始含水率的渠基冻土试样进行单轴抗压强度试验,分析冻土的应力—应变关系及力学性能,并对渠基土在冻胀过程中的力学性能提出基于温度、水分变化的预测模型。结果表明,渠基冻土的抗压强度随着含水率上升而增长,同时25%~35%含水率的冻土单轴抗压下塑性变形明显,峰值强度不显著;冻结温度和冻土的抗压强度呈线性关系,温度降低,冻土强度增长;低初始含水率(<15%)和接近冻结温度的冻土抗压强度最低。In seasonally frozen soil areas,uneven frost heave caused by the difference of temperature and moisture content of canal foundation soil leads to the destruction of lined canals,which seriously affects the efficiency of irrigation water use.The uniaxial compressive strength test is carried out for the frozen soil samples of canal foundation at different temperatures and initial moisture content by using test and statistical fitting methods to analyze the stress-strain relationship and mechanical properties of the frozen soil.A prediction model based on temperature and moisture changes is proposed for the mechanical properties of canal foundation soil in the process of frost heaving.The results show that the compressive strength of frozen soil in canal foundation increases with the increase of water content,and the plastic deformation of frozen soil with 25%~35%water content under uniaxial compression is obvious,while the peak strength is not significant;There is a linear relationship between freezing temperature and compressive strength of frozen soil.When the temperature decreases,the strength of frozen soil increases;The compressive strength of frozen soil with low initial moisture content(<15%)and near freezing temperature is the lowest.

关 键 词：衬砌渠基 含水率 温度 人工冻土 力学性能 

分 类 号：TU43[建筑科学—岩土工程]