基于Matlab和IPP的黄土孔隙微观结构研究

发布时间：2018-05-14 17:35

本文选题：黄土 + 微观结构　；参考：《地震工程学报》2017年01期

【摘要】：黄土的孔隙结构是区别于其他土类的重要特点之一,黄土的湿陷、震陷等宏观力学表现与其孔隙结构密切相关。本文开发了利用Matlab和IPP(Image-Pro Plus)软件相结合的方法对黄土微结构图像进行处理,提出了一种基于灰度计算土的三维孔隙率方法,并对青海西宁、甘肃永登、甘肃兰州、宁夏西吉和山西芮城五处场地的原状黄土微观结构进行了定性与定量分析。结果表明:不同地区的Q3黄土微结构往往与地域、深度以及气候条件密切相关。在定性方面,六盘山附近及以东的地区降雨量较为丰富,颗粒以集粒和凝块为主;而六盘山以西的地区气候较为干旱,颗粒之间接触面较小,易形成架空孔隙。在定量方面,在空间上自西北向东南,黄土大孔隙含量增加;在深度上自上至下,黄土颗粒相互靠拢,粒间距离减小,大孔隙含量减小;随着深度的增加,地应力逐渐增大,黄土颗粒和孔隙受到挤压发生转动和变形,中孔隙和大孔隙的椭圆率变小,其中大孔隙变化显著;土体发生重塑,孔隙排列变得有序,孔隙大小以及孔隙面积在各个区域分布相对均匀,分维数和概率熵减小,玫瑰图曲线变得圆滑。
[Abstract]:The pore structure of loess is one of the important characteristics which is different from other soil types. The macroscopic mechanical performance of loess such as collapsibility and earthquake subsidence is closely related to its pore structure. In this paper, the method of combining Matlab and IPP(Image-Pro Plus software is developed to process the micro-structure image of loess, and a three-dimensional porosity method based on gray-scale calculation of soil is put forward, and it is applied to Xining, Yongdeng, Lanzhou, Gansu, Qinghai. The microstructure of loess in five sites of Xiji and Ruicheng in Ningxia was analyzed qualitatively and quantitatively. The results show that the microstructure of Q3 loess in different regions is closely related to the region, depth and climatic conditions. In the qualitative aspect, the precipitation near and east of Liupanshan is abundant, the grain is mainly agglomerate and agglomeration, while the area west of Liupanshan is dry, the interface between particles is small, and the aerial porosity is easy to form. In quantitative terms, from northwest to southeast, the porosity of loess increases in space, and from top to bottom in depth, the loess particles close to each other, the distance between grains decreases, and the macropore content decreases. With the increase of depth, the in-situ stress increases gradually. The rotation and deformation of loess particles and pores were observed, and the ellipse ratio of mesopore and macropore became smaller, in which the macropore changed significantly, and the soil was remolded, and the pore arrangement became orderly. The pore size and pore area are relatively uniform, the fractal dimension and probability entropy decrease, and the rose curve becomes smooth.
【作者单位】：中国地震局兰州地震研究所黄土地震工程重点实验室;甘肃省岩土防灾工程技术研究中心;
【基金】：国家自然科学基金项目(41472297,51478444)
【分类号】：P642.131

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