【摘要】 用室内三轴试验方法研究了草根加筋土的应力-应变及强度特性,探讨了在不同加筋情况下草根加筋土抗剪强度指标的变化规律,分析了素土和草根加筋土的变形破坏模式以及筋材在土体剪切过程中的阻抗机理。试验结果表明:(1)草根加筋土的强度和抵抗变形的能力较素土有显著的增强;(2)对于抗剪强度指标,与素土相比草根加筋土的内摩擦角变化较小(相对变化率绝对值在11%以内),但黏聚力增长较大(最大可达9倍);(3)在草根加筋层数一定的情况下,随着加筋量的增加,草根加筋土的主应力差值、抗剪强度值以及黏聚力值呈现先增加后降低的趋势,亦即加筋层数相同时存在最佳含根量。本研究结果对于深入认识植被护坡机理和合理选择植被密度具有指导意义。更多还原

【Abstract】 Laboratory triaxial tests were carried out in order to understand the stress-strain relationship and strength property of grassroots-reinforced soil(GRS).The change of shear strength indexes of GRS with the quantity of grassroots planted in the soil samples was investigated.The failure modes of reinforced and unreinforced soils were discussed;and also the frictional mechanism between the grassroots and soil in the shearing process was studied.The laboratory test results show that:(1) the strength and the capacity for resisting the deformation of grassroots-reinforced soil are better than those of unreinforced soil;(2) as to the shear strength indexes of GRS,the change of internal friction angle is small compare to that of unreinforced soil(its absolute value of relative rate of change is less than 11 %);but the cohesion is more larger than that of unreinforced soil(the maximal increased multiple is nearly 9);(3) in the certain number of grassroots layers,the value of deviator stress,shear strength and cohesion first increase and then reduce with the increasing of grassroots quantity,i.e.there is an optimal reinforcement quantity existing in GRS in the given number of grassroots layers.The research results are of importance for understanding the mechanism of vegetation protection for slopes and determining the density of grass planting.更多还原