Study on the fractal properties of soil pore structure using NMR technology
基于NMR技术的土孔隙结构分形特性研究

摘要

土孔隙结构特征是影响土渗透性的重要因素，以粉质黏土为研究对象，通过离心- NMR试验和三轴固结-NMR试验，基于分形理论对土孔隙结构的分形特性进行研究。结果表明：固结压力对土样大孔隙含量的影响显著，而对中小孔隙含量的影响甚小，固结压力对土体孔隙结构的影响主要取决于对大孔隙的改变。土样的孔隙结构呈双重分形特征，不同固结压力下，土样大孔隙、整体孔隙的分形维数均在[2,3]区间，满足分形特征且均与孔隙比 呈良好的负相关线性关系。为基于孔隙比 预测土体大孔隙、整体孔隙的结构分形特征提供了新途径。

Abstract

Soil pore structure characteristics constitute a crucial factor governing soil permeability. Using silty clay as the research object, centrifugal-NMR tests and triaxial consolidation-NMR tests were performed to investigate the fractal characteristics of soil pore structure within the framework of fractal theory. The results demonstrate that consolidation pressure exerts a significant influence on the macropore content of soil samples, whereas its effect on the content of mesopores and micropores is negligible. The impact of consolidation pressure on soil pore structure is primarily dominated by the modification of macropores. The pore structure of soil samples presents dual fractal characteristics. Under various consolidation pressures, the fractal dimensions of macropores and total pores in soil samples all lie within the interval [2, 3], satisfying fractal behavior and exhibiting a strong negative linear correlation with void ratio. This provides a novel method for predicting the fractal characteristics of macropore and total pore structures in soils based on void ratio.