石匣小流域整地措施对土壤剪切性质的影响  

Effects of Engineering Measures on Soil Shear Characteristics in Shixia Small Watershed

作　　者：潘欣[1,2] 王云琦[1,2] 高勇 宋伯岩 朱楠[1,2] 歌丽巴 

机构地区：[1]北京林业大学水土保持与荒漠化防治教育部重点实验室,北京100083 [2]北京林业大学北京市水土保持工程技术研究中心,北京100083 [3]密云县水土保持工作站,北京101500

出　　处：《水土保持学报》2016年第6期314-318,共5页Journal of Soil and Water Conservation

基　　金：国家林业公益性行业科研专项"基于生态安全的水土保持措施空间配置技术"(201404209);北京市教育委共建项目"北京山区生态风险监测与评估技术研究"

摘　　要：为了解坡面整地措施对坡体稳定性的影响和土壤物理性质对土壤抗剪强度的差异性,选取石匣小流域4个标准样地,通过测量多个土壤物理性质指标(土壤容重、土壤含水率、总孔隙度、毛管孔隙度、非毛管孔隙度、紧实度和液限),研究不同坡面整地措施的土壤临界剪切力随深度的变化,以及土壤抗剪切破坏能力的强弱关系和影响因素。结果表明:原状土的临界剪切力随深度的增加而增加;通过库伦公式得出的土壤抗剪强度与土壤临界剪切力的回归方程为σ=0.0123τf+0.6308。土壤物理性质对抗剪强度的影响不同,紧实度、容重与含水率对抗剪强度的影响相对较大。对于不同的坡面整地措施,土壤抗剪切能力强弱顺序为梯田>水平条>裸地,其中,在水平条上种植针叶树,土壤抗剪切能力优于种植阔叶树。在北京石匣地区,布设坡面整地措施时,需因地制宜地增加田面宽度,并种植针阔混交林以增加土壤抗剪强度。Shixia Basin is located at north of Miyun Reservoir,which is the first level nature reserve as well as an important water source of Beijing area,but suffering from serious soil erosion and debris flow.Slope engineering measures may decrease soil loss of the slope,accumulate aggregates,and increase slope stability.Terrace and horizontal bar are two kinds of engineering measures well adopted in Beijing area.To investigate the effects of engineering measures on slop stability,and understand the effects of soil physical properties（soil bulk density,soil moisture,total porosity,capillary porosity,non-capillary porosity,firmness and liquid limit）on soil shear strength,the changes of soil shear force with depth under different engineering measures,soil shear characteristics and the affecting factors were studied.The results showed that soil critical shear force increased with soil depth.The relationship between soil shear strength calculated by Coulomb formula and soil critical shear force measured in situ fitted with the equation：σ=0.0123τf＋0.6308.Cohesion and angle of internal friction on and down the channel of irrigation differed slightly,but shear strength differed significantly.The effects of soil physical characteristics varied,among which soil compaction,volume-weight and moisture content had the most significant effects.The anti-shear ability ranked as follows：terrace〉horizontal bars〉bare land,and the anti-shear ability of the horizontal bars with conifer was better than the one with deciduous trees.In the area of Miyun,Beijing,when carrying out engineering measures,it is important to increase the width of terrace,and establish mingled forest of conifers and deciduous trees.

关 键 词：土壤剪切力 土壤抗剪强度 土壤物理性质 

分 类 号：S157.2[农业科学—土壤学]