干旱地区植被根系在增强土体抗剪强度方面具有显著作用.为探究塔里木河下游植物根系对岸坡土体抗剪强度的影响,明确植被对岸坡防护的作用机理,以红柳、芦苇、骆驼刺、梭梭 4 种典型荒漠植被为例,开展室内根系拉伸试验和直接剪切试验,对比分析了 4 种植物根系对土体抗剪强度的影响规律.结果表明,4种根系的直径与抗拉力和抗拉强度均呈幂函数关系,其中与抗拉力呈正相关,与抗拉强度呈负相关,当根系直径>1.5 mm 后抗拉力差异性显著提高;根系体积密度(RRVD)对根—复合体的抗剪强度影响呈非线性.4 种根—土复合体增加相同RRVD 时,对抗剪强度的提高程度依次为红柳>芦苇>骆驼刺>梭梭,表明红柳和芦苇在提高抗拉力和土体粘聚力方面具有显著优势,可作为沿岸固土防蚀植被推广种植.
Influence of Different Plant Roots on Shear Strength of Bank Slope Soil
This study focused on four typical desert vegetation species:tamarisk,reed,camelthorn,and saltcedar,to investigate the impact of plant root systems on the shear strength of slope soils in the downstream area of the Tarim River and to elucidate the mechanisms by which vegetation contributed to slope protection.Indoor root tensile tests and direct shear tests were conducted to analyze the influence of these four plant root systems on soil shear strength.The results in-dicate that the diameters of the four root systems exhibit a power-law relationship with both tensile force and tensile strength.Specifically,they are positively correlated with tensile force and negatively correlated with tensile strength.These differences in tensile force become significantly more pronounced when root diameters exceed 1.5 mm.Moreover,the impact of root volume density(RRVD)on the shear strength of the root-soil complex appears a nonlinear pattern.When the four root-soil complexes increase(RRVD)by the same amount,the degree of improvement in shear strength follows this sequence:tamarisk>reed>camelthorn>saltcedar.These results indicate that red willow and reed have signifi-cant advantages in improving the tensile strength and soil cohesiveness,and can be widely planted as soil consolidation and erosion prevention vegetation along the riverfront.
万方数据
维普
