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季节冻土地区修筑铁路客运专线面临着严重的路基冻胀问题,为研究保温板(XPS)在季节冻土地区路基工程中的防冻胀效果,开展了室内模型试验研究.试验结果表明:经过2个周期的试验,保温板上下温差十分明显,保温板上下温差在负温期高于正温期,保温板下土体冻结速率随保温板厚度的增加而减小.30 cm保温板下黄土的含水率随冻融过程呈单一变化规律,其他3个试验模型土体含水率在冻结开始时先减小,冻结结束时增大,最终保持稳定的趋势.4个试验模型中的下层土体冻胀量均远大于上层土体,无保温板黄土试验模型冻胀量远大于其他3个保温板试验模型;AB料冻胀量随保温板厚度的增加而减小,AB料冻胀率远小于黄土冻胀率.因此,在季节冻土地区路基设计中宜采用保温板路基,路基填料优先采用AB料.
In order to study the frost heaving expansion effect of XPS in subgrade construction in seasonal frozen soil region, indoor model test is carried out.The results show that after 2 Cycle test, the temperature difference between the top and bottom of the insulation board is very obvious, the temperature difference between the top and bottom of the insulation board is higher than the positive temperature period in the negative temperature period, and the freezing rate of the soil body under the insulation board decreases with the increase of the insulation board thickness. The moisture content of soil in the four experimental models showed a single change rule, and the soil moisture content of the other three experimental models decreased first at the beginning of freezing and then increased at the end of freezing, and eventually remained stable. The amount of expansion of AB is much larger than that of the upper soil, and the frost heaving capacity of the loess model without insulation board is much larger than the other three models. The amount of frost heaving AB decreases with the increase of the thickness of the insulation board, Loess frost heaving rate.Therefore, in the season permafrost embankment design should be used insulation board embankment, embankment filler priority AB material.