铁道科学与工程学报2024，Vol.21Issue(7)：2969-2979,11.DOI:10.19713/j.cnki.43-1423/u.T20231684
考虑循环荷载下颗粒破碎的宕渣路基渗透系数预测
Prediction of permeability coefficients for slag embankments considering particle fragmentation subjected to cyclic loading
摘要
Abstract
This investigation was aimed at revealing the intrinsic mechanism between the slag(referring specifically to the medium-strongly weathered mudstone)crushing behavior caused by cyclic loading and its permeability characteristics.The simulation of cyclic triaxial tests was conducted through PFC 6.03D.The built-in Fish language was utilized to monitor the dynamic evolution of particle gradation,crushing rate,and porosity of slag subjected to various loading cycles.A negative exponential continuous gradation equation to describe various continuous gradation of soils was proposed by analyzing the gradation characteristics of slag under different loading cycles,and its universality was discussed.Taking the gradation equation as a pivot,a seepage tortuosity Γ model that comprehensively integrated the effects of particle grouping,and pore characteristics was constructed and based on which the Stokes pore flow permeability coefficient formula was modified.This enabled the prediction of permeability coefficients of slag(medium-strongly weathered mudstone)embankments considering particle fragmentation subjected to cyclic loading.The outcomes are as follows.As the depth of the site deepens,the modified potential breakage potential B*p decreases significantly,while the modified relative breakage rate B*r is not significantly correlated with the depth,and the tendencies of B*r can be divided into three stages:rapid growth,slow growth,and convergence stage.The porosity demonstrates similar patterns.The negative exponential continuous grading equation has great applicability to four typical gradations(concave,S-shaped,linear-like,and convex).The modified tortuosity is slightly larger than that considering the single granular shape.The complex granular shape makes the flow lines more tortuous in the region,causing the overall tortuosity to increase.The permeability coefficient k decays parabolically with B*r growth,and the shallower the locus,the more pronounced the k decay.There is a critical loading cycle making it converge at each site.The investigation can provide new insights for assessing the service performance of the slag(medium-strongly weathered mudstone)embankment.关键词
循环荷载/宕渣路基/颗粒破碎/迂曲度/渗透系数Key words
cyclic loading/slag embankment/particle fragmentation/tortuosity/permeability coefficient分类
建筑与水利引用本文复制引用
张玲,陈昀灏,徐林荣,彭文哲..考虑循环荷载下颗粒破碎的宕渣路基渗透系数预测[J].铁道科学与工程学报,2024,21(7):2969-2979,11.基金项目
国家重点研发计划(SQ2022YFB2300030-06) （SQ2022YFB2300030-06）
国家自然科学基金资助项目(U2268213,52378340,52078205,42172322) （U2268213,52378340,52078205,42172322）
岩土力学与工程国家重点实验室开放基金资助项目(SKLGME022016) （SKLGME022016）
湖南省研究生科研创新一般项目(QL20230104) （QL20230104）
