中南大学学报（自然科学版）2025，Vol.56Issue(4)：1564-1577,14.DOI:10.11817/j.issn.1672-7207.2025.04.026
基于离散元模拟的砂岩水力耦合特性及破裂机制研究
Study on hydraulic coupling characteristics and fracture mechanism of sandstone based on discrete element simulation
摘要
Abstract
In order to explore the evolution characteristics and fracture mechanism of seepage field under the action of rock hydraulic coupling,a CFD-DEM fluid-structure coupling model was established based on the computational fluid dynamics(CFD)module built in PFC3D,and the hydraulic coupling process of rock was simulated.Combined with laboratory tests,the evolution of micro-cracks and seepage field in the hydraulic coupling process of rock was analyzed,and the failure mode of the sample was evaluated.The results show that when the specimen is loaded,the tension and shear microcracks cross each other at the fracture position,forming a macroscopic shear band,resulting in shear failure mode.With the increase of osmotic pressure,the total number of microcracks,fabric contact force and contact number decrease and the brittle fracture of rock is more obvious after the peak stress.The evolution of seepage field in rock under the action of hydraulic coupling is closely related to the development of micro-cracks.During the whole test,the fluid in the rock sample mainly permeated along the newly formed microcracks and shear zone,while the seepage field in the undamaged zone does not change much in the shear zone,which corresponds to the sharp increase in permeability in the laboratory test.Acoustic emission ringing count divides the sample rupture process into four stages,lossless period,quiet period,growth period and explosive period.In this period,the ringing count is relatively uniform,and the cumulative ringing count increases step by step until the strength of the sample reaches the peak point.This feature can be used as a precursor criterion for rock failure.关键词
离散元/水力耦合/渗流场/细观损伤/声发射/破裂机制/各向异性Key words
discrete element/hydraulic coupling/seepage field/microscopic damage/acoustic emission/rupture mechanism/anisotropy分类
建筑与水利引用本文复制引用
宋勇军,安旭晨,孙银伟,谢丽君,卢云龙,王双龙..基于离散元模拟的砂岩水力耦合特性及破裂机制研究[J].中南大学学报（自然科学版）,2025,56(4):1564-1577,14.基金项目
国家自然科学基金资助项目(11972283,42277182)(Projects(11972283,42277182)supported by the National Natural Science Foundation of China) （11972283,42277182）
