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• CN 62-1112/TF
• ISSN 1005-2518
• 创刊于1988年

十字交叉裂隙扩展机理试验与数值模拟研究

1.南华大学资源环境与安全工程学院，湖南 衡阳 421000

2.山东黄金集团有限公司深井开采实验室，山东 烟台 261442

Experimental Study and Numerical Simulation Analysis of Crack Propagation Characteristics of Crisscross Fracture

HE Guicheng,1, CHEN Kexu1,2, DAI Bing,1,2, WANG Chengcheng1

1.School of Resource Environment and Safety Engineering，University of South China，Hengyang 421000，Hunan，China

2.Deep Mining Laboratory of Shandong Gold Group Co. ，Ltd. ，Yantai 261442，Shandong，China

 基金资助: 国家自然科学基金项目“微生物胶结砂岩型地浸铀矿山隔水层的抗渗性能试验及机理研究”.  51974163湖南省教育厅重点科研基金“微波照射花岗岩型铀矿石热—力耦合作用机理及热裂断裂机制研究”.  18A248

Received: 2020-01-02   Revised: 2020-05-21   Online: 2020-08-27

Abstract

Defects in rocks make their physical properties anisotropic.When subjected to external force，the defect will crack，expand and even destroy.Therefore，it is very important to study its failure behavior to predict the instability of engineering structure.Previous studies are more concentrated on the evolution process of single fracture or non intersecting multi fracture，however，rock fracture often exists in the form of intersecting multi fracture in practical engineering.Based on RMT-150B，the cross fracture rock samples （150 mm×200 mm×45 mm） with different fracture inclination were prepared in the laboratory，and the uniaxial compression test was carried out with the displacement controlled loading mode of 0.01 mm/s.The results show that the peak strength and modulus of elasticity of the cross fracture specimen are lower than that of the intact specimen.The peak strength，modulus of elasticity and crack initiation stress increase first and then decrease with the increase of fracture inclination.In order to make up for the shortcomings of laboratory test technology in reflecting the macro and micro morphology of cross cracks，PFC2D numerical simulation technology was used to calibrate the micro parameters of the numerical model by comparing the deformation and failure characteristics of the complete specimen.The results of numerical simulation show that the relationship between peak strength，modulus of elasticity，initial crack stress and crack inclination is basically consistent with the results of laboratory tests.From the process of crack evolution，it is observed that the inclination angle of 0° is the simultaneous cracking from the tip of the primary and secondary cracks，the inclination angle of 30° is the crack initiation from the tip of the primary crack，and the inclination angle of 45° and 60° are the cracks from the tip of the secondary crack.The number curves of microcracks are divided into four stages，namely quiescent period, slow increase period, mid-term increase period, and most active period，and the growth rate of the latter stage is always higher than that of the former stage，the change characteristics of cracks are different in different stages.It can be clearly seen from the displacement field that when the inclination angles are 0°，30° and 45°respectively，the specimen is the diagonal shear failure controlled by the secondary fracture.When the inclination angle is 60°，the specimen is mainly the shear failure controlled by the main fracture.

Keywords： crisscross fracture ; rock-like specimen ; numerical simulation ; fracture propagation ; the number of microcracks ; shear failure

HE Guicheng, CHEN Kexu, DAI Bing, WANG Chengcheng. Experimental Study and Numerical Simulation Analysis of Crack Propagation Characteristics of Crisscross Fracture[J]. Gold Science and Technology, 2020, 28(4): 509-520 doi:10.11872/j.issn.1005-2518.2020.04.029

1.1 试样材料及尺寸选择

Table 1  Mechanical parameters of complete sample

图1

2a为主裂隙长度；2b为次裂隙长度；α为主裂隙与竖轴夹角

Fig.1   Model of crisscross crack specimen

图2

Fig.2   Modified RMT-150B servo rigid test machine

图3

Fig.3   Comparison of experimental and numerical simulation of failure modes of complete test block under compression

Table 2  Micro-parameters in PFC for the complete sample

图4

Fig.4   Numerical analysis model of fracture body and micro-contact diagram

图5

Fig.5   Comparison of experimental and numerical stress-strain curves under different fracture inclination angles

图6

Fig.6   Curves of peak intensity with fracture inclination angles

图7

Fig.7   Effect of fracture inclination angle on deformation parameters of crisscross fracture specimens

2.3 裂纹起裂应力分析

$K=σc1σc$

图8

Fig.8   Relationship between crack initiation stress and fracture inclination angle

3 裂纹演化分析

图9

Fig.9   Failure process diagrams of samples in PFC and experimental under different fracture inclination angles

图10

Fig.10   Curves of the number of microcracks with strain under different fracture inclination angles

4 讨论

图11

Fig.11   Main displacement，horizontal displacement and vertical displacement of the specimen after failure under different fracture inclination angles in PFC

5 结论

（1）与完整试样相比，含十字交叉裂隙试样峰值应力后跌落速度较快，且跌落速度与裂隙倾角有关。随着裂隙倾角的增加，含十字交叉裂隙试样的峰值强度呈现先增大后减小的趋势，在倾角为45°时取得最大值。

（2）含十字交叉裂隙试样中裂纹的起裂受预制裂隙倾角的影响。当裂隙倾角为0°时，微裂纹起裂于主次裂隙尖端；当裂隙倾角为30°时，微裂纹起裂于主裂隙尖端；当裂隙倾角为45°和60°时，微裂纹起裂于次裂隙尖端。试样的起裂应力随裂隙倾角的增大呈倒“V”形变化趋势。

（3）微裂纹数目曲线可划分为4个阶段，即静止期、增加缓慢期、中期增加期和最活跃期，且后一阶段增长率总是高于前一阶段。静止期微裂纹数量无变化，增加缓慢期中微裂纹形成宏观裂纹，中期增加期裂隙间距变窄，最活跃期裂纹数目增加速率呈指数上升。

（4）当裂隙倾角为0°、30°和45°时，试样的破坏模式是由次裂隙控制的对角剪切破坏；当倾角为60°时，试样的破坏模式主要是由主裂隙控制的剪切破坏。

http://www.goldsci.ac.cn/article/2020/1005-2518/1005-2518-2020-28-4-509.shtml

参考文献 原文顺序 文献年度倒序 文中引用次数倒序 被引期刊影响因子

[J].岩石力学与工程报，20123110）：1945-1956.

Qian Qihu.

Challenges faced by underground projects construction safety and countermeasures

[J].Chinese Journal of Rock Mechanics and Engineering20123110）：1945-1956.

Brace W FByerlee J D.

Recent experimental studies of brittle fracture rocks

[C]//Proeeedings of the Eighth U. S. Symposium on Rock Mechanics.MinnesotaAmerican Rock Mechanics Assonciation196757-81.

Wong L N YEinstein H H.

Systematic evaluation of cracking behavior in specimens containing single flaws under uniaxial compression

[J].International Journal of Rock Mechanics and Mining Sciences，2009462）：239-249.

[J].中南大学学报（自然科学版），2011428）：2394-2399.

Pu ChengzhiCao PingChen Yuet al.

Fracture test and failure mechanism of rock-like material of relatively different fracture apertures

[J].Journal of Central South University（Science and Technology）2011428）：2394-2399.

[J].岩土力学，201940增1）：63-7281.

Zhang GuokaiLi HaiboWang Mingyanget al.

Crack propagation characteristics in rocks containing single fissure based on acoustic testing and camera technique

[J].Rock and Soil Mechanics201940Supp.1）：63-7281.

Haeri HShahriar KMarji M Fet al.

Experimental and numerical study of crack propagation and coalescence in pre-cracked rock-like disks

[J].International Journal of Rock Mechanics and Mining Sciences，2014674）：20-28.

[J].应用基础与工程科学学报，2016246）:1232-1246.

Huang YanhuaYang Shengqi.

Particle flow analysis on crack coalescence behavior of sandstone specimen containing three pre-existing fissures under uniaxial compression

[J].Journal of Basic Science and Engineering2016246）：1232-1247.

Lee JHong J WJung J W.

The mechanism of fracture coalescence in pre-cracked rock-type material with three flaws

[J].Engineering Geology，201722331-47.

Yang S Q.

Crack coalescence behavior of brittle sandstone samples containing two coplanar fissures in the process of deformation failure

[J].Engineering Fracture Mechanics，20117817）：3059-3081.

Zhou X PCheng HFeng Y F.

An experimental study of crack coalescence behaviour in rock-like materials containing multiple flaws under uniaxial compression

[J].Rock Mechanics and Rock Engineering，2014471961-1986.

[J].岩土工程学报，2016387）：1212-1220.

Huang YanhuaYang ShengqiJu Yanget al.

Experimental study on mechanical behavior of rock-like materials containing pre-existing intermittent fissures under triaxial compression

[J].Chinese Journal of Geotechnical Mecha-nics and Engineering2016387）：1212-1220.

[J].岩石力学与工程学报，2015343）：440-451.

Yang ShengqiHuang YanhuaWen Sen.

Experimental study of mechanical behavior of red sandstone with two non-coplanar fissures after high temperature heating

[J].Chinese Journal of Rock Mechanics and Engineering2015343）：440-451.

[J].地下空间与工程学报，2018142）：461-469.

Fan XiangXie YongliLai Hongpenget al.

Numerical simulation of failure behavior of specimens with two flaws under compressive loading using PFC

[J].Chinese Journal of Underground Space and Engineering2018142）：461-469.

Huang Y HYang S QRanjith P Get al.

Strength failure behavior and crack evolution mechanism of granite containing pre-existing non-coplanar holes:Experimental stu-dy and particle flow modeling

[J].Computers and Geotechnics，201788182-198.

Sun W BDu H QShao J Let al.

Numerical Analysis of Crack Propagation Evolution of Specimens with Different Dip Angles of Cross Fractures

[J].Geotechnical and Geological Engineering，2019373379-3386.

[J].采矿与安全工程学报，2017346）：1207-1215.

Tian WenlingYang ShengqiHuang Yanhua.

PFC2D simulation on crack evolution behavior of brittle sandstone containing two coplanar fissures under different confining pressures

[J].Journal of Mining and Safety Engineering2017346）：1207-1215.

[J].中南大学学报（自然科学版），20195012）：3035-3045.

Li YongCai WeibingZhu Weishenet al.

Particle flow analysis of parallel double crack evolution under uniaxial compression

[J].Journal of Central South University（Sc-ience and Technology）20195012）：3035-3045.

Cao PingLiu TaoyingPu Chengzhiet al.

Crack propagation and coalescence of brittle rock-like specimens with pre-existing cracks in compression

[J].Engineering Geology，2015187113-121.

[J].岩石力学与工程学报，2015349）：1777-1785.

Zhang BoLi ShucaiYang Xueyinget al.

Mechanical property of rock-like material with intersecting multi-flaws under uniaxial compression

[J].Chinese Journal of Rock Mechanics and Engineering2015349）：1777-1785.

[J].岩土力学，2014357）：1863-1870.

Zhang BoLi ShucaiYang Xueyinget al.

Uniaxial compression failure mechanism of jointed rock mass with cross-cracks

[J].Rock and Soil Mechanics2014357）：1863-1870.

[J].煤炭学报，2017428）：1987-1993.

Zhang BoYang XueyingLi Shucaiet al.

Uniaxial tensile failure properties of rock-like specimens with two overlapped X-type flaws

[J].Journal of China Coal Society2017428）：1987-1993.

[J].岩石力学与工程学报，2018378）：1833-1842.

Luo KeZhao GuodongZeng Jiajunet al.

Fracture experiments and numerical simulation of cracked body in rock-like materials affected by loading rate

[J].Chinese Journal of Rock Mechanics and Engineering2018378）：1833-1842.

[J].中南大学学报（自然科学版），2012437）：2708-2715.

Pu ChengzhiCao PingYi Yongliang.

Fracture for rock-like materials with two transfixion fissures under uniaxial compression

[J].Journal of Central South University（Science and Technology）2012437）：2708 -2715.

[J].岩石力学与工程学报，2014332）：264-275.

Wang YuLi XiaoWu Yanfanget al.

Research on relationship between crack initiation stress level and brittleness indices for brittle rocks

[J].Chinese Journal of Rock Mechanics and Engineering2014332）：264-275.

Zhang X PWong L N Y.

Displacement field analysis for cracking processes in bonded-particle model

[J].Bulletin of Engineering Geology and the Environment，2014731）：13-21.

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