基于DFN-DEM的矿区裂隙岩体尺寸效应及卸荷力学特性模拟研究

金属矿山 ›› 2025, Vol. 54 ›› Issue (12): 37-47.

基于DFN-DEM的矿区裂隙岩体尺寸效应及卸荷力学特性模拟研究

冯兴隆1　罗新飏2　李　亮1　刘新荣2　龙肖霞1　眭素刚3,4

1.云南迪庆有色金属有限责任公司,云南迪庆 674400;2.重庆大学土木工程学院,重庆 400045;3.云南省岩土工程与地质灾害重点实验室,云南昆明 650224;4.中国有色金属工业昆明勘察设计研究院有限公司,云南昆明 650224

出版日期:2025-12-15 发布日期:2025-12-30
通讯作者: 罗新飏(1997—),男,博士研究生。
作者简介:冯兴隆(1980—),男,正高级工程师。
基金资助:
云南省科学技术厅基础研究专项(编号:202301AS070008);云南省科学技术厅科技人才与平台计划项目(编号:202205AD160063);云南迪庆有色金属有限责任公司科研项目(编号:DQYS-ZYB-09-(2021)001)。

Simulation Study on Size Effect and Unloading Mechanical Properties of Fractured Rock Mass in Mining Area Based on DFN-DEM

FENG Xinglong¹　LUO Xinyang²　LI Liang¹　LIU Xinrong²　LONG Xiaoxia¹　SUI Sugang^3,4#br#

1.Yunnan Diqing Nonferrous Metals Limited Liability Company,Diqing 674400,China; 2.College of Civil Engineering,Chongqing University,Chongqing 400045,China; 3.Yunnan Key Laboratory of Geotechnical Engineering and Geohazards,Kunming 650224,China; 4.Kunming Prospecting Design Institute of China Nonferrous Metal Industry Co.,Ltd.,Kunming 650224,China

Online:2025-12-15 Published:2025-12-30

摘要/Abstract

摘要： 矿区边坡岩体因裂隙分布复杂、尺度效应显著及卸荷响应机制多变,面临力学参数难以等效表征、破坏机制难以准确描述等问题。采用离散元软件PFC建立DFN-DEM耦合计算模型,分析了DFN分布下试样尺寸对裂隙岩体的应力—应变曲线、破坏过程与模式和表征单元体(REV)尺寸及力学参数值的影响,并探究了REV尺寸下试样的卸荷破坏过程。研究结果表明:随着试样尺寸增大,裂隙数量增加了结构的非均质性,其破坏特征由塑性主导的延性破坏逐渐过渡为弹性主导的脆性破坏;随着试样尺寸增大,裂隙岩体的破坏模式由集中脆性破坏逐渐演化为多区协同的渐进式破坏;单轴抗压强度随尺寸增大呈负指数衰减,弹性模量则先波动后趋于稳定。在此DFN分布下裂隙岩体的REV尺寸为11 m×22 m,REV单轴抗压强度为9.21 MPa,弹性模量为27.9 GPa;卸荷过程经历加载、应力维持、逐步破坏和最终破裂4个阶段,且围压越大,卸荷后结构越不稳定,裂纹扩展和力链瓦解越迅速。研究成果可为矿区离散裂隙边坡力学参数取值与稳定性分析提供一定的帮助。

关键词: 离散裂隙网络　裂隙岩体　尺寸效应　离散元　卸荷力学特性

Abstract: Due to the complex fracture distribution,significant scale effect and variable unloading response mechanism, the slope rock mass in the mining area is faced with the problems that the mechanical parameters are difficult to be equivalently characterized and the failure mechanism is difficult to be accurately described.The discrete element software PFC was used to establish the DFN-DEM coupling calculation model.The influence of sample size on the stress-strain curve,failure process and mode of fractured rock mass and representative elementary volume(REV) size and mechanical parameter values under DFN distribution was analyzed.The unloading failure process of the sample under REV size was explored.The results show that with the increase of sample size,the number of cracks increases the heterogeneity of the structure,and the failure characteristics gradually change from ductile failure dominated by plasticity to brittle failure dominated by elasticity.With the increase of sam ple size,the failure mode of fractured rock mass gradually evolved from concentrated brittle failure to multi-zone synergistic progressive failure.The uniaxial compressive strength decreases exponentially with the increase of size,while the elastic modu lus fluctuates first and then tends to be stable.Under this DFN distribution,the REV size of fractured rock mass is 11 m×22 m,the uniaxial compressive strength of REV is 9.21 MPa,and the elastic modulus is 27.9 GPa.The unloading process under goes four stages:loading,stress maintenance,progressive failure and final fracture.The larger the confining pressure is,the more unstable the structure is after unloading,and the faster the crack propagation and force chain collapse are.The research results can provide some help for the mechanical parameter value and stability analysis of discrete fracture slope in mining area.

Key words: discrete fracture network(DFN),fractured rock mass,size effect,discrete element method(DEM),unloading mechanical property

中图分类号:

TD315

冯兴隆　罗新飏　李　亮　刘新荣　龙肖霞　眭素刚, . 基于DFN-DEM的矿区裂隙岩体尺寸效应及卸荷力学特性模拟研究[J]. 金属矿山, 2025, 54(12): 37-47.

FENG Xinglong　LUO Xinyang　LI Liang　LIU Xinrong　LONG Xiaoxia　SUI Sugang, . Simulation Study on Size Effect and Unloading Mechanical Properties of Fractured Rock Mass in Mining Area Based on DFN-DEM[J]. Metal Mine, 2025, 54(12): 37-47.

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