孔洞尺寸效应对岩石单轴压缩力学强度及破坏特征影响试验研究  

Experimental Research on Influence of Size Effect on Compression Mechanical Strength and Failure Characteristics of Rock

作　　者：戎虎仁[1] 王海龙[1] 王占盛 冯梅梅[3] 穆柏林 王子河 

机构地区：[1]河北建筑工程学院土木工程学院,河北张家口075000 [2]中铁二院工程集团有限公司科学技术研究院,成都610000 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [4]水利部牧区水利科学研究所,呼和浩特021002

出　　处：《铁道标准设计》2017年第8期96-100,共5页Railway Standard Design

基　　金：国家自然基金青年基金(51404266);河北省教育厅科技青年基金(QN2016066);张家口市科学技术和地震局指令项目(No.1611061A);河北建筑工程学院校级基金(B-201602);中国中铁重点科研课题(2016-重点-27)

摘　　要：为了研究孔洞尺寸效应对岩石力学强度的影响,利用岩石伺服压力机对含不同孔洞直径的岩石进行单轴压缩,并通过高速摄像机记录其破坏特征及裂纹扩展过程,从裂纹扩展角度阐述强度弱化机理。研究表明:(1)随着孔洞直径的增大,其抗压强度随之而减小,但降低速率逐渐减小;(2)起裂裂纹类型控制脱落面积,进而影响岩石宏观力学强度;(3)孔洞直径为6 mm、8 mm试样起裂裂纹为反向拉伸裂纹,反向拉伸裂纹扩展很短;孔洞直径为10 mm、12 mm试样起裂裂纹为正向拉伸裂纹,最终贯穿试验边界的均为正向拉伸裂纹。In order to study the influence of hole size effects on rock strength,rocks with holes of different diameters are tested under uniaxial compression with a servo press, and their failure characteristics and crack propagation process are recorded by a high-speed camera to identify strength weakening mechanism in the light of crack propagation. The results show that（ 1） with the increase of hole diameter,rock compressive strength decreases,but the rate gradually reduces;（ 2） the type of initiative crack controls the area of fall-off,and thus affects the strength of rock;（3） initiative cracks of specimens of hole diameter 6 mm and 8 mm are reverse tensile cracks with very short crack propagation;initiative cracks of specimens of hole diametersare10 mm and12 mm are positive tensile cracks,cracks finally running through boundaries of specimens are all positive tensile cracks.

关 键 词：岩石 孔洞 尺寸效应 抗压强度 裂纹 

分 类 号：U451[建筑科学—桥梁与隧道工程]