土壤干缩裂缝网络几何特征  

Geometric Characteristics of Shrinkage Crack Network in Soil

作　　者：张展羽[1,2] 王策[1,2] 朱成立[1,2] 朱文渊[1,2] 吴春辉[1,2] 

机构地区：[1]河海大学南方地区高效灌排与农业水土环境教育部重点实验室,江苏南京210098 [2]河海大学水利水电学院,江苏南京210098

出　　处：《地球科学（中国地质大学学报）》2014年第10期1465-1472,共8页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金资助项目(No.51179050);高等学校学科创新引智计划资助(No.B12032);江西省水利科技项目(No.KT201109)

摘　　要：通过室内试验研究了土壤干缩裂缝发育规律,采用数字图像处理技术与AutoCAD测量功能,分析了不同含水率下土壤裂缝网络几何形态特征.结果表明:土壤含水率达到43%时出现裂缝,裂缝骨架长度、周长和面积分别在含水率达到23%、23%、7%时趋于稳定,裂缝平均宽度的发育经历了波动增长、线性增长和稳定3个阶段,并在含水率达到7%时保持不变;裂缝条数与节点数之比随含水率降低而减小,并最终保持在1.67,此结果与收缩块区分散度和裂缝交叉角度分布规律共同表明,裂缝网络形态呈方形正交网络分布趋势,且处于方型网络与"T"型正交网络之间;裂缝平均弯曲度随含水率减小,由1.06减小至1.02并保持恒定,揭示了裂缝整体弯曲程度与不同时期裂缝弯曲的变化规律.An indoor experiment was conducted to investigate the development law of the shrinkage crack network in soil in this study.By application of digital image processing technology and the measurement functions of AutoCAD,geometric characteristics of shrinkage crack network were quantitatively analyzed under different moisture contents.The results show that the crack first was initiated when the moisture content was 43%.The length of crack skeleton and crack perimeter began to stabilize once the moisture content was close to 23%,and so did the crack ratio at the moisture content of 7%.The average width of the crack developed in three stages,namely,fluctuation growth,linear growth and stabilization,which reached a stable value as the moisture content came to 7%.The ratio of the crack fragments and intersections decreased as the moisture contents became lower and remained stable at 1.67 ultimately,which,together with dispersity of the aggregate and frequency distribution of intersection angles,revealed the square network distribution trend of the crack network.The mean tortuosity of the crack was reduced from 1.06 to 1.02 with the moisture content dropped and stabilized at 1.02,which indicates the whole tortuosity of the cracks and the variation law of the crack tortuosity during different periods.

关 键 词：土壤 裂缝 网络 几何特征 土壤测试 

分 类 号：S152.4[农业科学—土壤学]