【作者】 赵宝云；

【导师】 刘保县；

【作者基本信息】 西华大学 ， 岩土工程， 2008， 硕士

【摘要】 随着国民经济建设与国防建设的不断发展,地下开发不断走向深部,上千米乃至数千米深的矿井、巷道比比皆是。深部岩体因其所处的地球物理环境的特殊性和应力场的复杂性因而是工程中必需认真考虑和研究的课题。文章结合国家自然科学基金项目“深部开采煤岩动力灾害时间效应研究”,采用试验研究、理论分析相结合的方法,对深部灰岩的蠕变损伤特性进行了研究,得到了一系列具有现实意义的研究成果。首先对自然条件下深部灰岩进行了单轴和三轴压缩试验,分析了岩石应力-应变全过程曲线。通过单轴、三轴试验对深部灰岩基本特性进行研究,确定了深部灰岩基本力学参数。对深部灰岩试件进行了单轴三种不同荷载下的蠕变实验,并用声发射仪器收集岩石蠕变试验过程中的声发射信号,对三种荷载下深部灰岩蠕变损伤特性及对蠕变过程中声发射信号进行分析,讨论和总结了深部灰岩蠕变损伤、声发射特性。累积声发射振铃计数（C0unt数）-时间曲线与蠕变应变-时间曲线具有相同的趋势,代表了损伤的产生,声发射的强弱代表了损伤的程度。通过三轴蠕变试验,得出岩石微裂隙的成核、进一步扩展与岩石所受的偏压力、围压的大小有着密切的关系,岩石在相同偏压力下其稳态蠕变速率随着围压的增加而增大,微裂隙的扩展即损伤的演化随着围压的增加而进一步扩展:在相同围压下岩石的稳态蠕变速率、损伤演化亦随着偏压力的增加而增加。给出了岩石幂律型蠕变本构模型,并拟合得出该模型参数,通过与实验数据进行对比、分析表明幂律型蠕变模型可以用来较好的模拟该类岩石除第三阶段蠕变以外的蠕变行为。最后用幂律型蠕变模型对深部隧道进行了不同埋深情况下的数值模拟计算,分析了隧道围岩水平和竖向的位移变形及损伤特性,得出FuC^3D三维陕速拉格朗日程序可以很方便地模拟结构从弹性到塑性屈服、失稳破坏直至大变形的全过程。更多还原

【Abstract】 With the rapid development of the national economy and national defenses construction, underground exploitation depth trends much more deep levels. Kilometer or even several kilometers coal mines and tunnels can be found everywhere. Deep rock mass dues to it’s particularity of physical geography environment and complexity of it’s stress field has become a problem that must be carefully taken into consider and study in engineering practice. In this paper combined with "the study on coalrock dynamical disaster time effect of deep exploitation" which supported by National Natural Science Foundation of China, experimental study and theoretical analysis were used to study creep and damage property f deep limestone, gained a some Practical Significance research results.The experiment of deep limestone specimen were first carried out under uniaxial and triaxial compression load which under natural conditions, the complete stress vs strain curve of rock and it’s damage failure condition were analysised. Based on the study of basic mechanics properties of deep limestone, the basic mechanics parameters were determined.Creep experiment of deep rock specimen under three different uniaxil loads were carried out. At the mean time the acoustic emission signal was monitored by acoustic emission instrument at the process of compression as well. In the paper deep limestone creep damage properties under three different loads was analysised, meanwhile the acoustic emission during creep process was analysised too. At last was conclusion and discussion about the creep and damage of deep limestone and the properties of acoustic emission. The curve of accumulated acoustic emission ringing count vs time and the curve of creep strain vs time have same tendency, the accumulated acoustic emission damage generation and the AE signal level represents the degree of the creep damage.Through triaxial creep test shows that the rock microcrack nucleation and growth was relatively dependent on deviatoric loads and confining pressures. At the same deviatoric loads the steady creep ratio and damage evolvement increased with increasing of confining pressure. The expands of microcracks increased with increasing of deviatoric loads at same confining pressure. The power law type creep constitutive model was used in this paper and by the fitting got the parameters of this model. Compared with experiment data, result show that the power law type creep constitutive model can better simulate rock creep behavior except for the third creep stage.Finally, the power law type creep model was used to numerical simulation deep tunnel creep and damage property at different depth levels. The horizontal and vertical displacement deformation and damage properties of the tunnel wall rock have been analyzed. The result show that FLAC^3D three dimension Fast Lagrangian Analysis of Continua code can simulate then whole process of structure which from elasticity to plasticity yield, unstable failure up to larger deformation expediently.更多还原