含弧形裂隙岩体的裂纹扩展模拟研究
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摘要
为研究弧形裂隙对裂隙岩体的力学性能和裂纹扩展的影响,选取FLAC~(3D)软件中应变软化模型和空模型来模拟岩石裂隙扩展情况,将塑性区视为反应裂隙扩展的依据,研究单轴压缩荷载下裂隙拱高、裂隙弦长及裂隙倾角等对弧形裂隙扩展规律及力学特性的影响。模拟结果表明试件峰值强度随着拱高的增加而降低,且裂隙弦长对峰值强度也有影响。裂隙倾角影响着弧形裂隙的扩展路径,当倾角变大时,试件峰值强度也随之增加。最后采用模型试验对模拟结果进行初步验证。
To investigate the effect of arc cracks on mechanical properties and crack propagation of fractured rock mass, the strain softening model and the null model in FLAC~(3D) software are adopted respectively to describe the mechanical behavior of the rock and crack, and the plastic zone is regarded as the basis for crack propagation. This numerical calculation model is adopted to study the effect of arch height, chord length and inclination on the crack propagation path and rock mass mechanical behavior under uniaxial compression. The calculation results are as follows: the peak strength of the sample decreases as the arch height increases, and the chord length also affects the peak strength. The crack inclination has an effect on the expansion path of arc cracks. The peak strength of the sample increases when the inclination becomes larger. Finally, the model test is used to verify the rationality of the simulation results.
To investigate the effect of arc cracks on mechanical properties and crack propagation of fractured rock mass, the strain softening model and the null model in FLAC~(3D) software are adopted respectively to describe the mechanical behavior of the rock and crack, and the plastic zone is regarded as the basis for crack propagation. This numerical calculation model is adopted to study the effect of arch height, chord length and inclination on the crack propagation path and rock mass mechanical behavior under uniaxial compression. The calculation results are as follows: the peak strength of the sample decreases as the arch height increases, and the chord length also affects the peak strength. The crack inclination has an effect on the expansion path of arc cracks. The peak strength of the sample increases when the inclination becomes larger. Finally, the model test is used to verify the rationality of the simulation results.
引文
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[12]李胡勇,马铮铮,张亚东,等.基于应变软化模型的岩体单轴压缩裂隙扩展[J].煤炭安全,2018,49(4):217-220.
[13]熊飞,靖洪文,苏海健,等.尖端相交裂隙砂岩强度与破裂演化特征试验研究[J].煤炭学报,2017,42(4):886-895.
[2]Prudencio M,Van Sint Jan M.Strength and failure modes of rock mass models with non-persistent joints[J].International Journal of Rock Mechanics and Mining Sciences,2007,44(6):890-902.
[3]Park C H,Bobet A.Crack coalescence in specimens with open and closed flaws:A comparison[J].International Journal of Rock Mechanics&Mining Sciences,2009,46:819-829.
[4]YANG S Q,JING H W.Strength failure and crack coalescence behavior of brittle sandstone samplescontaining a single fissure under uniaxial compression[J].International Journal of Fracture,2011,168(2):227-250.
[5]YANG S Q,YANG D S,JING H W,et al.An experimental study of the fracture coalescence behaviorof brittle sandstone specimens containing three fissures[J].Rock Mechanics and Rock Engineering,2012,45(4):563-582.
[6]Ramamurthy T.Shear strength response of some geological materials in triaxial compression[J].International Journal of Rock Mechanics&Mining Sciences,2001,38:683-697.
[7]Yang Y T,Zheng H.A three-node triangular element fitted to numerical manifoldmethod with continuous nodal stress for crack analysis[J].Engineering Fracture Mechanics,2016,162:51-75.
[8]Bahaaddini M,Sharrock G,Hebblewhite BK.Numerical investigation of the effect of joint geometrical parameters on the mechanical properties of a non-persistent jointed rock mass under uniaxial compression[J].Computers and Geotechnics,2013,49:206-225.
[9]李广林,郤保平,崔继明.不同地应力下水压裂隙扩展演化数值模拟分析[J].矿业研究与开发,2017,37(10):86-88.
[10]Tang C A,Kou S Q.Crack propagation and coalescence in brittle materials under compression[J].Engineering Fracture Mechanics,1998,61:311-324.
[11]付金伟,朱维申,王向刚,等.节理岩体裂隙扩展过程一种新改进的弹脆性模拟方法及应用[J].岩石力学与工程学报,2012,31(10):2088-2095.
[12]李胡勇,马铮铮,张亚东,等.基于应变软化模型的岩体单轴压缩裂隙扩展[J].煤炭安全,2018,49(4):217-220.
[13]熊飞,靖洪文,苏海健,等.尖端相交裂隙砂岩强度与破裂演化特征试验研究[J].煤炭学报,2017,42(4):886-895.