摘要
红层软岩崩解特性随含水率的变化规律具有重要工程意义,准确地描述崩解特性需要提出合适的崩解指标。目前,广泛使用的干湿循环崩解试验无法测量崩解程度随含水率变化的连续过程,常用崩解指标(耐崩解指数Id与崩解率DR)无法准确地度量崩解程度和区分崩解特性差异。针对这问题,推导了散体材料表面积的计算方法,提出了崩解面释放率DS作用崩解指标,对比了不同崩解指标的差异;开展干湿循环浸水崩解试验,研究了循环次数对DS的影响;开展离散元法(discrete element method,DEM)模拟,研究了含水率对DS的影响。结果表明,DS存在准确物理含义,能准确描述崩解颗粒尺寸对崩解程度的影响。随着循环次数增加,在第2次干湿循环后DS变化率达到最大值,第5次崩解循环后DS趋于定值。随崩解时间t增加,DS表现出先增加后稳定的非线性变化,DS与饱和度Sr表现出线性关系。研究对于红层软岩工程应用与崩解预测具有重要意义。
The variation of the disintegration characteristics of red-layer soft rock with changes in water content has significant engineering importance.To accurately describe the disintegration characteristics,it is necessary to propose appropriate disintegration indices.Currently,widely used disintegration tests under drying-wetting cycles cannot measure the continuous process of disintegration rate as water content changes.Commonly used disintegration indices,disintegration resistance index Id and disintegration rate DR,are unable to accurately measure the degree of disintegration or distinguish differences in disintegration characteristics.To address this issue,a method for calculating the surface area of granular materials was derived.A new disintegration index,the disintegration surface release rate(DS),was proposed,and the differences between various disintegration indices were compared.Water immersion and disintegration tests were conducted to study the impact of the number of drying-wetting cycles on DS.Discrete element method(DEM)simulations were performed to study the impact of moisture content on DS.The results show that DS has an accurate physical meaning and accurately describing the influence of particle size on the disintegration rate.With the increase in the number of cycles,the DS change rate reaches its maximum after the second drying-wetting cycle,and DS tends to stabilize after the fifth disintegration cycle.As disintegration time(t)increases,DS exhibits a nonlinear change,initially increasing and then stabilizing.DS shows a linear relationship with saturation(Sr).This research is of great significance for the engineering application and disintegration prediction of red-layer soft rock.
作者
喻昭晟
陈晓斌
周雨晴
吕鑫龙
YU Zhao-sheng;CHEN Xiao-bin;ZHOU Yu-qing;LÜXin-long(School of Civil Engineering,Central South University,Changsha,Hunan 410083,China;MOE Key Laboratory of Engineering Structures of Heavy Haul Railway,Central South University,Changsha,Hunan 410083,China)
出处
《岩土力学》
北大核心
2025年第S1期285-296,共12页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51978674)
关键词
红层软岩
崩解特性
崩解指标
离散元模拟
red-layer soft rock
disintegration characteristics
disintegration indices
discrete element simulation
