单轴压缩条件下灰岩强度尺寸效应试验研究  

EXPERIMENTAL STUDY ON SIZE EFFECT OF LIMESTONE STRENGTH UNDER UNIAXIAL COMPRESSION

作　　者：王兆远 乔磊 伍法权[1,2] 张宇凯 周晓霞 WANG Zhaoyuan;QIAO Lei;WU Faquan;ZHANG Yukai;ZHOU Xiaoxia(Shaoxing University,Shaoxing 312000,China;Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province,Shaoxing 312000,China)

机构地区：[1]绍兴文理学院,绍兴312000 [2]浙江省岩石力学与地质灾害实验中心,绍兴312000

出　　处：《工程地质学报》2024年第6期2228-2238,共11页Journal of Engineering Geology

基　　金：国家自然科学基金项目(资助号:U2244228,41831290);浙江省基础公益研究计划项目(资助号:LHQ20D0200001)。

摘　　要：为呼应传统大型仪器小型化的实际需求,以传统尺寸效应理论为基础,以单轴压缩试验为主要手段,以同一高径比、不同直径的灰岩试件为研究对象,研究灰岩强度尺寸效应规律,探讨强度尺寸效应产生机理。研究结果如下:提出了岩石强度尺寸效应力学模型F=ae^(-((D-b)/c)^(2)),该模型能较好地表征灰岩尺寸效应规律;随试件尺寸增大,强度、模量先增大后减小,与传统尺寸规律有所不同;峰值应变随试件尺寸的增大呈减小趋势,该趋势可用幂函数表示,泊松比无明显的尺寸效应规律;试件直径越小,其力学参数离散性越大;试件破坏形态以X状共轭剪切破坏为主要破坏形式,由压剪破坏向倒V形破坏再向单斜面剪切破坏过渡为次要破坏形式;岩石材料的不均质性是强度尺寸效应的决定性因素,而端面摩擦效应只是试验方法原因。In order to respond to the actual needs of miniaturization of traditional large instruments,based on the traditional size effect theory,uniaxial compression test is taken as the main research method.Limestone specimens with the same ratio of height to diameter and different diameters are taken as research objects to study the law of strength size effect of limestone and explore the mechanism of strength size effect.The results show that a mechanical model F=a e^((-(D-b)/c)^(2)) is proposed,which can better characterize the size effects of the strength and modulus of limestone.The uniaxial compressive strength,elastic modulus,and deformation modulus of limestone first increase and then decrease with the increase of specimen size,which is different from the traditional size law.The peak strain decreases with the increase of specimen size,which can be expressed as a power function,and Poisson's ratio has no obvious size effect.The smaller the diameter of the specimen,the greater the dispersion of its mechanical parameters.The failure mode of the specimen is dominated by X-shaped conjugate shear failure,and the secondary failure mode changes from compressive shear failure to inverted V failure and then to single slope shear failure.It is considered that the non-uniformity of rock material is the decisive factor of the strength size effect,and the end friction effect is only the test method.

关 键 词：岩石力学 尺寸效应 单轴压缩 破坏形式 

分 类 号：P642.3[天文地球—工程地质学]