多年冻土区片块石路基尺度效应的数值研究

Numerical Study on the Scale Effect of Crushed-rock Embankment in Permafrost Regions

为了分析片块石路基的尺度效应问题,通过数值手段,计算相同条件下窄幅和宽幅路基的片块石层对流强度和冻土地温。研究结果表明:相比于窄幅路基,宽幅片块石路基的最大对流风速降低了34 %,冻土上限下降了1.08 m,冻土年平均地温升高了0.90 ℃。因此,对片块石路基的尺度效应问题不容忽视,表现在工程应用上,不能简单地将片块石路基直接应用于多年冻土区高速公路宽幅路基,应采取结构优化设计,或与其他结构组成复合路基结构。

In order to analyze the scale effect of crushed-rock embankment, the convection strength and ground temperature of narrow and wide crushed-rock embankments was calculated through numerical method in this paper. The results showed that, compared with narrow embankment, the maximum convective wind speed of wide embankment was decreased by 34 %, the permafrost upper limit moved downwards by 1.08 m, and the mean annual ground temperature was increased by 0.90 ℃. The study in this paper illustrated that, the scale effect of crushed-rock embankment is nonnegligible. As for engineering application, the crushed-rock embankment can't be directly applied to wide expressway embankment, which should be conducted a structural optimization or composed compound subgrade structure with other structures.