缩尺效应对粗粒料抗剪强度影响规律及消除方法研究  

Influence of Scale Effect on Shear Strength of Coarse Aggregate and Its Elimination Method

作　　者：蒋明杰 胡荣峰 龚健 巫志文 梅国雄[1] JIANG Mingjie;HU Rongfeng;GONG Jian;WU Zhiwen;MEI Guoxiong(School of Civil and Architectural Engineering,Guangxi University,Nanning 530004,Guangxi,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004

出　　处：《重庆交通大学学报(自然科学版)》2025年第4期45-51,共7页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家自然科学基金项目(51878185,52178321,52108309);广西自然科学基金项目(2021GXNSFBA196091)。

摘　　要：为研究缩尺效应对粗粒料抗剪强度的表现形式并探讨缩尺效应的消除方法,对砂卵砾石料和堆石料进行了大型固结排水(CD)三轴试验。首先,由于受仪器尺寸的限制,分别采用等效替换法和混合法将砂卵砾石料和堆石料进行缩尺,使其缩尺后试样颗粒最大粒径d_(M)分别达到10、20、40、60 mm。试验结果表明:d_(M)对粗粒料抗剪强度参数表观凝聚力c以及有效内摩擦角φ′有重要影响,随着d_(M)的增加,c以及φ′逐渐减少,并且c与d_(M)以及φ′与d_(M)关系曲线均可用对数函数表示。然后,根据c与d_(M)以及φ′与d_(M)关系得到了抗剪强度与d_(M)的关系式,该关系式可较为简单地预测原级配粗粒料抗剪强度。最后,推导了预测原级配粗粒料抗剪强度的估算公式,验证了该公式的可靠性,结合抗剪强度与d_(M)的关系式互相证明了2个公式均能较为准确地预测原级配粗粒料抗剪强度,从而提出缩尺效应对粗粒料抗剪强度影响的消除方法。In order to investigate the manifestation of the scale effect on the shear strength of coarse grains and to explore the method of eliminating the scale effect,large-scale consolidation and drainage(CD)triaxial tests were carried out on sand-cobble gravels and rock piles.Due to the size limitation of the apparatus,the equivalent substitution method and mixing method were used to scale the sand-cobble gravel and the piled stone respectively,so that the maximum particle size d_(M) of the scaled samples reached 10,20,40,and 60 mm,respectively.The test results show that d_(M) has a significant impact on the apparent cohesion c and effective internal friction angleφ′of the c shear strength parameters of coarse-grained materials,and c andφ′decrease gradually with the increase of d_(M).Moreover,the relationship curves between d_(M) and c as well asφ′can all be expressed as logarithmic functions.According to the relationship between d_(M) and c as well asφ′,the relation between shear strength and d_(M) is obtained,which can be used to predict the shear strength of the original graded coarse grains in a relatively simple way.On the other hand,an estimation formula for predicting the shear strength of the original graded coarse grains has been derived based on previous research results,and the reliability of this formula has been verified by experimental data.And it has been mutually proven with the relation between shear strength and d_(M) that both formulas can accurately predict the shear strength of the original grade,thus proposing a method to eliminate the influence of scale effect on shear strength.

关 键 词：岩土工程 粗粒料 抗剪强度 缩尺效应 颗粒最大粒径 表观凝聚力 有效内摩擦角 

分 类 号：TU43[建筑科学—岩土工程]