微型桩-香根草协同护坡试验与计算研究

Experimental and Calculation Analysis of Slope Protection by Collaborated Micropiles and Vetiver

单一的香根草护坡或微型桩护坡在边坡加固与防护工程中均得到了广泛应用,但针对两者协同护坡的研究和相关工程应用相对较少。边坡安全系数作为评判边坡稳定性的重要依据之一,其计算分析结果的准确程度高,可提升滑坡灾害的预测水平,从而降低损失。通过室外大比例尺模型试验,采用坡顶分级堆载对植被与微型桩协同护坡的效果进行试验,并对采用多种理论与数值方法求得的边坡安全系数进行了比较,分析了香根草及微型桩对边坡安全系数的影响。试验与计算结果表明:采用三维有限元分析得到的安全系数略高于二维有限元分析;相比于素土边坡,微型桩-香根草协同护坡能极大地提高边坡安全系数,有效提高坡体稳定性,而且能够提高边坡承受荷载能力,研究结果可为生态防护与工程加固措施协同护坡工程设计提供理论依据。

Slope protection using either vetiver or micropiles is widely used in reinforcement and protection of slopes;however,they are seldom researched in engineering applications for slope protection.The slope safety factor can be used as a basis for assessing slope stability,and accurate calculation and analysis can prevent landslides and other geological disasters from occurring,reducing property loss.Under the same site conditions,vetiver was compared with common grass after 6 months of free growth,and its root system was significantly better than that of ordinary grass.The test slope soil parameters were measured using a micro-earth pressure box and static resistor strain gauge.Through a large-scale test model,the effect of vetiver and micropile slope protection was tested using the method of slope top graded stowage loading.The experimental results show that the stability safety coefficient of the vetiver and micropile slopes increase to 7.82%and 21.77%,respectively,compared with the plain soil slope.This indicates that the slope of the fennel grass can improve the slope stability by a small margin.Furthermore,the influence of vetiver and micropiles on the slope safety factor was analyzed by using traditional geotechnical software to calculate the slope safety factor,and the results were compared using ABAQUS software finite element calculations.The calculation formula for the two-and three-dimensional slope safety coefficients of a homogeneous slope was achieved by the strength reduction method,and the results show that the safety factor obtained using three-dimensional finite element analysis is slightly higher than that calculated by two-dimensional finite element analysis.Combined vetiver and micropile slope protection significantly improves the slope safety factor and slope integrity stability,and can improve the slope bearing load capacity.This provides a theoretical basis for slope ecology and collaborative engineering protection design.