干燥过程中花岗岩风化土开裂与收缩特征的试验研究  

Experimental study on cracking and shrinkage characteristics of granite weathered soil during drying process

作　　者：安然 蔡苏童 汪亦显[1] 姚传芹 AN Ran;CAI Sutong;WANG Yixian;YAO Chuanqin(School of Civil and Hydraulic Engineering,Hefei University of Technology,Hefei 230009,China;College of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;Architecture and Engineering College,Shanghai Normal University,Shanghai 201418,China)

机构地区：[1]合肥工业大学土木与水利工程学院,安徽合肥230009 [2]武汉科技大学城市建设学院,湖北武汉430065 [3]上海师范大学建筑工程学院,上海201418

出　　处：《岩土工程学报》2025年第3期652-658,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(12102312);陕西省重点研发计划项目(2024GH-YBXM-05)。

摘　　要：为了揭示干燥气候条件下花岗岩风化土的开裂与收缩特性的演化机制,开展不同脱湿时间的微米计算机层析识别(μ-CT)扫描与收缩试验,获得了花岗岩风化土三维孔隙分布与收缩曲线,并讨论了裂隙演化规律与收缩特征的关联性。结果表明:根据μ-CT扫描的三维重建模型,花岗岩风化土内部组分分为黏土、石英颗粒、铁质胶结物和孔隙;总孔隙率和连通裂隙度随脱湿时间增加显著提高;在干燥脱湿作用下,不同等效孔径Re的孔隙均有一定程度的增加,等效孔径大于100μm的裂隙数量增幅最明显;花岗岩风化土的收缩曲线分为正常收缩、残余收缩和零收缩阶段;表面裂隙率Rsc在一定程度上可以预测土体收缩特征,但由μ-CT扫描获得的三维裂隙与土体真实收缩变形具有更好的相关性。To reveal the evolution mechanism of its cracking and shrinkage characteristics under dry climate conditions,the 3D pore distribution and shrinkage curves of granite weathered soil are obtained by the micron computer chromatography identification(μ-CT)scanning and shrinkage tests at different dehumidification time.Furthermore,the relationship between the rules of crack evolution and the characteristics of shrinkage is discussed.The test results show that the internal components of granite weathered soil can be divided into clay,quartz particles,iron cements and pores according to the 3D reconstruction model from theμ-CT scanning.The total porosity and content of connected cracks increase significantly with the elapse of dehumidification time.Under the drying effects,the pores with different equivalent aperture(Re)increase to a certain extent,and the number of cracks with the equivalent aperture larger than 100μm increases most obviously.The shrinkage curve of granite weathered soil can be divided into normal shrinkage,residual shrinkage and zero shrinkage stages.Besides,the ratio of surface cracks(Rsc)can be used to predict the shrinkage characteristics of soils,but the index of three-dimensional cracks obtained by theμ-CT scanning have better correlation with the real shrinkage of soils.

关 键 词：花岗岩风化土 干燥脱湿 μ-CT扫描 三维孔隙分布 收缩变形 

分 类 号：TU442[建筑科学—岩土工程]