边坡岩体力学参数的确定研究

发布时间：2018-06-14 20:00

本文选题：节理岩体边坡 + 力学参数　；参考：《重庆交通大学》2017年硕士论文

【摘要】：岩体力学参数取值之所以复杂且长期来成为许多学者的研究重点,因为岩体的内部发育了众多不同层次的结构面。众多不同层次结构面的存在,导致岩体宏观力学参数展现出不均匀性、各向异性和尺寸效应等特征。岩体力学参数的合理取值是边坡分析中的根本前提,也是边坡治理实际运用中十分关键的一点,直接体现在边坡工程的经济性和安全性。本文进行的研究内容主要包含以下几方面:(1)对边坡岩体质量系统CSMR分级进行分析,对主要的定量化参数岩石质量指标(RQD),不连续面间距,结构面方向F1,F2及F3,岩块强度,通过线性拟合得到连续函数,代替原来的离散函数的取值,细化了评分区间与对应的权值分配,降低了参数范围选择的人为因素影响。(2)对边坡岩体的节理裂隙进行统计,按照Monte-Carlo原理,生成岩体结构面裂隙网络的随机分布模型。分析了用选取特征迹长的方法确定数值分析模型的合理性,并得到表征单元体尺寸。(3)按照分形理论,边坡整体与局部分形维数相同,坡面上任意面积所对应特征迹长值与该边坡的特征迹长值有自相似的关系,分析了从小试件确定边坡力学性质的可能性。并且当分形维数相同时,不同尺寸节理岩体与特征迹长存在比例关系,得到不同尺寸节理岩体所对应的特征迹长,确定了节理裂隙统计的尺度与范围。(4)分析了边坡高度与表征单元体REV的关系,发现坡高对岩体强度存在弱化效应,并得到边坡高度与表征单元体特征迹长关系H=17.1R。提出了考虑坡高影响用小试件岩石强度结合表征单元体特征迹长估算岩体强度的方法。(5)结合工程实例采用细化的CSMR评分法,数值模拟试验方法、特征迹长法、宏细观损伤力学方法获得的岩体力学参数值,并进行了对比验证。
[Abstract]:The reason why the mechanical parameters of rock mass is complex and has been the focus of many scholars for a long time, because of the development of many different levels of structural planes in the internal rock mass. Because of the existence of many different structural planes, the macroscopic mechanical parameters of rock mass show inhomogeneity, anisotropy and size effect. The reasonable value of rock mass mechanical parameters is the basic premise of slope analysis and the key point in the practical application of slope treatment. It is directly reflected in the economy and safety of slope engineering. The research contents of this paper mainly include the following aspects: 1) the analysis of the slope rock mass quality system CSMR classification, the main quantitative parameter rock quality index, discontinuous plane spacing, structural plane direction F _ 1F _ 2 and F _ 3, the rock mass strength, the main quantitative parameter rock quality index, the discontinuous plane spacing, the structure plane direction F _ 1F _ 2 and F _ 3, the rock mass strength, By linear fitting, the continuous function is obtained, instead of the original discrete function, the distribution of the scoring interval and the corresponding weight is refined, and the influence of artificial factors on the selection of the parameter range is reduced. According to Monte-Carlo principle, the random distribution model of fracture network of rock mass structural plane is generated. The rationality of determining the numerical analysis model by the method of selecting characteristic trace length is analyzed, and it is obtained that the fractal dimension of the whole slope is the same as the local fractal dimension according to the fractal theory. There is a self-similar relationship between the characteristic trace length corresponding to any area on the slope and the characteristic trace length of the slope. The possibility of determining the mechanical properties of the slope by small specimen is analyzed. When the fractal dimension is the same, there is a proportional relationship between the jointed rock mass with different dimensions and the characteristic trace length, and the characteristic trace length of the jointed rock mass with different dimensions is obtained. The relationship between slope height and REV is analyzed. It is found that slope height has a weakening effect on rock mass strength, and the relationship between slope height and characteristic trace length of unit is obtained. Considering the influence of slope height, a method of estimating rock mass strength by combining rock strength of small specimen with characteristic trace length of unit is proposed. The method of CSMR scoring, numerical simulation test and characteristic trace length are used to estimate rock mass strength in combination with engineering examples. The mechanical parameters of rock mass obtained by macro-meso-damage mechanics method are compared and verified.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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