胶结充填体作为人工矿柱常受到邻近矿房开采的爆破扰动,严重影响其稳定性。基于KCC(Karagozian and Case Concrete)本构模型和ALE(Arbitrary Lagrangian-Eulerian)流固耦合算法,采用LS-DYNA软件开展胶结充填体受邻近矿房爆破扰动的数值...胶结充填体作为人工矿柱常受到邻近矿房开采的爆破扰动,严重影响其稳定性。基于KCC(Karagozian and Case Concrete)本构模型和ALE(Arbitrary Lagrangian-Eulerian)流固耦合算法,采用LS-DYNA软件开展胶结充填体受邻近矿房爆破扰动的数值模拟研究,考虑不同边孔间距(0.6、1.2、1.8、2.4 m)及养护龄期(14、21、28 d)影响,揭示充填体中爆破波传播规律,探究爆破扰动对胶结充填体的动力响应及其失稳破坏情况。结果表明:邻近采场爆破对胶结充填体的破坏损伤主要集中在边界处,为提高矿石回收率并保证充填体安全,建议采用边孔间距1.2 m方案;矿山爆破开采中充填体至少需要养护21 d;低龄期充填体矿柱顶底部区域是整个矿柱中的薄弱部分,易发生失稳,应予以重点监测。展开更多
The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex ...The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex cases.The Karagozian and Case concrete(KCC)model was exploited as the material constitutive law and a new method to utilise this model for efficient and accurate simulation of quasibrittle materials is discussed.The capability of this model is evaluated by comparing the results of the numerical simulations with the corresponding experimental results,and the method itself is critically assessed.展开更多
This study aims to numerically and experimentally investigate the response of a medium strength rock material under unconfined compression loading up to failure. The unconfined compressive strength(UCS) is one of the ...This study aims to numerically and experimentally investigate the response of a medium strength rock material under unconfined compression loading up to failure. The unconfined compressive strength(UCS) is one of the most important parameters in characterising rock material behaviour. Hence the UCS is crucial in understanding the failure mechanism of fractured rocks. An effective approach to determine the UCS and to investigate the behaviours of rock materials under unconfined compression is essential in the majority of research fields of rock mechanics. The experimental configuration for the unconfined compression test, suggested by the protocols of the ASTM standard, has some limitations which affect the accuracy in determination of the real UCS. Among several alternative configurations proposed, the Mogi’s configuration seems to be the most appropriate one. Therefore, the ASTM and Mogi’s configurations were used to perform the tests on a medium strength rock material, i.e. Pietra Serena sandstone. The results using two configurations were discussed in terms of the differences. The tests were also replicated in LSDYNA using a finite element method(FEM) coupled smooth particle hydrodynamics(SPH) technique.This technique is employed in this study due to its capabilities to cope with large deformation issues related to the rocks. An advanced material model, called the Karagozian and Case Concrete(KCC) model,is implemented in the numerical simulations. The KCC model consists of three independent fixed failure surfaces and it can consider the damage accumulation based on the current state of stress among these failure surfaces. An equation-of-state(EOS) is used in conjunction with KCC material model for decoupling the volumetric and deviatoric responses. The numerical and experimental results were finally compared with the focus on the stress-strain diagram and the failure patterns. The comparison shows that the numerical results are in good agreement with the experimental results.展开更多
文摘胶结充填体作为人工矿柱常受到邻近矿房开采的爆破扰动,严重影响其稳定性。基于KCC(Karagozian and Case Concrete)本构模型和ALE(Arbitrary Lagrangian-Eulerian)流固耦合算法,采用LS-DYNA软件开展胶结充填体受邻近矿房爆破扰动的数值模拟研究,考虑不同边孔间距(0.6、1.2、1.8、2.4 m)及养护龄期(14、21、28 d)影响,揭示充填体中爆破波传播规律,探究爆破扰动对胶结充填体的动力响应及其失稳破坏情况。结果表明:邻近采场爆破对胶结充填体的破坏损伤主要集中在边界处,为提高矿石回收率并保证充填体安全,建议采用边孔间距1.2 m方案;矿山爆破开采中充填体至少需要养护21 d;低龄期充填体矿柱顶底部区域是整个矿柱中的薄弱部分,易发生失稳,应予以重点监测。
文摘The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex cases.The Karagozian and Case concrete(KCC)model was exploited as the material constitutive law and a new method to utilise this model for efficient and accurate simulation of quasibrittle materials is discussed.The capability of this model is evaluated by comparing the results of the numerical simulations with the corresponding experimental results,and the method itself is critically assessed.
文摘This study aims to numerically and experimentally investigate the response of a medium strength rock material under unconfined compression loading up to failure. The unconfined compressive strength(UCS) is one of the most important parameters in characterising rock material behaviour. Hence the UCS is crucial in understanding the failure mechanism of fractured rocks. An effective approach to determine the UCS and to investigate the behaviours of rock materials under unconfined compression is essential in the majority of research fields of rock mechanics. The experimental configuration for the unconfined compression test, suggested by the protocols of the ASTM standard, has some limitations which affect the accuracy in determination of the real UCS. Among several alternative configurations proposed, the Mogi’s configuration seems to be the most appropriate one. Therefore, the ASTM and Mogi’s configurations were used to perform the tests on a medium strength rock material, i.e. Pietra Serena sandstone. The results using two configurations were discussed in terms of the differences. The tests were also replicated in LSDYNA using a finite element method(FEM) coupled smooth particle hydrodynamics(SPH) technique.This technique is employed in this study due to its capabilities to cope with large deformation issues related to the rocks. An advanced material model, called the Karagozian and Case Concrete(KCC) model,is implemented in the numerical simulations. The KCC model consists of three independent fixed failure surfaces and it can consider the damage accumulation based on the current state of stress among these failure surfaces. An equation-of-state(EOS) is used in conjunction with KCC material model for decoupling the volumetric and deviatoric responses. The numerical and experimental results were finally compared with the focus on the stress-strain diagram and the failure patterns. The comparison shows that the numerical results are in good agreement with the experimental results.
