【作者】 黄书岭；

【导师】 冯夏庭；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2008， 博士

【摘要】 复杂应力状态下岩石的强度特征及其破坏行为一直以来是土木水利工程及相关领域中非常重要且异常复杂的研究课题之一。随着岩石工程不断向深部发展,其所处的地质和应力环境变得更为复杂,高地应力下的岩石力学问题的研究已经提上日程,特别是建立高应力下岩石的强度准则和本构模型,描述其强度特点和变形破坏规律已成为地下岩石工程的关键问题之一。鉴于此,为满足工程建设需求以及学科理论发展需要,本文通过对深部脆性岩石进行多角度力学和流变试验研究,运用岩石强度理论、弹塑性力学、流变力学和渗流力学等理论系统地研究并提出了适用于高应力下的强度准则及其本构模型,并将这一研究成果结合智能反演理论,应用于重大水利水电岩石工程建设中,来解决工程建设中遇到的实际工程问题。故,本文的研究工作主要集中在如下几个方面:1.基于锦屏深埋段大理岩单轴、三轴压缩试验、损伤控制加卸载试验、真三轴试验以及声发射试验等多角度试验的结果,从变形、强度、能量和破坏等不同角度对不同环境下脆性岩石在不同应力状态下的变形和强度特征以及能量耗散特征进行了较为系统的分析,获得了脆性岩石瞬时的基本力学特性和变形破坏规律。然后采用裂纹应变理论,明确了深部脆性岩石内部裂纹发展演化的规律以及强度破坏机理。2.基于两种强度和破坏控制机制转化的物理基础,利用Griffith理论和Weibols的有效应变能原理,提出了广义多轴应变能强度准则(GPSE),多组脆性岩石多轴试验结果证明了该强度准则的合理性以及适用性。基于该准则,分别推导了Mohr参数和Hoek参数表示的GPSE准则,为工程应用奠定了基础。3.在Mohr参数表示的GPSE准则的基础上,依据室内试验结果,分别提出了强度参数和扩容参数损伤演化公式,建立了适用于高应力下脆性岩石考虑扩容效应的硬化-软化本构模型(GPSEdshs),详细推导了该本构模型的有限差分格式,并实现了数值计算功能。基于GPSE准则,从理论和试验的角度,推导了地下岩石工程围岩体考虑扩容效应的安全评价指标即扩容安全度指标,给出了基于扩容安全度指标的围岩体开挖扰动的扩容安全分区。4.通过室内脆性岩石常规压缩试验的模拟、加拿大Mineby试验洞破坏区的模拟、考虑扩容软化本构与不考虑扩容软化本构计算结果对比以及锦屏II级水电站辅助洞横通道松动圈的模拟分析,均表明了GPSEdshs本构模型和扩容安全度指标可以较好地模拟高地应力条件下地下岩石工程脆性围岩体开挖后变形破损特征以及围岩体扩容损伤的空间分区特点。另外,算例分析表明,Mohr-Coulomb模型比GPSEdshs模型偏于保守。5.采用全自动岩石三轴蠕变伺服仪,进行了水压和应力耦合作用下锦屏深部大理岩的三轴蠕变试验,从轴向、侧向和体积变形等三个方面分析了不同围压、不同应力水平以及有无水压作用下脆性岩石的变形时效特征和演化规律,讨论了脆性岩石的等时曲线特征、变形速率特征、蠕变对变形、强度以及破坏的影响,初步掌握了复杂环境下锦屏大理岩流变特性的基本规律,明确了脆性岩石的时效破裂机理。6.在脆性岩石的流变试验认识以及前人研究的基础上,提出了考虑应力状态影响的脆性岩石非定常黏弹塑流变模型(NRM),推导了相应的蠕变方程和松弛方程,从理论上讨论了该模型的蠕变特性和松弛特性。在此基础上,结合渗流理论,提出了HM作用下脆性岩石的非定常黏弹塑流变本构计算模型,推导了它的有限差分格式,并在Flac3D中实现了数值计算功能,而数值试验表明了所研制的流变数值计算程序的合理性和正确性。然后对所提出的非定常黏弹塑流变模型进行辨识,识别出了水压和应力耦合作用下大理岩的蠕变试验参数。7.最后,将脆性岩石的力学试验以及提出的模型和安全性评价方法结合智能反演理论应用于锦屏II级引水隧洞辅助洞深埋段围岩体的稳定性研究中,采用二维和三维相结合的数值计算模型,系统地对位移矢量场、主应力矢量场、主应力路径、塑性屈服区以及扩容损伤区分布及其深度和大小等等广角度信息进行综合分析,总结了围岩体力学响应的时空演化规律和特征,并对比了有无水压时围岩体开挖引起的力学响应特征和规律,合理解释了深埋高应力下硬脆性围岩体的变形破坏滞后等问题。这些问题的研究为下一步引水隧洞的顺利施工提供了基础信息和理论依据。更多还原

【Abstract】 Strength characteristics of rock under the complex stress conditions and its fail behaviors have been one of the most important and very complex research topic in the area of civil and related projects for a long time ago. As the deep development has been into a trend in the rock projects around the world, where the geological and stress environment has become more complex, the study of rock mechanics under the condition of high stress in deep engineering has been put on the agenda, in particular, the establishment of rock strength criteria and its constitutive model, which has been one of th key issuses describing its strength characteristics and its rules of deformation and damage in underground rock engineering.In view of this, in order to meet the construction needs and the development demand of rock mechanics subject, based on the deep brittle rock multi-point mechanical and rheological experimental investigation, the strength criteria and its constitutive model which is applicable to the conditons of high stress have been systematically investigated and proposed using mechanical theory such as rock strength theory, elastoplastic mechanics, rheological mechanics and seepage mechanics. In the end, with intelligent inversion theory, the above investigation results are applied to the practice of great hydropower rock project, wich solves the practical problems encountered in the construction of the actual engineering. In sum, the main investigation works and results are listed as follows:1. Based on the multi-angle expertimental results of Jinping marble from the deep site, such as single and triaxial test, damage-control loading-unloading test, true triaxial test and acoustic emission test, a more systematic analysis on the deformation and strength characteristics,energy dissipation characteristics of the brittle rocks under different circumstances in different states of stress is carried out from the deformation, strength, energy and failure view,which has access to the brittle rock characteristics and the instantaneous basic mechanics of deformation and damage. And then using crack strain theory, the internal crack evolution and failure mechanism of the deep brittle rock are made in a detailed analysis.2. Based on the physical basis of two failure-control mechanism, a Generalized Polyaxial Strain Energy Strength Criterion(GPSE) is created using Griffith theory and Weibols’s principle of effective strain energy. The GPSE strength criterrion for rock is verified by polyaxial test data of brittle rocks that have been published. And then the GPSE criteria expressed by Mohr’s and Hoek’s parameters respectively are derived on the basis of the criteria,which laid the foundation for application of actual projects.3. On the basis of GPSE criteria expressed by Mohr’s parameters and laboratory test results, the damage evolution formulas on strength parameters and expansion parameters are proposed, and the strain hardening-softening constitutive model considered dilate effect (GPSEdshs )which is applied to the brittle rock under high stress condition is established. Then the finite difference format of the constitutive model is derivated in detail, and its numerical computing capabilities are achieved. Based on GPSE criteria, a safety evaluation named by dilate safty factor of wall rock of underground rock project is derived to make the security disturbance district of wall rock excavation from the perspective of theoretical and experimental.4. The results including fitting of triaxial compression test stress-strain curves of marble,simulation of EDZ of Canada Mineby test tunnel,comparison of analog results both dilate strain-softening constitutive and non-dilate constitutive,simulation of EDZ of testing tunnel in JinPing II diversion tunnel and so on prove that the model and the dilate safty factor are suitable for numerical calculation of underground brittle wall rockmass and suitable for space district characteristics of dilate damage of wall rockmass under high geo-stress condition. In addition, the analysis result shows that the Mohr-Coulomb model is conservative than the GPSEdshs model.5. In order to know about the rheological properties of marble of the deep site in Jinping II diversion tunnel, triaxial compression rheological experiments with water pressure coupled stress were carried out on the rock servo-controlling rheology testing machine. The aging deformation characteristics and evolution rule of the brittle rock under different confining pressure, stress level and whether water pressure or not are investigated from the axial deformation,lateral deformation and volumetric deformation, and the characteristics such as tautochrone,deformation rate, creep deformation,creep strength,creep failure and so on are discussed in detail which make us preliminary master the basic law of rheological behavior on Jinping marble under the complex environment,and illustrate aging failure mechanics of the brittle rocks.6. On the basis of previous studies and rheological experiments of brittle rock, non-stationary visco-elastop-plastic rheological model considering the effect of stress state is put forward.And then the corresponding creep equation and the relaxation equation are deduced, and the model of the creep and relaxation properties of the model are theoretically discussed. On this basis and the combination of seepage theory, the numeratical model of non-stationary visco-elastop-plastic rheological constitutive under the role of H-M is proposed, and its finite difference format is derived which is to achieve the numerical calculations in Flac3D. The numerical results show that the numerical procedure of rheological model is reasonable and correct. And then by the identification of the non-stationary visco-elastop-plastic rheological model, the creep test parameters of Jinping II marble under the water pressure coupled stress are successfully identified.7. Finally, with intelligent inversion theory, experimental and theoretical investigation results on mechanical properties of brittle rock are applied to .the study of wall rock stability in deep site of assisted tunnel of Jinping II diversion tunnel. Using numerical models of 2D and 3D, space-time evolutionary process and law of mechanical response of wall rockmass are systematically analysed and summaried from the views of the displacement vector field, the principal stress vector field, the principal stress path, as well as size and depth of plastic zone anddilate damage zone,and so is whether water pressure or not.The problems including the nature of deformation lag, the nature of failure lag and so on in the hard rockmass under high stress in the deep field are reasonably interpreted.Research on these issues provides the basis of information and theory for the smooth construction of Jinping II diversion tunnel.更多还原