强夯碎石墩与土相互作用

为了研究碎石墩复合地基的承载机理,运用有限差分软件FLAC3D将碎石墩复合地基与灌注桩基进行了对比分析,指出灌注桩基中桩土应力比明显大于碎石墩复合地基中墩土应力比,且灌注桩基中桩土相互作用的密切程度要明显小于碎石墩复合地基中的墩土相互作用,即灌注桩基中荷载大部分由桩体承担,碎石墩复合地基则表现出更强的墩土共同承担荷载的复合地基的承载模式;此外,通过研究墩体直径对复合地基沉降的影响,发现置换率一定、路堤较高时,墩径越大复合地基沉降越小,可有效减小路堤坡脚外侧的隆起量,提高路堤稳定性。

Interaction between Tamped Gravel Piers and Soil

In order to study the bearing mechanism of gravel pier composite foundation, comparative analysis between gravel pier composite foundation and pile-foundation was performed by using finite difference software FLAC3D. The result shows that (1)the pile-soil stress ratio in pile-foundation is significantly greater than that in gravel pier composite foundation, and the pile-soil interaction in pile-foundation is significantly smaller than that in gravel pier composite foundation, i.e., most of load is carried by piles in pile-foundation, but  gravel pier composite foundation shows a stronger shared bearing pattern; (2) the diameter of stone pier also impacts on settlement of composite foundation,  i.e., the greater the pier diameter the smaller the settlement when replacement rate is fixed and embankment is higher, which can effectively reduce the outside uplift of embankment slope toe and improve embankment stability.