【作者】 范云冲；

【导师】 胡卸文；

【作者基本信息】 西南交通大学 ， 地质工程， 2003， 硕士

【摘要】 本文在阐明锦屏一级水电站普斯罗沟坝址工程地质条件的基础上，得出了影响坝基岩体质量的主要因素为：岩性、岩体结构、岩体紧密程度、风化卸荷、结构面性状及深拉裂缝发育状况，且深拉裂缝对岩体质量的影响是锦屏一级坝基岩体质量分级有别于其它水电工程的独特之处。本文接着运用单因素分级法和多因素分级法对坝基岩体质量进行了详细的分级研究。单因素分级包括岩石质量分级、风化卸荷程度划分、岩体结构分级、岩体纵波波速分级等；多因素分级法包括MZ分级（修正的Z系统）、RMR及Q系统分级。MZ分级法是本文提出的一个新的岩体质量分级方法，它通过对影响锦屏坝基岩体质量的四项主要指标：岩石湿抗压强度R_c、岩石质量指标RQD、结构面性状系数（节理面粗糙度系数J_r与节理面蚀变度系数J_a之比）及岩体完整性系数K_v求乘积来综合确定坝基岩体质量等级。 在坝基岩体质量分级结果的基础上，本文重点研究了MZ分级结果与野外分级、RMR分级及Q分级结果间的相关关系，分析表明MZ分级结果与野外分级结果接近，与RMR分级及Q分级结果相关性显著。 作为成勘院科研项目“锦屏一级水电站坝区岩体质量分级及其物理力学参数取值研究”的一部分，本文在完成上述分级后，重点对各级岩体的变形及剪切强度参数进行了统计分析，得出了各级岩体变形和剪切强度参数建议值。分析表明岩体变形模量E₀与MZ、K_v相关性较好，同时MZ分级法还具简单、直观、参数易于获取等优点，所以MZ分级法是一种非常实用的岩体质量分级方法。 为进一步研究坝基岩体的工程力学特性，本文根据Ⅱ线及Ⅱ₁线平硐岩体质量分级结果，同时按照“混凝土拱坝设计规范”(SD_145-85)对坝基岩体的要求初步确定了大坝建基面的开挖深度。最后运用平面有限元方法，以Ⅱ₁剖面为例，按上述建基面开挖深度及各级岩体力学参数取值结果，对坝基开挖前后坝基开挖边坡的应力及应变场进行了数值模拟，对边坡岩体可能的变形破坏特征作了评价，分析表明按岩体质量分类所确定的建基面开挖深度是合理的。更多还原

【Abstract】 Based on the discuss of the engineering geological conditions of the Pusylog dam site of the Jinping arterial power station, The paper have found the main factors that affect the rock mass quality of dam foundation: lithology, rock mass structure, rock mass compactness, weathering, the properties of discontinuities and the effect of the deep crack, especially the deep crack is the particular thing other than the other power station. The paper then study on the classification of rock mass quality of dam foundation through the single factor classification and the multi-factors classification methods. The single factor classification includes lithology classification, weathering and stress release degree classification, rock mass structure classification, wave velocity classification etc. The multi-factors classification included the MZ (Modified Z System), the Rock Mass Rating (RMR) and the Rock Tunnelling Quality Index(Q) classification. The MZ system works through study the four main factors that affect the rock mass quality of dam foundation: the Strength of intact Rock material (Re), the Rock Quality Designation (RQD), the properties coefficient of discontinuities( the joint roughness number Jr/the joint alteration number Ja) and the intact index(Ky).Based on the classification results of the rock mass quality of dam foundation, the paper study in stress the relativity of the MZ values and the other classification results. The analysis results show that the MZ classification results are close to the field classification results, and are notable to the RMR system and the Q system classification results.As a part of the scientific research item of CHIDI that the study on the rock mass quality classification of dam foundation and corresponding mechanical property of the Jinping arterial power station, when have achieved above results, this paper provide the reference values of deformation modulus and shear strength of rock mass and discontinuities on basis of field testing data. The correlation analysis shows that the close correlativity of the MZ values and the mechanical parameters of rock mass, for example deform modes E0, so MZ classification is a very effective method.In order to lucubrate the mechanical character of the engineering rock mass of dam foundation, this paper pilot study the excavating depth of the available foundation through grading the rock mass quality of the II and II i section, meanwhile judge the availability of the rock mass of dam foundation according to the design criterion of the concrete arc damCSD145-85). In the end ofthis paper the planar finite element method is used to simulate the stress field and strain field of the slope of the II i section under deadweight before and after the dam foundation has been excavated. And then evaluates the possible destroy areas. The analysis shows the excavating depth of the available foundation is reasonable through grading the rock mass quality.更多还原