【作者】 胡斌；

【导师】 张倬元； 陶连金；

【作者基本信息】 成都理工大学 ， 地质工程， 2002， 博士

【摘要】 数值模拟方法在研究地下洞室围岩稳定性方面具有十分明显的优势，已日益成为稳定性定量评价中不可或缺的重要方法。本文紧密结合溪洛渡水电工程大跨度、高边墙复杂地下厂房洞室群，施工开挖过程中和开挖后围岩稳定性研究这一重大课题，在详尽的野外地质调查工作和对大量基础地质资料的整理与分析基础上，以目前国际工程地质界公认的最新通用软件FLAC^3D2.0版作为基本计算工具，从整个坝区地应力场的研究开始，通过动态数值仿真分析这一新的模拟思路，系统地研究了深切峡谷区地应力场多阶段的特征和演变规律，进而对左、右岸地下厂房洞室群开挖全过程中围岩应力场、变形场和塑性破坏区的变化特征，进行了全过程动态数值仿真研究，并详细讨论了围岩质量、初始地应力场、施工开挖顺序对大型地下洞室群围岩稳定性的影响。通过上述研究，本文取得了以下新的进展和认识： （1）从方法论上，进一步拓展并丰富了原有的数值模拟思路。明确地提出了动态数值仿真分析的三个基本组成部分，即：仿真计算模型的建立——仿真过程设计——结果输出的控制与分析。每一部分都与相应的工程地质条件和岩体变形破坏的研究紧密结合在一起，动态数值仿真是整个地质作用过程和人类工程活动过程的模拟，是计算结果与不断获得的野外地质信息和岩体变形破坏迹象反复耦合的交互式动态分析过程。 （2）在FLAC^3D软件的提供的十二种初始单元网模型（Primitive Mesh）的基础上，独立地开发了FLAC^3D前处理程序(FLAC^3DPre-processing Package)，成功实现了建模自动化，极大地提高了工作效率，并且把真实地形、地貌反映到计算模型中，大大提高了计算的精确度和可靠度，在建模技术上有了新的突破，其设计思路也值得同类软件借鉴。 （3）按照动态数值仿真新思路，运用FLAC^3D软件及FLAC^3DPre-processing Package，建立了深切峡谷区仿真计算模拟，设计出了较为合理的仿真过程方案，有效地控制了结果的输出，重现了峡谷形成过程中四个发育期的地应力场特征，并对峡谷区地应力场的演变过程进行了动态的系统研究与分析，其研究成果对分析、解决溪洛渡深切峡谷区地应力场存在的难题，提供了可靠且有力的依据。 （4）按照动态数值仿真新思路，以地下洞室群围岩的工程地质条件和工程设计方案为依据，系统研究了大跨度、高边墙地下洞室群开挖完成后围岩的二次应力场、变形场和塑性破坏区的分布特征，开挖过程中围岩的应力场、变形场和塑性破坏区的变化特征。全面总结了溪洛渡水电站左、右岸地下厂房洞室群围岩应力，变形和破坏区的分布特征和变化规律，为洞室群稳定性评价和工程施工设计提供了基础资料和理论依据。 （5）密切结合溪洛渡右岸地下厂房洞室群的工程地质条件和工程设计，首次深入地讨论了围岩质量、初始地应力场、开挖顺序对大型地下洞室群围岩稳定性的影响。 （6）通过对实测地应力资料较深入的分析与研究，概括出溪洛渡深切峡谷区地应力场的基本变化规律。认为该峡谷区中，谷河底部最大、最小水平应力量值总体上具有随深度增加而线性增大的特征，但其线性方程的系数a₁、a₂、b₁、b₂，随地表高程的低高或者说 成都理工学院工学博士学位论文，20（）河谷侵蚀厚度的深浅而变化；岸坡山体中仅存在应力降低区和应力相对平稳区而没有明显的应力增高区，应力降低区与应力相对平稳区的分界线在水平埋深135～165m之间。在应力降低区，地应力的量值随水平埋深的增加而明显增大；在应力相对平稳区除a。变化较大外，a。、。；量值相对平稳。通过动态数值仿真分析，其结果也得到了验证。更多还原

【Abstract】 Today, numerical simulation analysis is more and more important in the engineering geology research field, especially in the quantitative evaluation. Relating closely to the main problem of the high sidewall and wide span underground cavities excavation stability of Xiluodu hydroelectric project, the evolution characters of geo-stress field in deep-cutting gorge and the whole features of the stress field, strain field and plastic failure zone around the underground chambers after excavation are studied systematically in the dissertation, based on a great deal of data gathered in field investigation and taking the FLAC3D V2.0 software as basic computation tools. Meanwhile, In the course of research, the new methods of dynamic numerical simulation are summarized and applied. Furthermore, the effects of Rock Mass Qualities, initial geo-stress field and Excavation Procedure on Surrounding Rock Mass Stability are discussed. The main achievement in the paper can be drawn as follows:(1) As a most important achievement, the concepts of numerical simulation are expanded. Three composition parts of dynamic numerical simulation are put forward clearly e.g., building the dynamic numerical simulation model, designing the simulation process and the output controls of the simulation computation results. Each part should connect tightly with the study results of engineering geological condition and the deformation and failure of rock mass in the investigated area. The dynamic numerical simulation should replay both the whole course of geological process and real human activity. It is an interactive dynamic analysis course that the computation results are coincident to the new engineering geological messages and changeable features of the rock mass deformation and failure.(2) As an important outcome in the paper, the author developed the FLAC3D Pre-processing package in the basis of the 12 primitive meshes provided by FLAC3D, which can construct the calculating model containing the actual topographic and geological features of the investigated area automatically. Thus, it can not only improve the calculating precision, but also decrease time consuming greatly. And the design method of the program is a good help to the same kind of programs.(3) According to the new methods of dynamic numerical simulation analysis, the computation model of the deep cutting gorge is contracted with FLAG30 software and FLAG30 Pre-processing package, the reasonable simulation course is designed and the calculating results is controlled effectively. Finally, the forming process and the evolution features of the 4 stages geo-stress field evolution in Xiluodu gorge are displayed in the paper, from which the variable regulations are analyzed and summarized systematically. These achievements can be regarded as creditable evidences for technocrats to solve some problems of geo-stress field in Xiluodu area.(4) According to the new methods of dynamic numerical simulation analysis and resting on the engineering geological conditions of surrounding rock mass and the project design, the threenumerical simulation results are obtained, from which the author analyze systematically the distribution features of stress field, strain field and plastic zone in the surrounding rock mass of the underground cavities after the excavation and also the variable features of stress field, strain field and plastic failure zones in the surrounding rock mass of the underground cavities in the course of excavation. And that, the variable regulations of stress field, strain field and plastic failure zones in the surrounding rock mass of the underground cavities are summarized for the right and the left bank of underground chambers. The main results can be taken as the basic data and the theoretical proofs to evaluate cavities stability and guide the correct excavation.(5) Relating closely to the engineering geological condition and the project design of the underground cavities in the right side bank of Xiluodu, the effects of Rock Mass Qualities, initial ge更多还原