基于N法的冲洪积体路基填料剪切面细观结构特性研究

代泽宇; 毛雪松; 聂孟兰; 刘龙旗

doi:10.13204/j.gyjzG20071704

基于N法的冲洪积体路基填料剪切面细观结构特性研究

doi: 10.13204/j.gyjzG20071704

1. 长安大学公路学院特殊地区公路工程教育部重点实验室, 西安 710064;
2. 山东现代学院, 济南 250002

基金项目:

国家自然科学基金项目（51878064）。

详细信息

作者简介:
代泽宇,男,1995年出生,硕士研究生。

通讯作者:
毛雪松,女,1976年出生,博士,教授,博士生导师,xuesongmao@chd.edu.cn。

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出版历程
- 收稿日期: 2020-07-17
- 网络出版日期: 2021-10-27

STUDY ON MESOSTRUCTURAL CHARACTERISTICS OF SHEAR SURFACES FOR ALLUVIAL-DILUVIAL SUBGRADE FILLERS BASED ON THE N-METHOD

1. Key Laboratory for Special Area Highway Engineering, Ministry of Education, PRC School of Highway, Chang'an University, Xi'an 710064, China;
2. Shandong Xiandai University, Jinan 250002, China

摘要

摘要: 为研究不同级配条件下冲洪积体填料的力学和结构特性，以陕西洛南冲洪积体填料为对象，基于最大密实度理论中的N法设计了五种不同路基的填料级配，并进行大型直剪试验，分析级配对抗剪强度的影响；应用高清数码相机采集不同级配的试件剪切面图像，利用图像处理软件从细观尺度对填料剪切面细观结构特征进行分析；从宏、细观相结合的角度分析了级配对其力学特性的影响。结果表明：当形状系数n为0.55时，冲洪积体填料抗剪强度最高；剪切面上填料的孔隙形态以扁圆形为主，近等轴状次之，长条状最少；块石形态则从扁圆向近等轴形发展；剪切面孔隙面积百分含量、块石破碎率和块石轮廓分维数随着n的增大先减小后增大，在n=0.55时达到极值。
- 冲洪积体 /
- 路基填料 /
- N法 /
- 细观结构 /
- 数字图像处理
Abstract: In order to study the mechanical and structural characteristics of alluvial-diluvial subgrade fillers with different gradations, the alluvial-diluvial deposits in Luonan, Shaanxi were researched. Based on the N-method in the theory of the maximum density, five different subgrade filler gradations were designed. A large-scale direct shear test was designed to analyze the effects of gradations on the shear strength. A HD digital camera was used to collect the shear plane images of specimens different with gradations. The mesostructure characteristics of the shear plane for specimens were analyzed from the mesoscale by the software of lmage-Pro Plus. The effects of gradations on mechanical properties of fillers were analyzed from the perspective of macro and meso. The results showed that the effect of pore forms in the shear planes on shear characteristics were significant, when the pore form was oblate mainly, the shear strength of fillers was the highest and the form coefficient was 0.55; then it was equiaxed and finally was bar-type. The pore forms of fillers developed from the oblate to the equiaxed, the percentage of the pore areas, fragmentation ratios and fractal dimension values of fillers decreased first and then increased with the increase of n, and finally reached the extreme value when n was 0.55.
- alluvial-diluvial deposit /
- subgrade filler /
- N-method /
- meso-structure /
- digital image processing

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