高地应力下硬岩Ⅴ型破坏坑数值模拟研究
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摘要
为确定可准确模拟高地应力下硬脆性岩体破坏的本构模型,以Mine-by试验隧道为例,采用线弹性模型、理想弹塑性模型、m-0准则、CWFS模型等4种常用的本构模型对高地应力下硬岩脆性破坏的一种典型破坏模式——V型破坏坑进行数值模拟。结果表明,线弹性模型无法模拟硬岩的脆性破坏问题,仅可通过分析洞周围岩的二次应力场及强度系数分布特征粗略估计围岩张拉破坏范围;MOHR-COULOMB强度准则中不包含中间主应力σ2,无法考虑中间主应力对岩石强度的影响及岩体塑性屈服后的性能劣化,计算结果误差很大;可考虑围岩破坏过程中材料力学性能劣化的CWFS模型和m-0准则在模拟硬岩脆性破坏方面效果较好,数值结果与实际情形较为一致。研究结果可为类似工程开展岩爆破坏数值模拟和防治提供参考。
In order to find a constitutive model that can accurately simulate the damage of hard-brittle rock mass under high ground stress,the Mine-by test tunnel was taken as an example.Four typical constitutive models,including linear elastic model,ideal elastic-plastic model,m-0 criterion and CWFS model,were used to simulate a typical failure mode of hard brittle rock,namely the V-shaped failure pits of hard brittle rock under high ground stress.The results show that the linear elastic model cannot simulate the brittle failure problems of hard rock,and the tensile failure of surrounding rock can only be roughly estimated by analyzing the secondary stress distribution and the characteristic of strength factor after excavation.As the Mohr-Coulomb Model cannot involve the effect of the intermediate principal stressσ2 on the rock strength and cannot consider the performance degradation of the rock mass after the plastic yield,the calculation error of the model is very large.The CWFS model and the m-0 criterion have considered the fact that the performance of hard rock mass will degrade in the process of brittle failure,and the calculation results of the two models are in good agreement with the actual situation.Research results can provide reference for similar projects to simulate and prevent rockburst damage.
In order to find a constitutive model that can accurately simulate the damage of hard-brittle rock mass under high ground stress,the Mine-by test tunnel was taken as an example.Four typical constitutive models,including linear elastic model,ideal elastic-plastic model,m-0 criterion and CWFS model,were used to simulate a typical failure mode of hard brittle rock,namely the V-shaped failure pits of hard brittle rock under high ground stress.The results show that the linear elastic model cannot simulate the brittle failure problems of hard rock,and the tensile failure of surrounding rock can only be roughly estimated by analyzing the secondary stress distribution and the characteristic of strength factor after excavation.As the Mohr-Coulomb Model cannot involve the effect of the intermediate principal stressσ2 on the rock strength and cannot consider the performance degradation of the rock mass after the plastic yield,the calculation error of the model is very large.The CWFS model and the m-0 criterion have considered the fact that the performance of hard rock mass will degrade in the process of brittle failure,and the calculation results of the two models are in good agreement with the actual situation.Research results can provide reference for similar projects to simulate and prevent rockburst damage.
引文
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[4] Martini C D,Kaiser P K,Mccreath D R.Hoek-Brown Parameters for Predicting the Depth of Brittle Failure Around Tunnels[J].Canadian Geotechnical Journal,1999,36(1):136-151.
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[6]黄书岭.高应力下脆性岩石的力学模型与工程应用研究[D].武汉:中国科学院武汉岩土力学研究所,2008.
[7]姚成林.深埋长隧洞岩爆灾害机理及判据研究[D].北京:中国地质大学,2014.
[2] Hajiabdolmajid V,Kaiser P K,Martini C D.Modelling Brittle Failure of Rock[J].International Journal of Rock Mechanics and Mining Sciences,2002,39(6):731-741.
[3] Edelbro C.Numerical Modelling of Observed Fallouts in Hard Rock Masses Using an Instantaneous Cohesion-softening Friction-hardening Model[J].Tunnelling and Underground Space Technology,2009,24(4):398-409.
[4] Martini C D,Kaiser P K,Mccreath D R.Hoek-Brown Parameters for Predicting the Depth of Brittle Failure Around Tunnels[J].Canadian Geotechnical Journal,1999,36(1):136-151.
[5]江权.高地应力下硬岩弹脆塑性劣化本构模型与大型地下洞室群围岩稳定性分析[D].武汉:中国科学院武汉岩土力学研究所,2007.
[6]黄书岭.高应力下脆性岩石的力学模型与工程应用研究[D].武汉:中国科学院武汉岩土力学研究所,2008.
[7]姚成林.深埋长隧洞岩爆灾害机理及判据研究[D].北京:中国地质大学,2014.