【摘要】 花岗岩类土质边坡由于其较强的锚固能力,在高边坡加固工程实践中越来越多地采用锚索和锚杆组合锚固技术,但这种主被动组合锚固措施的设计方法尚不成熟。现有设计方法多仅考虑锚杆对边坡局部稳定性的贡献,而较少考虑其对边坡整体稳定性所起的作用,让锚索承担所有的剩余下滑力。故提出一种新的锚索/锚杆组合加固边坡的设计方法。该方法考虑锚杆对边坡整体稳定性的贡献,故提出锚索与锚杆受力的分配方法;通过降低锚索的主动锚固预应力,使边坡的变形调动锚杆的被动抗拔力,最终达到主被动锚协调作用的效果。与以往设计方法相比,所提方法可以减小锚索的设计吨位,从而减少钢铰线用量,节约工程造价;而且预应力减小可以降低钢铰线的应力腐蚀,提高锚索的长期稳定性。以国道G323一花岗岩类土质边坡为例,通过现场锚杆轴力、锚索预应力及边坡地表位移的监测,论证所提设计方法的可行性。更多还原

【Abstract】 Combined anchoring technique of tiebacks and soil nails is frequently used in practice for stability of granitoid soil slopes due to their higher anchorage capacity.Despite the routine use,the existing design method for the combination remains however controversial,in which the soil nails are designed to enhance local stability rather than contribute to overall stability of the slopes.The tiebacks are always designed to balance the driving force of a slope.Thus,the current design method cannot reflect the advantages of the combination.Attempting to solve the problem,a new design method is presented,in which the contribution of the soil nails,as well as the tiebacks,to overall stability of a slope is taken into consideration.As a result of this consideration,the preload of the tiebacks decreases and the slope consequently moves(the quantity of the movement is very small) and the movement mobilizes the resistance force of soil nails.By this process,the passive and active anchors work harmoniously;and the stress corrosion possibility of the active anchors(tiebacks) is reduced due to the decreasing of the preload resulting in a better long-term stability.Also,the amount of the tiebacks may decrease,which can save the construction cost.A granitoid soil slope along G323 national highway in China is taken for example to validate the presented design method by the field investigations of preload in some tiebacks,the stress in some soil nails and the ground surface displacement.更多还原