素混凝土桩和搅拌桩处理城市道路路基的原位试验

在较差地质条件、不同填筑材料情况下,用素混凝土桩和搅拌桩进行了城市道路路基处理的原位试验,分析了超孔隙水压力、桩间土分层沉降、附加有效应力、路基深层土的侧向位移等数据。结果表明:在正常荷载作用下,素混凝土桩复合地基浅层应力向桩体集中,并通过桩向深层扩散,桩顶和桩底的刺入较为明显,有单桩效应;而对于搅拌桩,大部分桩间土和桩没有相对位移,形成了一个加固整体,应力在桩顶和桩底较集中,大部分荷载传到了桩底桩间土和下卧层中。

In-situ Experiment on Urban Road Subgrade Improved by Plain Concrete Pile and Mixed-in-place Pile

Authors analyzed in-situ experiment data of subgrade improved by plain concrete and mixed-in-place pile under bad geological condition and condition of different filling construction material including excess pore pressure,layer settlement of soils between piles,additional effective stress and lateral displacement.It shows that surface layer stress of composite subgrade with plain concrete pile improved by plain concrete is focused on pile and is diffused to deep layer;there is displacement between pile and soil on the tip and bottom of pile,then,it exists the single pile effect.But concerning subgrade improved by the mixed-in-place pile,it is reinforcement unitarity,so there isn't relative displacement between pile and soil;the stress is focused on the tip and bottom of pile and load is transferred to soil under the bottom of pile and substratum.