水利水电技术（中英文）2024，Vol.55Issue(2)：180-192,13.DOI:10.13928/j.cnki.wrahe.2024.02.016
卸荷条件下花岗岩破裂面粗糙度特征及成因分析试验研究
Experimental study on roughness characteristics and genesis analysis of granitefracture surface under unloading condition
摘要
Abstract
[Objective]In order to explore the changes and causes of fracture morphology of engineering rock mass during loading and unloading under high stress.[Methods]The roughness is used as an important parameter to describe the geometric character-istics of the morphology,and the morphology change is quantitatively characterized.The tensile-shear ratio is used as an impor-tant parameter to describe the fracture characteristics,and the fracture mode changes are quantitatively characterized.This paper selects two types of granite to carry out loading and unloading mechanical tests,and analyzes the roughness and causes of the fracture surface by digital image technology.[Results]According to the result,Under the condition of high stress unloading,ini-tial confining pressure,unloading confining pressure rate and mineral particle size have a negative correlation effect on the rough-ness of granite fracture surface.The result of microscopic observation of ultra-depth of field show that the lower the roughness of granite,the higher the proportion of shear fracture in the fracture.In the process of confining pressure unloading failure,30 MPa confining pressure unloading,rock fracture surface is mainly intergranular tensile fracture,40 MPa confining pressure unloading,mainly intergranular and transgranular tensile shear composite fracture,50 MPa confining pressure unloading,mainly transgranu-lar shear fracture.With the increase of mineral particle size and unloading confining pressure rate,the proportion of shear fracture increases.Under high confining pressure unloading,the higher the proportion of tensile fracture is,the rougher the frac-ture surface is.[Conclusion]On the contrary,the higher the proportion of shear is,the lower the roughness of the fracture surface is.关键词
花岗岩/卸荷试验/粗糙程度/断裂形貌/拉剪比/力学性能/影响因素Key words
granite/unloading test/roughness/fracture morphology/tension shear ratio/mechanical properties/influence factor分类
建筑与水利引用本文复制引用
胡宝文,南博文,吕聪瑞,宿辉,宋金科,李江哲,李世奇..卸荷条件下花岗岩破裂面粗糙度特征及成因分析试验研究[J].水利水电技术（中英文）,2024,55(2):180-192,13.基金项目
河北省自然科学基金项目基础研究专项(E2020402087) （E2020402087）
河北省自然科学基金资助项目(E2019402256) （E2019402256）
国家重点研发计划"超大型深井矿山高效绿色开采技术与智能装备"(2022YFC2904100) （2022YFC2904100）
佛山市科技创新专项资金项目(BK22BE024) （BK22BE024）
