风雪复合侵蚀路基孔隙特征的微细观试验研究

发布时间：2019-04-25 23:05

【摘要】：风雪复合侵蚀作用是自然环境中的风、融雪和温度共同作用的结果。以内蒙古那—苏省际大通道锡林郭勒盟桑根达来段的风沙土填方路段为例,考虑不设边坡防护的裸边坡为最不利情况,利用光学显微镜测试技术,并结合数字图像相关方法,通过定义土体孔隙面积比率,对土体侵蚀前后孔隙分布特征进行定量分析,分析路基填料经历冻融风蚀复合侵蚀作用后,各测试层的影响深度,以及各测试层孔隙面积比率与融雪下渗引起的冻融侵蚀和风蚀之间的关系。测试结果表明,路基坡肩处受到复合侵蚀的影响最大,复合侵蚀影响深度约为1/6倍路基模型高度。在经受3次冻融风蚀后较未侵蚀时,坡肩处的孔隙面积比率增加了50.1%,且自坡肩向坡脚处逐渐减小,在坡脚处孔隙面积比率仅增加了30.7%。相同循环次数下,风蚀对路基坡肩的结构损伤大于融雪下渗引起的冻融损伤。
[Abstract]:Wind-snow combined erosion is the result of wind, snow melting and temperature in natural environment. Taking the sand fill section of Xilingol League in Inner Mongolia as an example, considering the bare slope without slope protection as the most disadvantageous situation, the optical microscope test technique and digital image correlation method are used in this paper. By defining the pore area ratio of soil mass, the pore distribution characteristics of soil before and after erosion are quantitatively analyzed, and the influence depth of each test layer is analyzed after the subgrade filler is subjected to freeze-thaw wind erosion composite erosion. And the relationship between the pore area ratio of each layer and freeze-thaw erosion and wind erosion caused by snow-thawing infiltration. The test results show that the influence of composite erosion on the shoulder of roadbed slope is the greatest, and the influence depth of composite erosion is about 1 / 6 times the height of subgrade model. After three times of freeze-thaw wind erosion, the ratio of pore area at the shoulder of the slope increased by 50.1%, and gradually decreased from the shoulder to the foot of the slope, and the ratio of the pore area at the foot of the slope increased by only 30.7%. Under the same number of cycles, the damage caused by wind erosion on the shoulder of roadbed slope is greater than the frost-thaw damage caused by snow-thawing infiltration.
【作者单位】：内蒙古工业大学土木工程学院;
【基金】：国家自然科学基金资助项目(51168035,50868010) 新世纪优秀人才支持计划(NCET 11 1016)
【分类号】：U416.1

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