【作者】 崔中兴；

【导师】 仵彦卿；

【作者基本信息】 西安理工大学 ， 岩土工程， 2005， 博士

【摘要】 应力场、渗流场耦合系统是实际工程中经常遇到的问题,因此,研究水-岩相互作用的力学机制和岩石内部细观损伤演化过程及其破裂模式,从细观到宏观两方面揭示出水-岩相互作用的损伤扩展机理,揭示岩石的细观损伤过程及其破裂模式,揭示水-岩相互作用的内在力学机制,是解决重大工程和地质灾害防治的关键的基础科学课题,具有重要的科学意义及应用研究价值。利用SIEMENS SOMATOM plus 型X射线螺旋CT机和中低压多功能岩土渗流实验装置,以中等胶结程度、透水性较好的陕西铜川地区的砂岩为研究样本,在三轴应力状态下,对砂岩试样的应力与渗流相互作用的损伤全过程进行了三维实时CT动态观测。在第二章节里,对砂岩进行了干燥状态下的砂岩试样的宏观应力应变特性试验和不同渗透水压力作用下的砂岩试样的宏观应力应变特性试验。提出了围压对试样强度和变形的折减率与渗透水压力对试样强度和变形的折减率的基本概念及其数学表达式。在第三章节里,对砂岩试样进行了水-岩相互作用过程的三西安理工大学博士学位论文亩亩亩亩亩亩亩面亩亩亩亩亩亩亩亩亩亩亩亩百亩百面亩亩万亩亩亩亩亩亩百亩亩亩百面亩亩巨亩百亩百亩亩亩苹奋百声亩亩亩亩亩i维实时Cl,观测。对砂岩试样进行了实验过程中密度变化的数学分析,导出了在渗流状态下基于细观分析的砂岩试样密度损伤增量的数学表达式,研究分析了砂岩应力应变状态与Cl,数变化的相关关系、围压对Cl,数变化的影响以及渗透水压力与C江,数变化的相关关系。 在第四章节里,进行了基于细观分析的砂岩隙宽宽度变化的数学分析。提出了砂岩裂隙隙宽变化与Cl,数变化的相关关系;提出了基于Cl,数值的变化求解砂岩试样裂缝宽度的计算公式;提出了基于Cl,图像求解砂岩试样裂缝宽度的计算公式;给出了渗透水压力与砂岩裂缝宽度变化的相关关系及其数学表达式。研究结果表明除了应力能对岩石造成变形损伤外,渗透水压力也会对岩石造成变形损伤,而且渗流与应力状态的相互作用影响很大,渗透水压力对试样的强度和变形的影响是显著且十分灵敏的。关键词:CT实时观测,宏观应力应变,细观损伤分析,密度损伤增量,渗透水压力,裂隙隙宽变化,强度与变形折减率更多还原

【Abstract】 The coupling system of stress field and seepage flow field is a common problem occurred in practical engineering. For this reason, it is necessary to study mechanical mechanism of water-rock interaction and evolution process of inside rock micro-damage as well as broken patterns, whereby the damage expansion mechanism of water-rock interaction, the process of rock micro-damage process and the broken patterns, as well as internal mechanical mechanism of water-rock inter-reactions are indicated from the micro- and macro-aspects. This is the research project in basic science for the solving of the key problems in priority engineering works and prevention and control of geological disasters, and is of the important scientific significance and practical application values.SIEMENS SOMATOM plus Type X-Ray screw CT machine and multi-purpose geo-tech seepage flow testing device with medium and low pressure are adopted in the tests. The sandstone with medium cementation and better permeated properties from Tongchuan area in Shaanxi can be served as research specimens. In the state of tri-axial stress, the 3-D real time CT dynamic observation and measurement of the stress of sandstone samples and the whole damaging process of seepage flow inter-actions are made.In sections of chapter 2, the tests of macro-stress and strain properties of sandstone samples in the state of dry sandstone as well as the macro-stress and strain properties of sandstone samples under the action of permeable water pressures are carried out, whereby the basic concept and mathematical equations for the confining pressure upon the strength of testing sample and depreciation-reduction rate of deformation as well as permeable water pressureupon sample strength and depreciation-reduction rate of deformation are suggested.In sections of chapter 3, the 3 -D real time CT observation and measurement of water-rock interactions are made of sandstone samples. Also, the mathematical analysis of density variation in sandstone sample is made in the testing process, whereby the mathematical equation is derived in the state of seepage flow and based on the micro-analysis of the increments of sandstone sample density damages. And at the same time, the correlative relations among sandstone stress and strain state and CT number variations as well as the correlative relations between the effect of confining pressure upon CT number variations and permeable water pressure and CT number variations are analyzed.In sections of chapter 4, the mathematical analysis of the width variations in sandstone porosity widths is made based on micro-analysis. Accordingly, the correlative relations between variations in crack width of sandstone cracks and CT number variations are advanced; the formula for calculating the crack width of sandstone sample cracks is suggested on the basis of CT number variations; the formula for calculating the crack width of sandstone sample cracks is presented on the basis of CT number images; and the correlative relations between the permeable water pressure and the width variations of sandstone cracks and the mathematical equation are given in this thesis. The research findings indicate that apart from that fact that stress can cause deformation damages to rocks, permeable water pressure can also can cause deformation damages to rocks; and that also, the inter-reactions between seepage flow and stress state may have great effect upon rocks. Accordingly, permeable water pressure force can have a remarkable and sensitive effect upon the strength and deformation of sandstone samples.更多还原