中文摘要：

采用SS-1型土壤收缩仪测定崩岗体不同层次原状土壤的收缩特征曲线,研究崩岗土壤收缩特性的空间变异性。结果表明：脱水过程中崩岗土壤的线缩率呈现先增大后稳定的趋势,Logistic模型可以较好地拟合线缩率与含水率间的关系（R^2〉0.991 1）,红土层与斑纹层的土壤收缩曲线分段现象明显,而砂土层则变化平缓,土壤质地越黏重线缩率越大;崩岗不同层次土壤的收缩特性差异显著,红土层与斑纹层的径向收缩应变大于轴向收缩应变,在干燥过程中易产生张拉裂隙,砂土层则相反,在干燥过程中易发生表面下沉。相关性分析表明,径向收缩应变与砂粒含量有极显著的负相关关系（r=-0.933）,而轴向收缩应变受土壤质地影响不明显,体积收缩应变和缩限与黏粒和砂粒分别呈显著正相关（r=0.891）和负相关关系（r=-0.838）,说明崩岗土体收缩过程受土壤质地及土壤基质吸力的综合影响。

英文摘要：

Soil shrinkage curves of different depths in slope disintegration profiles were measured using soil shrinkage tester（ SS-1 type） to investigate the spatial variability of soil shrinkage characteristics. Results showed that in the process of dehydration,soil linear shrinkage ratio displayed increase firstly and then attained to steady level. The relationship between linear shrinkage ratio and water content can be fitted well by the Logistic model. Soil shrinkage curves of red soil layer and speckle soil layer could be apparently divided into three stages. The variation rate in soil linear shrinkage ratio showed an unimodal trend with the decreasing of soil water content,which was not suited to that of sandy soil layer. Linear shrinkage ratio increased when soil texture changed to heavy. Significant difference was found in shrinkage characteristic between different layers of slope disintegration body. Radial shrinkage strain was larger than axial shrinkage strain for red soil layer and speckle soil layer but it was opposite for sandy soil layer,which indicated that horizontal cracks mainly occurred in surface layer during the soil dryness dynamic process. Correlation analysis showed that radial shrinkage strain was negatively correlated with sand content（ r =- 0. 933）;volume shrinkage strain and shrinkage limit were significantly correlated with clay content positively（ r =0. 891） and sand content negatively（ r =- 0. 838）,which indicated that soil shrinkage process was influenced by both soil texture and soil water state. Measures could be taken to reduce drastic variation of soil water content to prevent damage from shrinkage behavior in slope stability.