摘要
脆性岩石内部局部细观裂纹成核导致了岩石局部损伤,弱化了岩石局部强度,进而影响了岩石的应力-变形本构曲线形状.然而,目前关于在脆性岩石局部细观裂纹成核损伤影响下,应力-变形本构曲线的宏细观力学机理研究非常少.本文提出了一种能够解释在脆性岩石局部裂纹成核损伤突变作用下,轴向应力-应变关系、剪切应力-位移关系非光滑曲线的宏细观力学模型.该模型是基于岩石裂纹扩展与应力关系模型、岩石宏细观损伤联系、轴向力学与剪切力学行为之间关系及一种定性描述局部细观裂纹成核损伤突变随变形演化路径函数建立的.局部细观裂纹成核损伤随变形演化路径函数是通过参数ε_(1ini),Δε_(1)及ΔD,或参数D_(spini),ΔD_(sp)及ΔD进行定义.研究了以上参数对岩石轴向应力-应变关系及剪切应力-位移关系的非光滑曲线影响,着重分析了参数D_(spini),ΔD_(sp)及ΔD对岩石剪切应力-位移关系非光滑曲线的上、下剪切应力及剪切应力降的影响.在该模型基础上,结合岩石压缩声发射试验得到的岩石内部裂纹损伤随变形演化路径数据,提出了一种将理论模型应用于真实岩石力学性能分析的方法,为深部地下工程(深地工程)微震及岩爆事件预测与评价提供了重要理论支持.
The localized microcrack nucleation causes localized damage and weakens localized strength,which greatly influences the shape of the constitutive curve in the relationship between stress and deformation of brittle rocks.However,the micro-macro mechanisms of the constitutive relationship between stress and deformation influenced by the damage from the localized microcrack nucleation are rarely studied.In this study,we propose a micro-macro model influenced by the damage catastrophe from the localized microcrack nucleation to explain the unsmooth curves of axial stress-strain relation or shear stress-displacement relation.We established the model by incorporating the suggested microcrack-stress relation,micro-macro damage relation,axial and shear mechanical relation,and proposed function of microcrack nucleation-induced damage catastrophe path with deformation.We defined the damage catastrophe path in terms of the parametersε_(lini),Δε_(1),andΔD,or D_(spini),ΔD_(sp),andΔD.We discussed the effects of these parameters on the unsmooth curves of axial stress-strain relation and shear stress-displacement relation and emphatically analyzed the sensitivities of parameters—D_(spini),ΔD_(sp),andΔD—on the top shear stress,bottom shear stress,and shear stress drop in the unsmooth curve of shear stress and displacement.Inserting the experimental data of damage evolution path monitored by the acoustic emission technique into the proposed model,we further propose a method to apply the proposed model to analyze mechanics in natural rocks,which provides vital aid for prediction and evaluation of the disasters of microseismicity and rockburst in deep underground engineering.
作者
李晓照
戚承志
邵珠山
LI XiaoZhao;QI ChengZhi;SHAO ZhuShan(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Beijing Advanced Innovation Center for Future Urban Design,Beijing 100044,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi’an University of Architecture and Technology,Xi'an 710055,China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2021年第4期480-492,共13页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:51708016,51774018)
北京建筑大学金字塔人才培养工程(编号:JDYC20200307)
陕西省岩土与地下空间工程重点实验室开放基金(编号:YT201902)资助项目。
关键词
脆性岩石
局部裂纹成核
应力降
微震
岩爆
brittle rocks
localized microcrack nucleation
stress drops
microseismicity
rockbursts
