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Experimental study on the law of water-heat movement of remolded unsaturated loess humidified by steam
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摘要: 为研究非饱和黄土中水蒸气的吸附与运移规律，采用水蒸气对非饱和黄土进行增湿，分析蒸汽压梯度、温度梯度和含水率梯度共同作用下非饱和黄土中水-热运移规律。研究结果表明：在非饱和黄土中，水蒸气和温度的扩散范围近似于一个椭球体。水蒸气在土体中运移时，蒸汽压力沿径向逐渐消散，蒸汽运移速率减缓，土体含水率和温度也逐步降低；当蒸汽气压为0.1 MPa，温度为145 ℃，通气6.5 h后，水蒸气最大增湿半径为80 cm，横向、纵向有效增湿半径分别为60和70 cm；在以通气点为圆心，横向40 cm，纵向50 cm的椭球体内，含水率在12%~17%间变化，接近土体的最优含水率17.08%，增湿效果较好；延长通气时间，增湿范围和增湿程度均将增大；水蒸气增湿时，液态水和气态水迁移共存，但在有效增湿范围内以气态水迁移为主。受到土颗粒的阻碍，沿径向水分运移速率逐渐减小，但温度传导系数在两阶段内接近一个定值。水蒸气增湿法作为土体增湿的新技术与新方法，具有诸多优点，在对土体增湿的工程实践和试验中有着广泛的应用前景。Abstract: In order to study the adsorption and migration of water vapor in remolded unsaturated loess, water vapor was used to humidify unsaturated loess, and the law of water-heat movement in remolded unsaturated loess
under vapor pressure gradient, temperature gradient and water content gradient was analyzed. The results show that the diffusion range of water vapor and temperature is similar to an ellipsoid in unsaturated loess. During the migration of water vapor, the water vapor pressure disappears along the radial direction, the vapor transport rate decreases, and the soil moisture content and temperature also reduce; when the vapor pressure is 0.1 MPa and the temperature is 145 ℃, the maximum humidification radius of water vapor is 80 cm, and the effective humidification radius in horizontal direction is 60 cm and that in vertical directions is 70 cm after 6.5 hours. In the ellipsoid with the point of ventilation as the center, with 40 cm in the horizontal direction and 50 cm in the longitudinal direction, the water content varies between 12% and 17%. The humidification effect is better, the moisture content close to the soil is 17.08% which is the optimum moisture content, the ventilation time is extended, and the humidification range and the humidification degree are increased; when the steam is humidifying, the migration of liquid water and the gaseous water coexist, but the migration of gaseous water is dominant within the effective humidification range. Obstructed by soil particles, the water transport rate decreases gradually along the radial direction, but the temperature conductivity is close to a fixed value in two stages; the steam humidification method is a new technology and a new method for soil humidification. The advantages have broad application prospects in the engineering practice and experiment of soil humidification. -
图 4 通气点正上方各测点温度变化
Figure 4. Temperature change diagram of measuring points right above the ventilation point
图 5 通气点所在平面温度迁移(单位：℃)
Figure 5. Temperature transfer diagram of the ventilation point plane (unit: ℃)
图 6 6.5 h后含水率沿径向变化曲线
Figure 6. Variation curves of moisture content in horizontal direction after 6.5 hours
图 7 奇数层平面内含水率分布
Figure 7. Distribution maps of moisture content in odd number layer planes
图 8 横纵方向导热系数变化
Figure 8. Transverse and longitudinal variation diagram of thermal conductivity
表 1 基本物理指标
Table 1. Indexes of loess properties
含水率/% 密度/(g·cm-3) 最优含水率/% 最大干密度/(g·cm-3) 液限/% 塑限/% 塑性指数 颗粒组成/% ≥0.075 mm 0.005~0.075 mm ≤0.005 mm 7.04 1.53 17.8 1.74 27.1 17.4 9.7 13 65 22 
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[1] 王铁行, 李宁, 谢定义. 土体水热力耦合问题研究意义、现状及建议[J]. 岩土力学,2005,26(3):488-493. (WANG Tiehang, LI Ning, XIE Dingyi. Necessity and means in research on soil coupled heat-moisture-stress issues[J]. Rock and Soil Mechanics, 2005, 26(3): 488-493. (in Chinese) doi: 10.3969/j.issn.1000-7598.2005.03.031 [2] 苑中显, 陈永昌. 工程传热学—基础理论与专题应用[M]. 北京: 科学出版社, 2012: 186-200. YUAN Zhongxian, CHEN Yongchang. Engineering heat transfer: basic theory and special application[M]. Beijing: Science Press, 2012: 186-200. (in Chinese) [3] 刘峰, 朱庆杰, 程雨, 等. 多孔介质热流固耦合问题及研究进展[J]. 岩土力学,2009,30(增刊2):254-256. (LIU Feng, ZHU Qingjie, CHENG Yu, et al. Problems of fluid-solid-heat coupling for porous media and its research progress[J]. Rock and Soil Mechanics, 2009, 30(Suppl2): 254-256. (in Chinese) [4] 陈正汉, 谢定义, 王永胜. 非饱和土的水气运动规律及其工程性质研究[J]. 岩土工程学报,1993,15(3):9-20. (CHEN Zhenghan, XIE Dingyi, WANG Yongsheng. Experimental studies of laws of fluid motion, Suction and pore pressures in unsaturated soil[J]. Chinese Journal of Geotechnical Engineering, 1993, 15(3): 9-20. (in Chinese) doi: 10.3321/j.issn:1000-4548.1993.03.002 [5] 付长静, 李国英, 陈亮, 等. 利用温度场计算渗透流速的数学模型[J]. 水利水运工程学报,2015(6):88-93. (FU Changjing, LI Guoying, CHEN Liang, et al. A mathematical model for calculating penetration velocity using temperature field[J]. Hydro-Science and Engineering, 2015(6): 88-93. (in Chinese) [6] 王志国, 宋明启, 贾永英, 等. 基于不可逆热力学原理的油藏多孔介质耦合作用模型[J]. 工程热物理学报,2014,35(11):2149-2153. (WANG Zhiguo, SONG Mingqi, JIA Yongying, et al. Reservoir porous medium coupling model based on the principle of irreversible thermodynamics[J]. Journal of Engineering Thermophysics, 2014, 35(11): 2149-2153. (in Chinese) [7] 张磊, 郭海庆, 谢兴华, 等. 人工降雨入渗边坡破坏试验研究[J]. 水利水运工程学报,2012(6):21-27. (ZHANG Lei, GUO Haiqing, XIE Xinghua, et al. Experimental study on artificial rainfall infiltration into slope[J]. Hydro-Science and Engineering, 2012(6): 21-27. (in Chinese) doi: 10.3969/j.issn.1009-640X.2012.06.004 [8] 刘伟, 范爱武, 黄晓明. 多孔介质传热传质理论与应用[M]. 北京: 科学出版社, 2006. LIU Wei, FAN Aiwu, HUANG Xiaoming. Theory and application of heat and mass transfer in porous media[M]. Beijing: Science Press, 2006. (in Chinese) [9] 陈武, 董元宏, 李双洋, 等. 季节性冻土区引水暗渠的临界埋深数值分析[J]. 水利水运工程学报,2011(3):65-69. (CHEN Wu, DONG Yuanhong, LI Shuangyang, et al. Numerical analysis of the culvert in seasonally critical buried depth of frozen ground regions[J]. Hydro-Science and Engineering, 2011(3): 65-69. (in Chinese) doi: 10.3969/j.issn.1009-640X.2011.03.010 [10] 袁越锦, 谭礼斌, 徐英英, 等. 颗粒堆积多孔介质干燥多尺度多层结构传热传质模型及模拟[J]. 工程热物理学报,2015,36(12):2726-2729. (YUAN Yuejin, TAN Libin, XU Yingying, et al. Multi-scale and multi-layer structural modeling and simulation of heat and mass transfer processes for drying of grain packing porous media[J]. Journal of Engineering Thermophysics, 2015, 36(12): 2726-2729. (in Chinese) [11] BOUYOUCOS G J. Effects of temperature on movement of water vapor and capillary moisture in soils[J]. Journal of Agricultural Research, 1915, 5(3): 141-171. [12] WANG T H, SU L J. Experimental study on moisture migration in unsaturated loess under effect of temperature[J]. Journal of Cold Regions Engineering, 2010, 24(3): 77-86. doi: 10.1061/(ASCE)CR.1943-5495.0000015 [13] 张仁义, 顾强康, 王乐凡, 等. 干旱地区黄土包气带水分分布规律[J]. 长安大学学报(自然科学版),2014,34(5):37-41. (ZHANG Renyi, GU Qiangkang, WANG Lefan, et al. Moisture distribution of aeration zone of loess in arid region[J]. Journal of Chang’an University (Natural Science Edition), 2014, 34(5): 37-41. (in Chinese) [14] 王铁行, 贺再球, 赵树德, 等. 非饱和土体气态水迁移试验研究[J]. 岩石力学与工程学报,2005,24(18):3271-3275. (WANG Tiehang, HE Zaiqiu, ZHAO Shude, et al. Experimental study on vaporous water transference in loess and sandy soil[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(18): 3271-3275. (in Chinese) doi: 10.3321/j.issn:1000-6915.2005.18.012 [15] 王铁行, 陆海红. 温度影响下的非饱和黄土水分迁移问题探讨[J]. 岩土力学,2004,25(7):1081-1084. (WANG Tiehang, LU Haihong. Moisture migration in unsaturated loess considering temperature effect[J]. Rock and Soil Mechanics, 2004, 25(7): 1081-1084. (in Chinese) doi: 10.3969/j.issn.1000-7598.2004.07.016 [16] 马忙利, 杨波. 黄土增湿方法的试验研究[J]. 陕西地质,2012,30(1):78-81. (MA Mangli, YANG Bo. Experimental study on loess humidification[J]. Geology of Shaanxi, 2012, 30(1): 78-81. (in Chinese) doi: 10.3969/j.issn.1001-6996.2012.01.014 [17] 张登飞, 陈存礼, 杨炯, 等. 侧限条件下增湿时湿陷性黄土的变形及持水特性[J]. 岩石力学与工程学报,2016,35(3):604-612. (ZHANG Dengfei, CHEN Cunli, YANG Jiong, et al. Deformation and water retention behaviour of collapsible loess during wetting under lateral confinement[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(3): 604-612. (in Chinese) [18] 顾强康, 屈波, 张仁义, 等. 硫酸盐渍土定量增湿盐胀特性试验[J]. 长安大学学报(自然科学版),2015,35(3):53-58. (GU Qiangkang, QU Bo, ZHANG Renyi, et al. Salt-heaving characteristics of sulphate saline soil under quantitative humidifying[J]. Journal of Chang'an University (Natural Science Edition), 2015, 35(3): 53-58. (in Chinese) [19] 王铁行, 刘自成, 卢靖. 黄土导热系数和比热容的实验研究[J]. 岩土力学,2007,28(4):655-658. (WANG Tiehang, LIU Zicheng, LU Jing. Experimental study on coefficient of thermal conductivity and specific volume heat of loess[J]. Rock and Soil Mechanics, 2007, 28(4): 655-658. (in Chinese) doi: 10.3969/j.issn.1000-7598.2007.04.004 -
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