冻土未冻水含量的量热法试验研究  

Experimental research on unfrozen water content of frozen soils by calorimetry

作　　者：冷毅飞[1] 张喜发[1] 杨凤学[2] 姜龙[2] 赵意民[2] 

机构地区：[1]吉林大学建设工程学院,长春130026 [2]大庆油田工程有限公司,黑龙江大庆163712

出　　处：《岩土力学》2010年第12期3758-3764,共7页Rock and Soil Mechanics

摘　　要：冻土未冻水含量不但是评价冻土中水分迁移特性的重要指标,而且也是冻土热工计算中常用的参数。采用未冻水测量方法中的经典量热法对采自中俄石油管道工程大庆-漠河段沿线大兴安岭多年冻土带的6类典型土样(共76个)进行了-0.5、-2、-5、-10℃左右负温下的未冻水含量测试。分析了负温温度t、土质类型和初始含水率wo对未冻水含量wu的影响及其变化规律。通过统计分析,给出了6类土在上述4个给定温度下的未冻水含量代表值及其幂函数wu=at-b方程中的参数值。将黏土、粉质黏土、粉土和泥炭质土各给定温度下的未冻水含量对塑限wp归一化,得到各土类各温度下未冻水量系数值。对其进行幂函数拟合得到wu-wp-t经验计算公式。将温度、土质条件和初始含水率3影响因素进行综合分析,得到各类土在给定温度下的wu-wo-wp关系的二元一次线性回归经验方程式,为实际工程应用提供参考。Unfrozen water content is not only an important evaluation index of water migration in frozen soils, but also a common parameter in thermotechnical calculation. Six types of soil samples （totally 76） which are collected from the permafrost of Da Hingang Mountains on the section of Daqing-Mohe in the China-Russia oil pipeline project are measured by calorimetry at such temperatures as about -0.5 ℃, -2 ℃, -5 ℃ and -10℃. The principle and equipment of calorimetry are introduced firstly. According to a large number of test data, The analyses of the influencing factors and their variations of unfrozen water content, which include temperature, soil type and initial moisture content are made. The representative values of unfrozen water content at four given temperature in the six types of soils are obtained through statistical analysis. The coefficients of unfrozen water contents at different given temperatures are obtained by normalizing the unfrozen water content and plastic limit water content. The empirical formulas for unfrozen water contents in clay, silty clay, silt and peat soil are given through fitting unfrozen water content, plastic limit and temperature with power function. Finally, making comprehensive analysis of temperature, soil condition and initial water content, we get binary linear regression equation on unfrozen water content, initial water content and plastic limit water content, so as to provide reference for actual engineering.

关 键 词：未冻水 量热法 影响因素 经验公式 

分 类 号：TU411[建筑科学—岩土工程]