桩承式路堤土拱效应三维分析

通过模型试验和有限元分析,研究桩承式路堤中填土的破坏模式。结果表明,对于填土高度与桩净间距之比H/（s-a）≤1的低路堤,填土中的破坏面为通过桩边缘的竖直面;而对于H/（s-a）≥1.5的高路堤,破坏面为位于桩顶以上的泡状曲面,可假设为对数螺旋曲面。基于模型试验和有限元分析得到的破坏模式,建立了土拱效应的三维简化分析方法,并与有限元和文献收集得到的试验数据进行了比较。结果表明,由于采用了合适的破坏面假设,该简化方法的计算结果可靠合理。

A Three Dimensional Simplified Method for Analysis of Soil Arching Effect in the Pile-supported Embankments

To improve the understanding of the soil aching effect in the embankment fill,a series of model tests and finite element analysis were carried out.It is found that for low fill height relative to the net pile spacing,H/s-a≤1,the failure surface is vertical or slightly inclined which starts from the pile edge and goes through the whole fill height.For H/s-a≥1.5,the developed bulb shaped rupture surface is located near the pile head and can be approximated as a logarithmic spiral surface.By using the failure surface shape determined from the model test and FEM analyses,a three dimensional simplified method to evaluate the soil arching effect was proposed.The computed results were compared with FEM results and the experimental data collected from literatures,it is found that the present simplified method can predict reliable results.