【作者】 庄宁；

【导师】 朱合华； 崔茂玉；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 裂隙岩体中存在着大量的裂隙，这些裂隙的存在形成了它不同于其它均匀介质的复杂的力学特性和渗流特性。运用传统的渗流理论来分析岩体裂隙中水的渗流，难以反映渗流应力耦合过程中裂隙的萌生扩展过程，因此采用新的理论和方法来研究裂隙岩体渗流应力耦合特性，已成为岩石水力学研究中的热点和难点之一。 研究裂隙岩体的渗流耦合过程，揭示其在渗流应力耦合状态下裂隙的扩展萌生规律，探求裂隙岩体在渗流耦合状态下由于其裂隙的扩展贯通而导致破坏的机理，了解裂隙岩体失稳破坏的原因。对于提高岩土工程设计水平，评价工程安全性能等，均有重要的理论意义和工程实用价值。 本文以颗粒流理论为基础，运用PFC软件从细观力学角度研究了渗流耦合过程中裂隙岩体中裂纹的扩展萌生规律，并以此为基础运用宏观断裂力学等理论推导了渗流耦合过程中裂纹的扩展萌生公式。然后将裂纹的扩展公式代入渗透系数表达式，作为渗流场应力场之间耦合的桥梁，建立裂隙岩体的渗流应力耦合数学计算模型。主要工作如下： 1、运用基于颗粒流理论的PFC软件从细观上对裂隙岩体在无水渗流情况下裂纹的扩展进行了模拟，重点分析了不同几何位置以及加载方式下两裂纹的扩展机制。并和实际室内试验相比较，两者结果较接近，以此验证了PFC软件模拟裂隙扩展的可行性。同时分析了PFC软件细观参数对宏观试验结果的影响。 2、从细观上模拟了裂隙岩体中单条斜裂纹在渗流应力耦合状态下的扩展规律，分析不同水压力和侧压力对单条斜裂纹的影响。然后重点对裂隙岩体中两裂纹的扩展机制进行了研究，着重分析不同水压力对两裂纹扩展模式的影响。同时通过工程实例，数值模拟了隧道开挖过程中有水压和无水压状态下，隧道周围裂纹扩展的规律。 3、以第二点为基础，运用断裂力学等宏观力学理论，推导了岩体中裂纹的扩展贯通的理论公式，得出裂纹在渗流耦合下的裂纹扩展长度公式，并代入渗透系数与裂纹长度的关系式，以该公式作为渗流场和应力场之间的耦合桥梁，提出本文的裂隙岩体渗流应力耦合的数学模型，并提出了宏观数值实现方案。更多还原

【Abstract】 There are many cracks which offer good condition for groundwater’s motion, rest and storage in the crack rock mass. The cracks cause rock mass’ complex mechanic and seepage property which is different from homogeneous material. It is difficult to show the crack’s propagation in the seepage-stress coupling process by traditional seepage theory. So using the new theory and method to research seepage-stress coupling character of crack propagation becomes an attracted and challengeable difficulty in the domain of rock hydraulics.Reaching the seepage-stress coupling process of crack rock mass is very important to disclose crack’s initiation rule, study crack’s propagation and run-through mechanism and understand the rock mass’ destabilization and damage reason. This also has utmost theory and engineering significance to improve geo-technical engineering design level, appraise engineering security and optimize the construction of tunnel and dam in the seepage-stress coupling process.PFC software is used to research crack’s initiation and propagation from the mesoscopic aspect by the theory of particle flow code. The crack’s initiation and propagation formula is established by macroscopic fracture mechanics. The formula is as the bridge of stress field and seepage field. By this bridge the seepage-stress coupling mathematics model is established. In details, this dissertation includes:1. The crack’s propagation rule of crack rock mass is simulated by PFC software from mesoscopic without seepage. Two cracks propagation mechanism is analyzed in geometric position. The results of simulating are compared to laboratory results and they are very close. This proves that the PFC software is feasible to simulate crack propagation. At the same time the effect of mesoscopic parameter to macroscopic parameter is also analyzed.2. The single diagonal crack’s propagation rule is simulated in the condition of seepage-stress coupling. The effect of different water pressure and lateral compression to single diagonal crack’s propagation rule is studied. And two cracks’更多还原