冲击作用下花岗岩的Ⅰ型裂纹形态及断面粗糙度研究  

The mode I crack morphology and section roughness of granite under impact

作　　者：王雪松 郭连军 刘鑫 邓丁 张久洋 徐振洋 WANG Xue-song;GUO Lian-jun;LIU Xin;DENG Ding;ZHANG Jiu-yang;XU Zhen-yang(School of Architecture and Civil Engineering,Shenyang University of Technology,Shenyang,Liaoning 110870,China;College of Mining Engineering,University of Science and Technology,Anshan,Liaoning 114051,China;Engineering Research Center of Green Mining of Metal Mineral Resources,Liaoning Province,Anshan,Liaoning 114051,China)

机构地区：[1]沈阳工业大学建筑与土木工程学院,辽宁沈阳110870 [2]辽宁科技大学矿业工程学院,辽宁鞍山114051 [3]辽宁省金属矿产资源绿色开采工程研究中心,辽宁鞍山114051

出　　处：《岩土力学》2023年第7期1925-1936,1948,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51974187);辽宁科技大学青年骨干人才项目(No.601011507-25);辽宁省教育厅项目(No.LJKZ0282)。

摘　　要：岩体工程中岩石常因动载作用产生断裂,研究岩石在冲击荷载下Ⅰ型裂纹的响应规律,采用分离式霍普金森压杆试验系统开展了侧开单裂纹三角形(single cleavage triangle,简称SCT)花岗岩试样的动态冲击断裂试验。采用Hough变换方法实现了表面裂纹形态长度及角度分布的定量描述,分析了表面裂纹形态与试样吸收能量的关系;并利用三维表面形貌仪获取了断面的三维点云数据,提出了基于拟合曲面阈值检测的断面重构方法,有效解决了断面三维点云数据误差点出现导致的误差问题;讨论了断面粗糙度与试件吸收能量间的关系。结果表明:随着吸收能量的增大,裂纹长度的指数分布λ值有增大的趋势;裂纹角度的分布较为平均,水平方向上的裂纹相对较少,试件能量耗散较低时,裂纹具有明显的方向性,能量耗散较高时,裂纹的弯曲程度更高且贯通性较好;断面重构方法在x、y方向点数的0.03~0.08,阈值为0.25时能够较好的完成断面处理,试件A、B断面的粗糙度统计参数随能量耗散的增大呈下降趋势。Fracture of rocks under dynamic loading is very common in rock engineering.To study the crack response of dynamic fracture of mode I cracks under impact loading,the dynamic fracture test of single cleavage triangle(SCT)granite specimens with lateral opening was carried out using a split Hopkinson pressure bar test system.The Hough transform method was used to quantitatively describe the length and angle distribution of the surface crack morphology,and the relationship between crack morphology and the energy absorbed was analyzed.The 3D point cloud data of the section was obtained by using the 3D surface topography instrument,and the section reconstruction method based on the fitting surface threshold detection was proposed,which effectively eliminates the error of the 3D point cloud data of the section.The relationship between section roughness and energy dissipation was discussed.The results show that the exponential distribution of crack lengthλtends to increase with the increase of absorbed energy;the angles of cracks are evenly distributed,with few cracks appearing in the horizontal direction;when the energy dissipation of the specimen is low,the cracks present obvious directivity,while the cracks bend more violently and the connectivity is better when the energy dissipation is high;the proposed section reconstruction method performs well at 0.03~0.08 of the points in x and y directions,and the threshold value is 0.25.The roughness statistical parameters of specimens A and B sections decrease with the increase of energy dissipation.

关 键 词：SCT试件 岩石断裂 HOUGH变换 断面粗糙度 Ⅰ型裂纹 

分 类 号：TU451[建筑科学—岩土工程]