坡度对含根坡体稳定性的影响

朱海丽1, 2， 宋 路1， 李国荣1， 胡夏嵩1, 2， 卢海静1， 赵玉娇1

(1.青海大学地质工程系，青海西宁 810016；2. 中国科学院青海盐湖研究所，青海西宁 810008)

摘要为了定量化分析在不同坡度条件下植被根系对边坡稳定性的贡献，采用不固结不排水三轴压缩试验测定研究区不含根土体及2种灌木植物根-土复合体的抗剪强度参数，应用极限平衡法分析不同坡度对边坡稳定性的影响。通过算例分析，发现当坡度在25°以下时，有根系边坡的稳定系数比素土边坡的稳定系数增大1倍以上；当坡度在25°～50°之间时，种植灌木四翅滨藜的边坡稳定性较种植柠条锦鸡儿边坡平均增加38%，其中四翅滨藜可提高边坡稳定系数1.38～0.80，柠条锦鸡儿提高边坡稳定系数在1.03～0.56之间，植物根系对边坡土体发挥着重要的加筋和锚固作用；当边坡坡度超过55°时，2种灌木植物根系对边坡稳定性的影响相对较小。

关键词含根坡体；坡角；根系；稳定系数

中图分类号S181

基金项目国家自然科学

作者简介朱海丽(1977- )，女，江苏溧阳人，副教授，博士，从事边坡生态防护与滨河生态方面的教学与科研。

收稿日期2015-06-16

Influence of Slope Angle on Root Containing Slope Stability

ZHU Hai-li1,2, SONG Lu1, LI Guo-rong1et al (1. Department of Geological Engineering, Qinghai University, Xining, Qinghai 810016; 2. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008)

AbstractIn order to make a quantitative analysis of the contribution of root system on slope stability under the condition of different slope angle, unconsolidated and undrained triaxial compression test were used to measure the shear strength parameters of soil and root-soil composite in the study area, then analyzed the influences of slope angle on slope stability by limit equilibrium method. The results showed that the stability coefficient of root containing slope was higher more than one time than soil slope when the slope angle was lower than 25°. The slope stability of planting Atriplex canescens was average increased 38% than slope of planting Caragana korshinskii when the gradient was range from 25°to 50°. Atriplex canescens and Caragana korshinskii can increase slope stability coefficient 1.38-0.80 and 1.03-0.56 respectively, which indicated that root system have significant roles of reinforcement and anchoring on soil mass. During the slope angle was higher than 55°, the influence of two kinds of shrubs on slope stability was relatively lesser.

Key words Root containing slope; Slope angle; Root system; Stability coefficient

国内外大量研究表明，植物的存在对于有效防治坡面水土流失、浅层滑坡，降低边坡土体龟裂程度，减少边坡表层土体流失，增加边坡表层土体稳定性等起着重要作用[1]。植物根系穿过土体，与土体颗粒相互接触、穿插和缠绕，与土体颗粒之间形成一种天然的根-土复合体[2]。根-土复合体的强度对坡体的稳定性起着重要作用[3-11]，是准确评价根系增强坡体稳定性的必要条件。……