渗透压作用下茅口灰岩力学特性研究

发布时间：2018-06-03 01:47

本文选题：茅口灰岩 + 流固耦合　；参考：《湖南科技大学》2015年硕士论文

【摘要】：渗流场中岩体的力学特性和应力场下岩体的渗透规律是岩石力学学科领域的前沿方向。在渗流场中的岩体,一方面由于外部荷载的作用,岩体内部应力进行重分布,从而影响岩体的结构,改变岩体中水的作用强度、范围及形式;另一方面,不同应力状态下岩石内部结构不同,导致岩石渗流路径不同。岩体渗流一应力耦合理论在采矿工程、水利水电领域、地铁建设领域等有重要的指导意义和广泛的应用前景。本文以国家自然科学基金项目(51174088):二次卸荷条件下岩体流变损伤破坏机理研究、国家自然科学基金项目(51274097):茅口灰岩隐伏承压溶洞围岩时效破断-滞后突水机理研究为依托,在茅口灰岩流固耦合试验和强度试验基础上,研究了不同围压渗透压作用下茅口灰岩的强度特性、变形特性、渗流特性及破坏特征,揭示了渗流—应力作用下茅口灰岩的各种特性的变化机制。主要研究内容有:(1)基于流固耦合试验和强度试验,求解了岩石的各强度值及其参数,分析研究了围压、渗透压对茅口灰岩的峰值强度、起裂强度和损伤强度影响;分析了渗透压对茅口灰岩抗剪强度及其参数的影响、对岩石变形特征及各变形参数的影响、对破坏特征的影响;结合断裂力学理论探讨分析渗透压作用下,茅口灰岩的起裂强度变化机制,得出渗透水压与裂隙初裂强度成负相关关系;(2)研究茅口灰岩渐进破坏阶段渗透压差演化规律,将压缩破坏过程中的渗透压差?P变化规律划分为四个阶段,并分析了不同围压对?P的影响,基于采集的渗透压差数据,计算出岩石的峰前渗透系数,并研究了不同围压作用下的渗透特性;基于Kozeny-carman方程建立渐进破坏过程渗透性与体积应变的关系,并将试验所得的数据与理论模型进行验证;(3)基于试验数据,通过引用孔压弱化系数,提出两种考虑渗透压作用的岩石强度准则,并对两新准则进行对比研究。将新准则和其他常用强度准则进行比较分析,验证新准则的准确性与适用性。
[Abstract]:The mechanical properties of rock mass in the seepage field and the law of permeability under stress field are the frontiers in the field of rock mechanics. On the one hand, the rock mass in the seepage field, on the one hand, redistributes the internal stress in the rock mass due to the effect of the external load, thus affecting the structure of the rock mass and changing the strength, scope and form of the water in the rock; on the other hand, The rock internal structure is different under different stress state, which leads to different seepage path of rock. The theory of stress coupling of rock mass seepage has important guiding significance and wide application prospect in mining engineering, water conservancy and hydropower field, subway construction field and so on. In this paper, the State Natural Science Foundation Project (51174088): rock mass rheology under the condition of two unloading Research on damage and destruction mechanism, National Natural Science Fund Project (51274097): Study on the mechanism of aging fracture and lagging water inrush in the hidden confined karst cave of Makou limestone, based on the fluid solid coupling test and strength test of Makou limestone, the strength, deformation and seepage characteristics of mamakou limestone under different confining pressure and osmotic pressure are studied. The main research contents are as follows: (1) based on the fluid solid coupling test and strength test, the strength and parameters of rock are solved and the peak strength of the peri pressure and osmotic pressure on the peak strength and the damage strength of the maotun limestone are analyzed and studied. The influence of osmotic pressure on the shear strength and its parameters of Maotu limestone, the influence on the rock deformation characteristics and the deformation parameters, the influence of the damage characteristics, and the mechanism of the change of the breaking strength of the Makou limestone under the action of osmotic pressure are discussed in combination with the fracture mechanics theory, and the negative correlation between the seepage pressure and the crack initial crack strength is obtained. (2) research on the relationship between the seepage pressure and the initial crack strength of the fissure. The evolution law of osmotic pressure difference in the progressive failure stage of Makou limestone is studied, and the variation law of osmotic pressure difference? P in the process of compression failure is divided into four stages, and the influence of different confining pressure on P is analyzed. Based on the data collected by the osmotic pressure difference, the permeability coefficient of the rock is calculated and the permeability characteristics under different confining pressure are studied; based on K The ozeny-carman equation establishes the relationship between the permeability and the volume strain of the progressive failure process, and verifies the data obtained by the experiment and the theoretical model. (3) based on the test data, two kinds of rock strength criteria for osmotic pressure are proposed by reference to the pore pressure weakening coefficient, and the new criterion is compared with the new criterion and the others. Common strength criteria are compared and analyzed to verify the accuracy and applicability of the new criteria.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU452

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