不同裂缝扩展速率下北山花岗岩断裂特征及其演化机制研究  

Study on the fracture characteristics and evolution mechanisms of Beishan granite under different crack propagation rates

作　　者：张登科 孟涛 韩阳 王传乐 卢辉 李二兵 ZHANG Dengke;MENG Tao;HAN Yang;WANG Chuanle;LU Hui;LI Erbing(State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact,Army Engineering University of PLA,Nanjing,Jiangsu 210007,China;College of Energy Materials and Engineering,Taiyuan University of Science and Technology,Taiyuan,Shanxi 030024,China;Nanjing Urban Construction Management Group Co.,Ltd.,Nanjing,Jiangsu 210006,China;School of Transportation,Southeast University,Nanjing,Jiangsu 211189,China;College of Field Engineering,Army Engineering University of PLA,Nanjing,Jiangsu 210007,China)

机构地区：[1]中国人民解放军陆军工程大学爆炸冲击防灾减灾全国重点实验室,江苏南京210007 [2]太原科技大学能源材料与工程学院,山西太原030024 [3]南京城市建设管理集团有限公司,江苏南京210006 [4]东南大学交通学院,江苏南京211189 [5]中国人民解放军陆军工程大学野战工程学院,江苏南京210007

出　　处：《岩石力学与工程学报》2024年第11期2712-2724,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52278420);国家原子能机构核设施退役和放射性废物治理项目(科工二司[2020]194号)。

摘　　要：研究岩石在不同裂缝扩展速率下的断裂行为对分析预测工程结构的稳定性和安全性至关重要。为研究北山花岗岩在不同主裂缝扩展速率下的断裂行为,设置5种不同的加载速率以实现不同的裂缝扩展速率。试验过程中采用数字图像相关技术(DIC)与三维激光扫描技术获得试件在加载过程中的变形信息与失效后的断面形貌。基于试件应变场的变化历史,提出一种计算失效主裂缝瞬时扩展速率的新方法。结果表明,加载速率/平均裂缝扩展速率显著地影响主裂缝的扩展过程,捕捉应变场变化历史的突变点可以有效地估算失效主裂缝在不同时刻的瞬时扩展速率。在中低速加载速率范围内,主裂缝的瞬时扩展速率呈现出明显的快速增长阶段与稳定扩展阶段,而在高加载速率范围内,主裂缝的瞬时扩展速率线性增加,这一变化直接导致断裂过程区(FPZ)的萌生载荷阶段提前,断裂表面粗糙程度降低。此外,还发现失效主裂缝的平均扩展速率与断裂韧度、峰值FPZ长度呈正相关的指数函数关系,与断裂表面的分形维数呈负相关的指数函数关系。Investigating the fracture characteristics of rocks subjected to variable crack propagation rates is essential for analyzing and forecasting the stability and safety profiles of engineering infrastructures.To study the fracture behavior of Beishan granite under different main crack propagation rates,five different loading rates were set to achieve different crack propagation rates.During the test,digital image correlation(DIC)technology and three dimensional laser scanning technology were used to obtain the deformation information and fracture surface morphology of the specimen during loading.Based on the change history of the specimen strain field,a new method for calculating the instantaneous propagation rate of the failed main crack was proposed.The result show that the loading rate/average crack propagation rate significantly affected the propagation process of the main crack.Capturing the mutation point of the strain field change history can effectively estimate the instantaneous propagation rate of the failed main crack at different times.Within the range of low and medium loading rates,the instantaneous propagation rate of the main crack showed a significant rapid growth stage and stable propagation stage.However,within the range of high loading rates,the instantaneous propagation rate of the main crack increased linearly,which directly led to an earlier initiation load stage of the fracture process zone(FPZ)and a reduction in the roughness of the fracture surface.In addition,it was found that the average propagation rate of the failed main crack was positively correlated with the fracture toughness and peak FPZ length,and negatively correlated with the fractal dimension of the fracture surface.

关 键 词：岩石力学 北山花岗岩 断裂特征 裂缝扩展速率 断面粗糙度 

分 类 号：TU45[建筑科学—岩土工程]