【作者】 王亚军；

【导师】 晏鄂川；

【作者基本信息】 中国地质大学 ， 岩土工程， 2013， 博士

【摘要】 液化气是液化石油气的简称,也叫液态烃,是在气田或油田的开采及石油炼制过程中产生的一部分气态烃类,经液化后分离出干气而得到的可燃液体。它是一种清洁、高效、低成本的优质能源,除了作为化工原料、发电燃料以外,在工程领域也得到了广泛的应用。世界各国都已将液化石油气能源作为战略能源,随着世界各国工业进程的不断深入发展,各国对液化气能源的储备更加重视,在世界各地修建了许多各种类型的油气储库,而储气库的类型也慢慢由刚开始的地上储气库逐渐转为地下洞室储存。地下空间作为一种资源已经得到业界的广泛认可,在相关规划和调研的基础上,如何充分利用该资源类型来建设地下储库也得到大量研究,其中的一个主要利用方式就是利用已有的或者人工挖掘的空间,而其中应用最多的大型储库是油气储库。液化石油气地下洞室存储目的可以分为国家战略储备、商业存储和个人存储。液化气的战略储备一般是国家直接投资或以其他方式拥有和控制一定数量的液化气,属于保障能源安全的一种重要手段,可以保证在发生战事、大规模禁运等非常时期,液化气的储备可应对国际液化气市场的剧烈动荡,从而减缓因此可能给国民经济带来的冲击。地下水封液化气库是埋藏在一定的地下水位以下,依靠地下水的压力来封存液化气,一般建造在围岩条件较好的地区,洞室围岩在不做支护或者较少支护的条件下,裸洞储存液化石油气。目前,国内建设的地下水封液化气库数量不多,可供借鉴和参考的类似的设计和施工经验很少,尚处于试验摸索的阶段,还有许多技术问题须进行深人研究。由于液化气属于易燃易爆物品,对其进行封存,不仅要求洞室处于稳定的地下水位以下,还对地下洞室的结构设计有较高要求,要求科学合理的选择结构设计参数以保证洞室围岩的稳定和储气库的安全运行。因此研究水封液化气库地下结构设计参数具有重要的实践意义和工程应用价值。烟台万华搬迁工程液化烃地下水封洞库项目是我国第一个大型地下水封液化气洞库,为保证地下水封液化气洞库的安全性、耐久性以及设计的合理性,需要对洞库的地下结构设计参数进行科学研究。论文以烟台万华老厂搬迁工程项目液化烃地下水封洞库的建设为工程背景,运用物理模型模拟试验及数值模拟试验,分别就洞室埋深、高跨比、间距等地下结构参数进行计算分析,为地下水封洞库工程设计提供可靠结构参数,为设计和施工提供理论指导。地下水封液化气库的特点决定了必须要充分依靠和利用建库区的天然地质环境条件,才能保证其自身的安全与稳定。本文在研究地下水封液化气库储气基本理论和洞库物理模拟试验原理的基础上,以烟台万华地下水封液化气库项目为依托,以环氧树脂为材料制作了一批光弹试验模型,运用409-2型光弹仪进行光弹试验。由于原出厂的光弹仪存在一些缺陷,为此,对其进行了升级改造,运用改造后的设备进行洞室模型光弹试验研究,同时采用数值模拟试验的方法对水封液化气库地下结构设计参数进行了研究,通过物理模拟和数值模拟的结果综合分析得出比较合理的结构设计参数值,为该洞库的设计和施工提供依据和参考。论文第二章从液化气的物理特性出发,对地下水封液化气库的基本理论进行了介绍和研究。介绍了液化气库的储存方式,阐述了水封液化气库的储存原理理论,对建设液化气库所必须具备的地质条件进行了论述,并对地下水封液化气库的优越性进行了说明,总结出地下油气储备库具有节约土地、投资省、污染小、保护环境、节省钢材、使用寿命长等特点,建设地下油气储备库是保障国家能源安全的重要措施,是确保安全平稳供气的最有效途径。论文第三章对光弹试验的基本原理进行了研究。光弹性试验方法是一种迅速、准确,经济、有效的应力分析方法,该方法的主要特点是直观性强,可以获取全场信息,通过光弹性试验,可直接观测到模型受力后的应力分布情况,特别是对那些理论计算较为困难、形状及载荷复杂的构件,光弹性试验方法更能显示出其优越性。它能迅速、准确地确定构件的应力集中系数,为改进结构设计,提高结构性能提供试验依据。光弹性试验方法已有一百多年的历史,试验技术也日益成熟和完善。目前。光弹性试验分析方法已广泛应用于航空、造船、机械、石化、水利和土木建筑等部门。论文介绍了平面偏振光、圆偏振光、光的干涉、双折射等光学基本原理,论证了平面应力-光学定律和平面偏振光的光弹效应,对等差线和等倾线的原理进行了详细分析,叙述了白光下的等色线特征和等差线级数的读取方法。在介绍模型相似定理的基础上,分析了模型相似条件。光弹性材料是光弹性应力分析中的一个关键问题。只有良好的材料才能充分显示出光弹性效应,才能据此分析各种力学问题。一个多世纪前,光弹性效应被发现,逐渐形成光弹性原理。由于当时材料不灵敏,模型难以加工,导致光弹试验发展缓慢。二十世纪环氧树脂材料出现以后,逐渐形成了以环氧树脂这种高分子聚合物为基础原料的光弹性材料,大大推动了光弹性法的发展。论文在对地下水封洞库建库原理和物理模拟试验原理进行研究后,第四章以烟台万华液化烃地下水封洞库为依托,采用环氧树脂材料制作了一批光弹试验模型用于物理模拟试验研究。对研究区的工程概况、研究区基本地质条件以及洞库区域地应力情况进行了详细介绍,为洞室物理模型加工制作和后期光弹试验奠定基础。在介绍模洞室模型选取原则的基础上,阐述了烟台万华液化烃地下水封洞库的模型选取方法和采用环氧树脂加工制作洞室模型的过程,共制作出单洞室模型6块,洞室群模型6块,共12块。光弹试验是运用某些特殊透明材料的应力-光学效应,采用光学原理去测量模型的应力场的实验应力分析方法,是一种全场应力测量法,具有直观性强、可靠性高等特点,对分析复杂构件应力场和应力集中现象尤为有利,在土木工程、机械工程等领域应用十分广泛。本次研究物理模拟试验采用了409-2型光弹仪,由于原出厂的409-2型光弹仪主要用于教学演示实验,为了将其运用到洞室研究中,需要对该光弹仪的部分设备进行设计改造。论文第五章介绍了用于试验的409-2型光弹仪及该光弹仪的光路图,提出了实现研究目标设备所存在的缺陷。针对试验设备的缺陷,运用机械设计与制造相关理论对原出厂的409-2型光弹仪的加载部分进行升级改造,改造后的加载系统由加载架和液压传动两部分组成,改造完成后的设备可以进行洞室模型的物理模拟试验。研究地下结构设计参数的方法很多,目前应用较多的有理论分析法、物理模拟法、数值模拟法、工程地质类比法、块体理论法等。物理模拟试验是建立在量纲分析原理和相似原理的基础之上的,一般是通过设计出与原型相似的模型,然后利用该模型来间接的研究原型的一种试验方法。物理模拟试验是人类改造和认识世界的基本方法,随着科学技术和生产力的发展而不断的发展。常用的物理模拟方法主要有模型试验(相似材料法)和光弹试验(光测弹性法)。第六章论文从洞室埋深,洞室高跨比和洞室间距等方面展开了研究,采用光学方法测量具有双折射性能的透明材料制作的受力摸型上各点应力状态,并在模型上施加外荷载,把承载的模型置于偏振光场中,观察与模型上各点应力状态有关的干涉条纹图,按照光弹性原理,确定受力模型各点的主应力差。针对烟台万华洞库,对其地下结构设计参数进行了定量分析。水封液化气库的地下结构设计属于工程力学的范畴,工程力学中的许多问题可用数值分析法划归为大型线性方程组来求解,如微分方程、多未知量等问题。尤其是在近几年的发展中,数值分析法得到了快速的发展,其主要原因是因为计算机的迅速发展推动了数值分析方法的快速发展。针对烟台万华水封液化气库,论文第七章采用数值模拟试验研究水封液化气库的地下结构设计参数,运用FLAC软件分别对地下洞室的埋深、高跨比和洞室间距进行了研究。通过与光弹试验的结论相互比较,综合分析,得出了科学的地下结构设计参数,为该项目的设计与施工提供了依据和参考。本论文主要有以下几个创新点：(1)通过物理模拟试验和数值模拟试验对比研究水封液化气库地下结构设计参数,得出科学可靠的洞室埋深、高跨比、间距等结构设计参数,为地下水封液化气库的结构设计和施工提供理论依据。(2)运用机械设计与制造相关理论对原出厂的409-2型光弹仪的加载部分进行升级改造,改造完成后的设备可以进行洞室模型的物理模拟试验研究。(3)运用光测弹性法对地下洞室的应力状态和变形特性进行分析,为准确获取地下结构设计参数提供理论支撑。更多还原

【Abstract】 Liquefied gas is short for liquefied petroleum gas (LPG), also known as liquid hydrocarbon. It is an inflammable liquid separated from the liquefaction the gaseous hydrocarbon produced in gas-field exploitation, oilfield exploitation, or the process of petroleum refining with removal of dry gas. It is a clean, efficient, low-cost, and high-quality energy. Except as chemical raw material and fuel for power generation, it has been widely used in the field of industry and for civil use. Along with the development of the world industrial progress, various countries are paying more attention to the reserve of petrochemical energy as a national strategic energy, and all kinds of oil and gas storage caverns have been built around the world, with the their types changing gradually from aboveground at first to underground. The underground space has been a widely recognized resource in the industry. On the basis of related planning and research, much study has been conducted on how to make full use of this type of resource to build underground storage cavern. And one of the main utilization patterns is to use existing space or space dug out by hand. Most of large storage caverns are used for oil and gas reserve.The purposes of oil and gas storage include national strategy purpose, commercial storage purpose and personal storage purpose. Strategic reserve of oil and gas refers to a certain quantity of crude oil, refined oil and natural gas possessed and controlled by the central government through means of direct investment or other methods, which is an important means to ensure energy security. In emergency period of war and wide embargo, oil and gas reserves can cope with volatility of international oil market, and cushion or shield its possible impacts on national economy.At present, there are few domestic liquefied gas storage caverns under construction, therefore no similar design or construction experience can be used for reference. We are still in the stage of exploration and test, with many technical problems to be deeply studied. Due to particularity of substances stored, a high requirement is posed on the physical design of underground cavern. During the excavation process and after excavation, initial ground stress inside the cavern will redistribute, changes of internal force and deformation of surrounding rock, especially quantitative analysis on the internal force and deformation of surrounding rock under complex geological conditions and working conditions (such as high water level and dynamic loading, etc.) will help make the right judgment on safety and stability of the surrounding rock and provide theoretical basis for physical design and scientific construction. Therefore, study of physical design parameters of water-sealed liquefied gas storage cavern under specific geological conditions is of important value for engineering application.The underground water-sealed liquefied gas storage cavern project in the relocating project of Yantai Wanhua Group is China’s first large-scale underground water-sealed liquefied gas storage cavern. In order to ensure the security, durability of the cavern and its reasonability of design, scientific research should be conducted on its underground physical design parameters. Based on the construction of underground water-sealed liquefied hydrocarbon cavern in the relocating project of the old Yantai Wanhua Factory, this paper uses numerical simulation test and physical model test to make computational analysis on parameters such as buried depth, depth-span ratio and spacing of the cavern, providing reliable structure parameters for the engineering design of underground water-sealed cavern and theoretical guidance for its design and construction.The characteristics of underground water-sealed liquefied gas storage cavern DECide that its safety and stability can only be ensured with a full dependence and use of the natural geological environmental conditions in cavern area. Based on the research of basic theory of gas storage in the cavern and principle of physical model tests, this paper relies on the Yantai Wanhua underground water-sealed liquefied gas storage cavern project to make a series of photoelastic test models with epoxy resin, and conducts photoelastic tests by Type409-2polariscope. Due to the defects of the factory-fresh polariscope, it has been upgraded before conducting the test. Meanwhile, we’ve also studied the structure parameters of the underground cavern with the method of numerical simulation test. The comprehensive analysis of physical model and numerical simulation results in reasonable structure parameters, which can be used as the basis and reference for the design and construction of the cavern.As a kind of basic chemical raw material and new type fuel, LPG has drew more attention from people. Boasting of its advantages of high calorific value, no dust, no carbon residue and convenient operation and use, the fuel of LPG has been widely used in life field. It is also used to cut metal, bake agricultural products and roast industrial kilns, etc. Chapter Two of this paper introduces storage mode of LPG cavern proceeding from its physical characteristics, illustrates the storage principle of water-sealed LPG cavern, discusses on the necessary geological conditions of constructing an LPG cavern, and illustrates the advantages of underground water-sealed liquid gas storage cavern. With many advantages of land saving, small investment, small pollution, environmental protection, steel saving and long service life, the construction of underground oil and gas storage cavern is an important measure to ensure national energy security, and also the most effective way to ensure safe and stable gas supply.Chapter Three gives a study on the basic principles of photoelastic test. This test is a rapid, accurate, economic and effective stress analysis method, with its main characteristic of strong intuitive. Through the test, you can get whole field information and can directly observe the stress distribution of stressed model, especially for the components with complicated shapes and load and difficult for theoretical calculation, it shows superiority. It can determine the stress concentration factor of component quickly and accurately, which provides experimental basis for improving structure design and structural performance. Photoelastic test has a history of over one hundred years, with its test technology becoming increasingly mature and perfect. At present, this test and analysis method has been widely used in aviation, shipbuilding, machinery, petrochemical, water conservancy and civil construction. This paper introduces basic principles of optics including plane-polarized light, circularly polarized light, interference of light and birefringence, demonstrates theorem of plane stress-optical and photoelastic effect of plane-polarized light, makes a detailed analysis on the principle of isochromatics and isoclinic, and describes the reading method of the features of isochromatics and series of isochromatics in the white light line. It analyzes the similarity of models on the basis of introducing model similarity theorem.Photoelastic materials is the key to photoelastic stress analysis. Only good materials can fully show the photoelastic effect, and therefore work as the basis for analyzing various mechanical problems. More than a century ago, photoelastic effect was found, and gradually evolved into the photoelastic principle. Due to the then insensitive material, it was difficult to process a model, leading to slow development of photoelastic experiment. Since epoxy resin material appeared in the twentieth century, polymer of epoxy resin has gradually become the basic raw material of photoelastic materials, which greatly promotes the development of the photoelastic method. After the research into construction principle of water-sealed cavern and principle physical model test, Chapter Four bases on Yantai Wanhua underground water-sealed liquefied hydrocarbon cavern, makes a series of photoelastic test models with epoxy resin for physical model test. It gives a detailed introduction of the project profile, basic geological conditions of the research area and the stress of cavern area, laying foundation for the processing and manufacturing of cavern physical models and photoelastic experiment in later period. It illustrates the method of selecting the model of Yantai Wanhua and the processing progress of making the model with epoxy resin on the basis of the principle of selecting the cavern model.12pieces of models have been made in total, including6pieces of single cavity and6pieces of multiple cavities.Photoelastic test is an experimental stress analysis method to measure the stress field of model using the stress-optical effect and optical theories of special transparent materials. It is a kind of whole field stress measurement method with features such as strong intuitive and high reliability, which is especially good for analyzing stress field in a complex structure and stress concentration, and is widely used in civil engineering, mechanical engineering and other fields. The study of physical model test uses the Type409-2polariscope. As the factory-fresh polariscope is mainly used in teaching demonstrative experiments, some components of the polariscope need to be transformed in design in order to be applied to the study of cavity. Chapter Five introduces the Type409-2polariscope used in tests and its beam path diagram, and puts forward the defects to realize the target device. Aimed at the defects, the loading system of the factory-fresh Type409-2polariscope has been upgraded and transformed according to related theory of mechanical design and manufacturing. After transforming, it consists of load frame part and hydraulic transmission part, and can be used for cavity model and physical model tests. There are many methods to study underground structure design parameters, of which the currently widely used are theoretical analysis method, physical simulation method, numerical simulation method, engineering geological analogy method, block theory method, etc. Physical simulation test is based on similarity theory and dimensional analysis, using model that is designed similar to its prototype to study the prototype indirectly. Simulation test develops with the development of production and science and technology, and has become one of the basic methods for human to understand and change the world. Commonly used methods of physical simulation include model test (similar material method) and photoelastic test (photoelastic method). In Chapter Six, the paper conducts research into aspects such as cavity depth, cavity depth-span ratio and cavern spacing, etc, uses optical method to measure the stress state of various points on the stressed model made of birefringent transparent material, imposes external force on the model, puts it into polarized light field and then observes fringe patterns related to the stress state. The fringe pattern is associated with stressed model boundary and its internal stress. The main stress difference and stress direction of various points on the model can be determined according to the principle of photoelastic.The underground physical design of water-sealed liquefied gas storage cavern belongs to the category of engineering mechanics, many problems of which can be classified to large-scale linear equations through numerical analysis method and be solved, such as differential equation and multiple unknown variables. Especially in recent years, numerical analysis method enjoys a great boom. The main reason for this is the rapid development of computer pushes forward the development of this method. Chapter Seven uses numerical simulation to study the design parameters of underground structure of water-sealed liquefied gas storage cavern, researches the cavity depth, cavity depth-span ratio and cavern spacing by means of FLAC software, and comes to the scientific design parameters of underground structure after comparison with photoelastic test and comprehensive analysis.There are three innovative points of this paper:(1) Make a comparative study of design parameters of underground structure of water-sealed liquefied gas storage cavern through physical model test and numerical simulation, obtain the scientific and reliable design parameters including cavity depth, cavity depth-span ratio and cavern spacing, and lays a theoretical foundation for physical design and scientific construction of underground water-sealed liquefied gas storage cavern.(2)Aimed at the defects, the loading system of the factory-fresh Type409-2polariscope has been upgraded and transformed according to related theory of mechanical design and manufacturing. After transforming, it can be used for cavity model and physical model tests.(3)Analyze the stress state and deformation characteristics of underground cavern by means of photoelastic test, and provide a theoretical basis for obtaining the accurate underground structure design parameters.更多还原