强夯对黄土粒度组成及湿陷性的影响研究

Study on Effect of Dynamic Consolidation to Grain-size Composition and Collapsibility of Loess

在电镜扫描和高精度的粒度分析试验的基础上,讨论了西安至禹门口高速公路路基黄土采用强夯处理前后的粒度组成变化,并分析了这种变化及其对黄土湿陷性的影响。得出了"强夯的冲击能破坏了黄土的初始颗粒骨架,黄土中集粒、团块表面的胶结物剥落,颗粒变细,并填充到孔隙中,使得孔隙减小,土体结构变密,黄土湿陷性减弱甚至消失"的重结论。揭示了强夯处理黄土湿陷性的机理。

Based on the electron microscope scanning and the test of grain-size with high precision, the changes of grainsize composition before and after the treatment of dynamic consolidation are discussed with the subgrade loess of Xi＇an-Yumenkou express way,and its effect on loess collapsibility is also analyzed. It could be concluded that dynamic consolidation could destroy the original grain-framework of loess, the surface cementation of conglomeration peeled, grain become thinner and filled in pores which made pores significantly reduced; soil structure become compacted and loess-collapsibility become weaker or even disappear. This study reveals the mechanism of loess-collapsibility treated with dynamic consolidation.