【作者】 唐浩；

【导师】 朱传云；

【作者基本信息】 武汉大学 ， 水工结构工程， 2004， 硕士

【摘要】 在水利水电工程建设中,地下工程开挖占有重要地位。诸如:导流洞、引水洞、交通洞、试验平洞、灌浆洞以及水电站地下厂房洞室群开挖等。由于我国能源、交通、国防发展的需要,特别是水电能源的开发,使得大型和超大型地下工程规模已成为发展的主要方向。伴随着装机容量的增大,地下厂房及相关洞室的规模越来越大,以大跨度、高边墙、多交叉以及结构复杂为特征。大型复杂地下厂房洞室群的开挖,势必引起洞室群围岩位移场和应力场的调整,过大的变形和应力集中都会造成围岩的破坏,对洞室的稳定产生影响。另一方面,钻爆法仍然是地下工程开挖的主要施工方法,围岩在动态荷载作用下的振动响应也是一个不可忽视的问题。因此,长期以来,大型水电站地下洞室围岩稳定性评价一直是工程界研究的重要课题。 本文的主要工作分为以下三个方面:首先从洞室群的开挖,导致围岩应力场重新分布影响洞室群稳定性出发,采用FLAC^3D建立了数值模型,模拟施工开挖过程,研究了复杂洞室群围岩的开挖变形形态和应力状态,分析了围岩塑性区分布及地下厂房洞室群围岩的稳定性,并对主厂房、主变室、调压井顶拱进行了加固处理;其次,在爆破荷载对围岩稳定影响的数值模拟计算方法方面,目前的研究工作大多是使用二维有限元数值计算方法,而LS-DYNA3D大型有限元系统为解决三维非线性问题提供了可能,目前己能应用于弹塑性问题处理爆炸冲击荷载对结构的破坏等,因此本文引入三维动力有限元方法,进行了数值建模分析,计算出不同爆破方式、不同爆破部位产生的以及邻近爆破施工所产生的爆破振动作用下,地下厂房洞室群围岩结构的动应力场、速度场和位移场的分布规律;对各种因素如何影响洞室群围岩稳定问题进行了深入的理论分析和定量计算,并将它们与实际爆破施工相结合,得出了若干结论。最后,针对性的讨论了近区应力波振动效应、中远区振速高程放大效应、计算结果与实测数据对比分析,参数敏感性分析等一系列重大技术问题。本文结合数值分析的成果,探讨了在地下工程的洞室群开挖中,两类安全问题,为今后的实际工程提供借鉴和参考。更多还原

【Abstract】 In the construction of many huge hydroelectric engineering, there are many underground engineering such as diversion tunnel, access tunnel, test direct tunnel, grouting tunnel, large-scale underground cavern group and so on.Because of development of energy,traffic and national defense, especially, the development of hydropower, make the scale of large-scale and ultra large-scale underground project already become the main direction of development. With the increase of the capacity of hydropower station, the scale of underground powerhouse and the relevant cavern group are larger and larger, characterized of large span, high sidewall, multiple cross-over and structure-complicated, large-scale underground cavern group excavation, certainly will cause adjustments of deformation fields and stress fields of surrounding rocks of underground cavern group,excessive large deformation and stress concentration will also fail surrounding rocks of underground cavern group, influence on cavern group stability. On the other hand, drilling and blasting are main construction method of the underground project excavation, it can’t be ignored that the vibration response of surrounding rocks on dynamical loads. So, for a long time, it has been an important subject that the surrounding rocks stability evaluation of large-scale power station in geotechnical engineering.The works of this article include three parts as followed :Firstly, As view from the cavern group excavation causes surrouding rock stress redistribution influence stability of cavern group,this paper build numerical model by three-dimension fast Lagrangian moethod (FLAC^3D) ,the pattern of deformation caused by excavation and stress state in surrounding rocks of the chamber group under complex conditions are researched.The distribution of plastic areas and stability of surrounding rocks are analyzed. And the bolting is performed to support the vault of main power house, main substation,surge shaft.Secondly,considering it mainly make research by means of the two dimension FEM in the passing research in numerical simulation of the stability of surrounding rocks under blasting vibration loads ,and now the commercial FEM analysic software LS-DYNA3D can solve the three-dimension non-linear structure’s dynamic questions,so by means of the software,this paper introduce three-dimension elastic-plastuc dynamic FEM to dynamic calculation of blasting and analyzes stablity of surrounding rocks under blasting vibration loads, calculate the laws of stress field,velocity field and displacement field of surrounding rocks on condition of various blasting method,various blastingpostion and near blasting.Finally, Stress wave vibration effect in near, the magnifying effect of velocity along the height of rock in the far field, result of calculation and survey datum comparision and analyse, parameter sensitivity that a series of great technological questions are analyzed. This paper results of combination numerical analysis, has discussed two kinds of safe problems in the cavern group excavation of underground engineering, offer reference for the practical project in the future.更多还原