【作者】 夏振尧； 许文年； 谈云志； 陈芳清；

【Author】 XIA Zhen-yao;XU Wen-nian;TAN Yun-zhi;CHEN Fang-qing;Collaborative Innovation Center for Geo-hazards and Eco-Environment in Three Gorges Area;Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,China Three Gorges University;

【机构】 三峡地区地质灾害与生态环境湖北省协同创新中心； 三峡大学三峡库区生态环境教育部工程研究中心；

【摘要】 Wu&Waldron等学者建立的根系增大土壤抗剪强度的力学模型中,根系加筋贡献系数(K值)以一常数简化,这种方法在预测草本植物的加筋作用时被广泛利用。大量试验表明,根土复合体抗剪强度的实测值往往小于W&W模型中的计算值,主要原因是根系加筋贡献系数取值(1.2)有失严谨。论文在W&W模型的假设条件下,从土体的内摩擦角、剪切面上根系的初始分布角度及变化、根系破坏时的剪切变形角3个因素对根系加筋贡献系数进行了敏感性分析。将土体剪切面上根系分为初始压缩态和初始拉伸态两类根系,综合分析了这两类根系对固土的贡献,结果认为对于大部分土体,根系固土作用贡献系数通常为小于1的值。基于以上分析,可计算得出不同土体内摩擦角条件下根系加筋贡献系数的均值,为根系加筋固土效应的预测提供更为准确的计算参数。更多还原

【Abstract】 The mechanical model of root enhancing soil’s shear strength established by Wu and Waldron,in what the rootreinforcement factor is simplified as a constant,is widely used to calculate the soil reinforcement due to roots of herbaceous plant.Mass of in suit test indicated that the actual measurement value of soil-root composite material’s shear strength is usually less than the calculated value upon Wu & Waldron models,for the reason of adopting the value(1.2)of root-reinforcement factor inaccuracy.In assumed condition of Wu & Waldron models,this paper takes sensitivity analysis of root-reinforcement factor by three determinants of soil friction angle,initial root orientation and variation relative to the failure plane and angle of the root at rupture relative to initial orientation.It analyses the reinforcement contribution of two kinds of roots,which can be defined as initial pressure state and initial tension state,and the result shows that the root-reinforcement factor is usually less than 1 to most soil.Based on these analysis,the average value of root-reinforcement factors can be calculated and obtained in condition of different soil friction angle,what could offer a more accurate parameter for estimating the effect of root reinforce soil.更多还原