公路路堤生态边坡植被根系加筋效应的三轴试验研究

Traxial experimental study of vegetation fibril reinforcement effect of the Ecological highway embankment slope protection

采用常规静三轴不固结不排水试验来探究边坡植被根系含量和压实度对重塑非饱和粉质粘土抗剪强度指标的影响规律.通过试验结果分析得出以下结论:(1)通过加筋土与素土对比,素土与加筋土的应力应变曲线趋势走向相近,且都呈现出硬化现象而无明显破坏峰值,说明加筋土也符合莫尔库伦强度准则.(2)加筋土的抗剪强度较素土有明显的增大,且加筋土的粘聚力随着试样中根含量比重的增加而增大,说明草根可以通过与土体相互作用约束土体的侧向变形起到加筋的效果.(3)在同一压实度条件加筋土相对素土内摩擦角变化很小,说明草根对土体的内摩擦角影响较小.(4)在含根量一定条件下,试样抗剪强度随着压实度的增大而大幅度提升,且加筋土比素土粘聚力增大幅度要大,压实度提高可以增大边坡的稳定性.(5)植被根系的加筋作用可以弥补浅层土体压实度不足,达到提高浅层边坡稳定性的效果.

Using conventional unconsolidated-undrained triaxial test to explore the shear strength pa rameters influence rule of remolded-unsaturated clay at different vegetation fibril contents and different compaction degrees. By analyzing the test results conclude that ： （1） Through the comparison for reinforced soil and pure soil, The stress-strain curves of pure soil and reinforced soil tend to be similar,and both show a hardening phenomenon without significant damage peak,indicating that the reinforced soil is also consistent with the Mohr-Coulomb strength criterion. （2）The shear strength of the reinforced soil is obviously higher than that of the pure soil, and the cohesive force of the reinforced soil increases with the increase of the proportion of the vegetation fibril content. The results show that grass roots can reinforce the lateral deformation of soil by interacting with it. （3）At the same compaction degree,the inner friction angles of reinforced soil and pure soli are close,indicating that vegetation fibril has little effect on the internal friction angle of the soil. （4） At the same vegetation fibril content,the shear strengths of reinforced soil and pure soli increase a lot with the increase of compaction degree, and the cohesion improvement of the reinforced soil goes over the pure soil, indicating that it can greatly promote the stability of the slope by increasing compaction degree. （5）The effect of vegetation fibril reinforcement can make up for the lack of compaction degree of soil, so as to improve the stability of shallow slope.