【作者】 陆海红；

【导师】 赵树德； 王铁行；

【作者基本信息】 西安建筑科技大学 ， 岩土工程， 2003， 硕士

【摘要】 在国内外有关非饱和土温度场、水分迁移场及其耦合问题研究的基础上，给出了考虑辐射、蒸发、风速等边界条件的温度场有限元方程，给出了计算饱和-非饱和土水分迁移场的有限元方程，对非饱和黄土中温度场和水分迁移场传输机理及其耦合问题进行了初步的研究，给出了土体温度场和水分迁移场之间耦合问题的有限元计算模式，分析了温度和含水量之间的相互作用和影响。分别对不同温度梯度、不同密实度、不同初始含水量的土样进行试验，测定了各个土样中含水量的分布。基于对实验资料的分析，可以得出：温度对含水量分布的影响是在温度作用下含水量沿长度方向不是均值的，而是变化的，冷端的含水量增大，热端的含水量减少；初始含水量对含水量分布的影响是当初始含水量较大和较小时，温度差引起的含水量差值均较小，当初始含水量适中时，温度差引起的含水量差值较大，但含水量梯度与初始含水量的比值与初始含水量成反比；密实度对含水量分布的影响是密实度越小的土样其含水量的变化越大。通过对实验结果的分析，给出了反映温度和含水量之间关系的线性回归方程。在确定含水量的分布以后，考虑各类边界条件的影响计算有限元方程得到温度场的分布。由温度场的分布可以得到：在温度梯度的作用下，导热系数是变化的，而导热系数沿长度方向的变化，使得稳态温度场沿长度方向成非线性分布；密实度对温度场分布的影响是干密度越大导热系数越大；初始含水量对温度场分布的影响是含水量增大，导热系数也增大，达到最大值后，含水量增加导热系数反而减少，含水量对温度场的分布有显著的影响。更多还原

【Abstract】 On the basis of the existing researches about the fully coupled thermal field and moisture movement in unsarurated loess soils, this paper gives the finite element module of thermal field after consideration of various natural elements such as wind speed, radiation, evaporation, and meanwhile put forwards the finite element module of moisture movement on saturated-unsaturated loess soils. Furthermore, The paper also probes into the thermal and moisture transferring and coupled theory, and gives finite element module of fully coupled thermal field and moisture movement in unsarurated loess soils. Taking the unsarurated loess soil sample, the water content distribution of the soil with various density and moisture content is tested in various thermal gradients. The test data indicates that the water content distribution of the soil sample changes obviously after taking a thermal gradient on the soil. The water content in the soil with lower temperature is added, and with higher temperature is lowed. The water content gradient of the soil is related to the soil water content and density and temperature gradient. The more is the temperature gradient, and the less is the soil density, the more is the water content gradient. If the soil water content is gradually added from very little value, the value of water content gradient resulted from temperature gradient first is lower, then bigger and finally lower. Based on the test data, a linear regression equation about temperature and water content is got. After deciding the temperature and moisture distribution of the soil samples, the problem of coupled thermal and moisture is discussed, the temperature distributions show that the heat-conducting coefficient is related to the density and water content. The more is the density, the more is the heat-conducting coefficient .If the soil water content is gradually added from very little value, the heat-conducting coefficient first is lower, then bigger and finally lower.更多还原