膨胀岩崩解特性的干湿循环效应与粒度熵表征

发布时间：2018-01-19 20:52

本文关键词： 膨胀岩干湿循环崩解粒度熵崩解比　出处：《岩土力学》2017年07期 　论文类型：期刊论文

【摘要】：膨胀岩是一种特殊软岩,在干湿循环作用下容易崩解泥化。针对延吉膨胀岩,开展干湿循环作用下膨胀岩浸水崩解试验,研究其粒径变化规律。根据干湿循环后粒径分布,引入标准基础熵表征膨胀岩崩解特性,并与崩解比进行类比分析。研究结果表明:各粒组含量在前3次干湿循环中变化较大,第3次干湿循环后逐渐趋于稳定;随着干湿循环次数的增加,粗颗粒含量逐渐减少,细颗粒含量增加,土颗粒大小经历了由均匀到不均匀,再到均匀的过程;标准基础熵与崩解比存在明显的线性负相关关系,标准基础熵随着崩解比的增大而减小,表明利用标准基础熵表征颗粒分布规律是合理可行的;随着干循环次数的增加,标准基础熵先减小,后逐渐稳定,与级配曲线及其衍生指标变化规律相同,再次验证该方法的可行性和适用性,为膨胀岩的崩解破碎分析提供一种新的量化指标;膨胀岩路堑边坡开挖以后,应及时采取防水保湿措施,防止发生崩解泥化现象。
[Abstract]:Expansive rock is a kind of special soft rock, which is easy to collapse and muddy under the action of dry and wet cycle. In view of Yanji expansive rock, water immersion disintegration test of expansive rock under dry and wet circulation is carried out. According to the particle size distribution after dry-wet cycle, the standard basic entropy was introduced to characterize the collapse characteristics of expansive rock. The results showed that the contents of the grains changed greatly in the first three dry and wet cycles, and tended to be stable after the third dry and wet cycles. With the increase of dry and wet cycles, the content of coarse particles decreases gradually, and the content of fine particles increases, and the particle size of soil goes from uniform to uneven and then to uniform. There is an obvious linear negative correlation between the standard basic entropy and the disintegration ratio, and the standard basic entropy decreases with the increase of the disintegration ratio, which indicates that it is reasonable and feasible to use the standard basic entropy to characterize the particle distribution law. With the increase of dry cycle times, the standard basic entropy decreases first and then stabilizes gradually, which is the same as the gradation curve and its derivative index, which verifies the feasibility and applicability of the method again. It provides a new quantitative index for the breakup analysis of expansive rock. After excavation of expansive rock cutting slope, waterproof and moisturizing measures should be taken in time to prevent sloughing.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金重点项目(No.41430634) 岩土力学与工程国家重点实验室自主部署项目(No.Y11002)~~
【分类号】：TU45
【正文快照】： 膨胀岩是指能与水发生物理化学反应,易风化和易软化的一类特殊软岩,失水后吸水,常常会产生不均匀膨胀,发生泥化崩解现象[1]。膨胀岩土在我国分布广泛,一直是困扰我国岩土工程建设的难题,从南京红山窑水利枢纽到南水北调中线总干渠,从百色盆地云桂铁路工程到延吉盆地吉珲铁路客

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