根系排布方向对香根草固土效果影响试验研究

Experimental study on the effect of root arrangement direction on soil reinforcement of vetiver grasses

随着大众环保意识不断提高及工程环境问题日益显著,植物固土护坡技术受到了广泛重视,但根系的复杂性导致其固土效果难以量化分析。本研究测取了香根草真实生长时的根周土相对密实度,后选择了三种典型根系排布方向,并以此在不同围压下开展三轴压缩试验,探讨了不同排布方向的香根草主根对砂土的加固效果。研究结果显示,香根草根系的加入显著提高了土体的强度以及内摩擦角,而对黏聚力的影响较小,其加筋效果主要来源于根-土接触界面。此外,根系的排布方向也对其固土效果有显著影响,根系的水平排布和倾斜排布的固土效果相似,都不如竖直排布的加筋效果,该研究为理解绿化后的公路边坡浅层失稳提供了可靠参考依据。

As public awareness of environmental protection continues to grow and engineering environmental issues become increasingly prominent,the technique of vegetation for soil stabilization on slopes has gained widespread attention.However,the complexity of root systems makes it challenging to quantify their soil stabilization effects.This study measured the relative compaction of soil around the roots of vetiver grass during actual growth.It then selected three typical root system orientations and conducted triaxial compression tests under various confining pressures to explore the reinforcing effects of vetiver grass roots on sandy soil in different orientations.The results showed that the inclusion of vetiver grass roots significantly increased the strength and internal friction angle of the soil,while having a lesser impact on cohesion.The reinforcing effect primarily originated from the root-soil interface.Moreover,the orientation of the root system significantly affected its soil stabilization effectiveness.The horizontal and inclined arrangements of the root system had similar stabilization effects,both less effective than the vertical arrangement.This study provides a reliable reference for understanding the shallow instability of vegetated roadside slopes after greening.