橡胶颗粒改良粉煤灰土的土水特征曲线研究

Study on the Soil-Water Characteristic Curve of Fly Ash Soil Modified by Crumb Rubber

摘要: 随着我国公路建设的快速发展和公路等级的提高，涌现出越来越多的非饱和土的工程问题，研究基质吸力可以对非饱和土的抗剪强度、渗透系数、持水系数等做出预测，具有重要的工程实践意义。季冻区路基冻害对道路的使用性能造成了较大的影响，在我国路基冻害防治的研究也在一直进行，路基土在冻融循环作用下的研究也具有重要意义。本文通过滤纸法测定了橡胶颗粒改良粉煤灰土与粉质黏土的基质吸力，用Fredlund模型对两种土进行了土水特征曲线的拟合，并进一步测定了冻融循环下两种土的基质吸力，分析了冻融循环次数与基质吸力之间的关系。试验结果表明：两种土的基质吸力均随着干密度的减小而减小。冻融循环作用下，橡胶颗粒改良粉煤灰土的稳定性好于粉质黏土。

Abstract: With the rapid development of China’s highway construction and the improvement of highway grade, more and more engineering problems of unsaturated soils have emerged. Studying the matrix suction can predict the shear strength, permeability coefficient and moisture holding capacity of unsaturated soil, which is of great significance for engineering practice. In particular, the frost damage of the subgrade soil will cause great harm to the performance of highways, so the study of the subgrade soil under freeze-thaw cycles in seasonally frozen area is also important and the re-search on the prevention and control of frost damage has been carried out in our country. In this paper, the matrix suction of the modified soil and silty clay is measured by filter paper method and Fredlund model is used to simulate the soil-water characteristic curve. Furthermore, the matrix suction of the two soils under freeze-thaw cycles is measured and the relationship between the number of freeze-thaw cycles and the matrix suction is analyzed. The results show that the matrix suction of the two soils decreases as the dry density decreases. The stability of fly ash soil modified by crumb rubber is much better than that of silty clay under freeze-thaw cycles.