【作者】 杨峰；

【导师】 陈奇；

【作者基本信息】 中国地质大学（北京） ， 岩土工程， 2011， 硕士

【摘要】 面对我国石油消费的总量不断提高,进口量逐年递增的局面,为保障国家能源安全,满足经济发展的需要,启动战略石油储备基地建设已迫在眉睫。各种储油方式中,地下水封储油洞库是安全性高、经济性好的一种储油形式。惠州地下石油储备库是目前世界上拟建的设计规划库容量最大的超大型地下水封储油洞库群。该类工程在我国仍缺乏相关的工程实践,对此类大规模的洞室群开挖过程中的围岩稳定性分析与评价,是一个亟待解决的问题。本文以惠州地下储油库为研究对象,应用FLAC3D数值模拟软件,对洞室群设计、开挖方案优化、开挖过程围岩稳定性分析与评价等几个方面进行了深入研究,具体工作成果如下:(1)库址区岩体物理力学参数修正,运用复变函数理论推导出基于弹性力学方法的直墙圆拱型洞室洞周切向应力计算公式。(2)利用有限差分数值模拟软件FLAC3D进行数值模拟计算,提出各主洞室之间以及主洞室与施工巷道之间的合理间距;比选出洞室群整体施工顺序最佳方案,对洞群效应有了深入认识。(3)采用复变函数解析方法对不同等级围岩情况下的单洞稳定性进行了比较分析,对于Ⅱ级、Ⅲ级岩体,拱顶与底脚处存在围岩稳定性问题。此外,采用FLAC3D软件对洞群开挖全过程进行了仿真模拟,结果表明三级台阶分层推进施工方法对于惠州储油洞库工程这种大断面洞室比较适宜。(4)采用流固耦合方法模拟洞群开挖,开挖过程中应力场的分布与不考虑地下水的情形基本一致,但应力值有所减小;位移场方面则体现为拱顶下沉量成倍增加。渗流条件下,洞周围岩塑性区的扩展,受地下水排水速度与时间的控制,排水不利时,塑性破坏区急剧增加,充分排水后,塑性区范围则大幅度减少。(5)惠州库址区,降雨充沛,地下水补给较为充分,有利于水封环境的形成。在渗流条件下,洞室群的开挖将改变渗流场的分布,洞周形成区域性降落漏斗,整体水位也有较明显的下降。模拟结果显示,开挖完成后洞周无法达到安全运营所需的孔隙水压,有必要在洞顶上方布置水平水幕系统与竖直注水孔。更多还原

【Abstract】 Facing of the oil consumption toal amount and the oil imports increased year by year.It’s immediately to start the consttuction of strategic oil reserve base to meet the needs of economic development and protect national energy security. In various kinds of storage methods, water sealed underground oil storage caverns is more safer and economicaly .The planning of Huizhou water sealed underground oil storage caverns is the lagest storage caverns in designing till this year.Such engineering project is still lack of the engineering practice in China. The analysis and evaluation of surrongding rock in the process of large caverns excavating is a serious problem to solve.This thesis takes Huizhou water sealed underground oil storage caverns as study object,using the numerical simulaton software FLAC3D,does further researches on the design of caverns ,the optimization of excavation project, analysis and evaluation of stability of surrounding several.The specific work as follows:(1)Corrected the physical and mechanical parameters of rock in the library site region. Using complex-variable function theory based on elastic mechanics method is deduced the straight wall round arch type cavern hole weeks tangential stress calculation formula.(2)Calculatied with the finite difference numerical simulation software FLAC3D,propesed the appropriate distance between the main tunnels and the appropriate distance between the main tunnels and the roadway. Elected the best construction sequence of the tunnels.Owned a in-depth understanding about group tunnels effective.(3) Using the complex function analytical method,Based on signal hole,anslysis the stability of surrounding rock under different levels of rock grade. For the gradeⅡ、Ⅲrock,the rock at foot corner and arch existed stability problems.In addition,Simulated the whole process of tunnels excavation with the software FLAC3D.The results show that three steps forward excavation method is appropriate for this large underground cavern project as Huizhou.(4) Using fluid-solid coupling method for the process of tunnels excavation. In the excavating procession,the distribution of stress field is similar as the situation which not consider the case of groundwater,but the stess has been reduced; the displacement field is reflected in terms of subsidence into the multiplied increased. In flow conditions,the expansion of the plastic zone around the rock, controled by the speed and time of water drainage.Drainage bad,the plastic zone increased dramatically, and fully drained,the plastic zone is significantly reduced.(5) The area of Huizhou water sealed underground oil storage caverns,abundant rainfall,groundwater recharge is adequately. It’s conducive to the formation of water-sealed environment.Seepage conditions,the excavation of caverns will change the distribution of seepage field, At the hole week will form a regional cone of depression, the overall water level decline is also obvious.Simulation results show that the pore water pressure can not reached the required to operated security after the constructions project completed. It is necessary to arrange the water curtain system and vertical water injection holes in the roof above.更多还原