【作者】 游鹏飞；

【导师】 牟瑞芳；

【作者基本信息】 西南交通大学 ， 交通运输安全工程， 2013， 博士

【摘要】 随着地铁隧道工程的迅速发展,地铁隧道与地面工程相比,存在地质条件复杂、工艺多样化、作业空间受限等特点,给施工风险管理带来较大难度；另外风险管理的理论还不够完善,导致隧道施工过程中的事故(灾害)频发,故风险成为地下工程领域的研究热点问题；为了达到控制风险的目的,首先需要对风险理论进行研究,而风险机理是风险理论的重要内容；只有在掌握风险机理的前提下,才能掌握风险规律,从而有针对性地控制风险；所以,地铁隧道施工风险机理的研究对风险的控制起到关键作用。为了研究机理,掌握风险规律,首先利用系统动力学理论、方法对地铁隧道进行系统分析,进而认识系统内元素在工作方式及各元素在一定环境条件下相互联系、相互作用的关系,分别从力学和能量角度建立系统动力学模型,分别给出因果关系图和流图；根据建立的系统动力学模型,将运用FLAC3D软件模拟的结果嵌入到系统动力学模型中,运用/ensim软件分别从力学和能量角度进行仿真模拟,提高系统动力学模型的精度,进一步拓宽系统动力学的应用范围；为了度量系统风险,运用PHA方法对地铁隧道施工风险评估进行研究,针对PHA方法中风险等级不能定量化确定的缺陷,将模糊集理论和粗糙集理论杂合,建立基于变精度粗糙模糊集的风险评估模型,对PHA中风险等级确定方法进行改进,从而降低风险评估过程的主观性,实现PHA方法的定量化；并利用实例对本文的研究成果的适用性进行验证。全文具体框架如下：(1)对隧道施工风险理论、系统动力学理论与应用、风险模拟、风险评估等国内外研究现状进行整理、归纳,并找出研究现状中存在的问题。(2)针对地铁隧道系统提出问题,并确定系统分析的目的,运用系统动力学的理论、方法对地铁隧道系统进行分析,分析系统的功能、组成及结构；以围岩子系统为重点研究对象,分别从力学和能量角度建立其系统动力学模型,分析其因果关系,给出因果关系图,根据因果关系图画出流图,分别找出围岩子系统的稳定性影响因素和各种变量。(3)将力学数值模拟结果(FLAC3D软件)嵌入到所建立的基于力学的系统动力学模型中进行仿真模拟(Vensim软件)。运用FLAC3D软件进行力学数值模拟,主要研究不同影响因素(围岩条件、埋深、断面形状及尺寸、支护方式、施工工法等)对拱顶沉降量的影响规律,在此基础上建立基于力学的系统动力学模型方程,并检验模型的有效性,再运用Vensim软件进行模型仿真。(4)将能量数值模拟结果(FLAC3D软件)嵌入到所建立的基于能量的系统动力学模型中进行仿真模拟(Vensim软件)。首先对能量风险理论进行分析,主要包括风险与能量的基础理论、能量传递、释放、控制机理等；风险与能量的基础理论分析主要包括风险与能量的关系,地铁隧道施工风险的内涵,风险构成及其要素间的关系,能量意外释放理论的优缺点及应用范围介绍,能量意外释放理论引用的可行性,基于能量原理的风险机制；能量传递机理研究主要包括应变能传递过程的描述,能量的传递机理及传递的可能性分析；能量释放机理研究主要包括应变能的释放条件、释放机理及释放可能性分析；结合应力-应变曲线分析系统能量控制机制。运用FLAC3D软件进行能量数值模拟,主要研究不同影响因素(不同围岩条件、埋深、跨度等)对应变能积聚和释放的影响规律,在此基础上,建立基于能量的系统动力学模型方程,并检验模型的有效性,再运用Vensim软件进行模型仿真。(5)运用PHA方法对地铁隧道施工风险评估进行研究,在PHA风险等级划分的基础上,将模糊集理论和粗糙集理论杂合,采用文中所建立的基于变精度粗糙模糊集的风险评估模型确定系统风险等级。在基于变精度粗糙模糊集的风险评估模型中,将风险分为固有风险和附加风险分别进行研究；运用标准规范确定固有风险指标的等级划分标准,运用力学风险模拟分析的结果确定附加风险指标等级划分标准,运用基于变精度粗糙模糊集的风险评估模型对样本进行风险评估研究,确定风险等级,其中根据实测值运用粗糙集理论确定指标权重,降低了主观因素对评价结果的影响,使评估结果更具客观、准确。(6)以成都地铁2号线一期工程通惠门停车线暗挖区间隧道为例,运用PHA方法对其进行风险评估,验证PHA方法和基于变精度粗糙模糊集的风险评估模型的适用性。更多还原

【Abstract】 With the rapid development of subway tunnel engineering, there are some characteristics in subway tunnel engineering compared with the ground engineering, such as complex geological conditions, technological diversification, confined space operations and so on, which make the risk management of construction more difficult. In addition, risk management theory is not yet perfect that leads to the tunnel construction accidents (disasters) occur frequently, so the risk of subway tunnel construction becomes the hot issue in the field of underground engineering. In order to control risk, the research on the risk theory becomes the primary task and the risk mechanism is the important content of risk theory, only when the risk mechanism is grasped, can the risk rules be grasped, so that to control the risk. Therefore, study on the risk mechanism of subway tunnel construction plays a key role in risk control.In order to study the risk mechanism and master the risk rule. First the idea of system dynamics is used to do the systemic analyze of the system, so as to understand the way of working of the elements in the subway tunnel system and the interactive relationship between the various elements under certain environmental conditions, to establish system dynamics model from the angle of mechanics and energy, to draw causal loop diagram and flow chart. According to the system dynamics model established, results of FLAC3D software simulation are embedded the system dynamics model, the Vensim software is used to simulate respectively from the angle of mechanics and energy, which can improve the accuracy of system dynamics model, to further expand the application range of the system dynamics. In order to measure the system risk, PHA method is used to evaluate the risk of subway tunnel construction, aiming at the defect which cannot ascertain risk level of PHA method quantitatively, combined the fuzzy set theory with rough set theory to establish risk assessment model based on variable precision rough fuzzy set to improve the method of risk classification of PHA, so that to reduce the subjectivity of the risk assessment process to realize quantitative PHA method. The research results of this dissertation are verified by practical examples. The concrete framework of the full dissertation is as follows:(1) The research status of tunnel construction risk theory, theory and application of system dynamics, risk simulation, risk assessment in and abroad are collated and summarized, and find out the existing problems.(2) In the analysis of subway tunnel system, in the first place, put forward the question of the subway tunnel system and confirm the purpose of the system analysis. The theory and method of system dynamics are used to analyse and study the subway tunnel system, the function and composition of the system. Based on the surrounding rock system as a key research object, the system dynamics models are established from the angle of mechanics and energy to analyze its causal relationship, and show the causal relationship graph to draw a flow chart according to it, finally find out the main influencing factors and various variables of the system stability.(3) The mechanics simulation result (FLAC3D software) is embedded into the system dynamics model based on mechanics, then the model is simulated (Vensim software). FLAC3D simulation software is used to simulate the influence law between different influential factors (surrounding rock condition, buried depth, section shape and size, support, construction and so on) and the vault settlement. On this basis, the equations of system dynamics model based on mechanics are estabished. The validity of the model will be tested. Finally, the model will be simulated by Vensim software.(4) The energy simulation result (FLAC3D software) is embedded into the system dynamics model based on energy, then the model is simulated (Vensim software).First of all, this paper analyzes energy risk theory, including risk and energy theory, the energy transfer, release, control mechanism. Basic theory analysis of risk and energy including relationship between risk and energy, the connotation of the subway tunnel construction risk, the relationship between risk constitution and key elements of risk, the advantages and disadvantages and the scope of application of the energy accidental release thory, the feasibility of the implementation of the energy accidental release theory, the risk mechanism based on energy principle. In the study of energy transfer mechanism, strain energy transfer process should be described and the energy transfer mechanism and the probability of strain energy transfer should be analyzed. In the study of energy release mechanism, the release conditions, release characteristics, release mechanism and possibility of strain energy should be analyzed. The control mechanism of strain energy should be analyzed by combining with the stress-strain curve.FLAC3D simulation software is used to simulate the influence law between different influential factors (surrounding rock condition, buried depth, section shape and size) and characteristic of accumulation and release of energy. On this basis, the equations of system dynamics model based on energy are estabished. The validity of the model will be tested. Finally, the model will be simulated by Vensim software.(5) PHA method is used to assess the risk of subway tunnel construction. Based on risk classification of PHA, combined the fuzzy set theory with rough set theory to establish risk assessment model based on variable precision rough fuzzy set to improve the method of risk classification of PHA. In the model establised, the risk is divided into the inherent risk and additional risk. The classification standard of inherent risk indexes are confirmed by using standard specification. The classification standards of additional risk indexes are confirmed by using the mechanics simulation results. Using the risk assessment model based on variable precision rough fuzzy set to study risk assessment of the sample, and to determine the risk level, the index weight is defined according to the measured values by using rough set theory, which can reduce the subjective influence to the assessment results, so as to enable the assessment results more objective, accurate.(6) Take the Tonghui door stop line tunnel of Chengdu Subway Line2project as an example, using the PHA method to assess the risk of it to verify the applicability of PHA method and the risk assessment model based on variable precision rough fuzzy set.更多还原