【作者】 徐青；

【导师】 赵云胜；

【作者基本信息】 中国地质大学 ， 安全科学与工程， 2017， 博士

【摘要】 近年来,武汉城市地铁建设进入了飞速发展的黄金时期,全市共规划26条地铁线路,目前在建地铁线路11条,已建5条,且大部分的地铁线路都穿越人员密集区、交通枢纽区、复杂地层区等路段,与此同时,安全生产事故不断,其中深基坑涌水事故尤为突出,若不及时的进行有效控制,其所带来的事故后果不可估量,严重时更会导致基坑的垮塌,造成周边构筑物破坏、人员伤亡等次生灾害。论文以武汉地铁车站深基坑开挖过程中的涌水风险分析与控制为研究主题具有十分重要的指导意义。首先,本文对比分析了当前地铁深基坑施工的特点,传统的风险分析方法难以抓住涌水事故的时间序列特征,而动态故障树的风险分析方法对具有明显时间序列的事件处理具有独特的优势,论文由此引入动态故障树理论,以武汉唐家墩地铁站深基坑为例构建了基坑涌水事故动态故障树模型。而动态故障树的基本事件概率多具有不确定性,常用的贝叶斯、马可夫链等方法均无法快速有效的对动态故障树进行分析,而蒙特卡洛抽样方法可以快速的对动态故障树进行计算处理,因此论文引入蒙特卡洛的方法对涌水事故发生的可能性进行了模拟研究,利用动态故障树和蒙特卡洛结合的方法,深入分析了基坑涌水系统的复杂性,有效的分析了顶事件受基本事件不确定影响作用的变化规律,为后期预防涌水事故提供了可靠的依据。其次,本文为有效的探寻涌水事故的后果影响,以涌水事故对基坑周边环境的影响作用模式以及基坑渗流理论为基础,运用FLAC3D模拟的方法对比研究了正常开挖和涌水事故发生后两种不同状态下的基坑周边变形情况,结合基坑周边的实际环境特点分析了涌水事故的影响范围,并运用GEO Studio软件模拟的方法研究了涌水与渗流场改变之间的相对关系,得出了涌水事故条件下的涌水速度,为事故应急救援提供了决策支持,具有重大的理论和现实意义。再次,本文在分析深基坑涌水造成的事故影响的基础上,针对深基坑工程传统监测预警的低效性和滞后性等问题,结合大量收集的监测资料,利用时间序列ARMA模型分析序列数据前后的相关性,总结武汉地区以回填土为地铁施工地质条件的涌水事故特点,并运用ARMA模型对武汉地铁深基坑发生涌水事故前后的变形监测数据进行分析。通过研究数据ARMA模型的模式波动情况对深基坑涌水风险进行预报预警,同时根据不同监测单点的数据进行综合模型分析,达到全面感知基坑涌水事故风险的目的,相对于常规的监测与传统的数据分析来实现基坑涌水风险的预测预警,优化后的监测预警更加高效、敏感。最后,本文以优化应急救援为主线,针对深基坑涌水应急的特点进行深入的分析与总结,囊括出目前深基坑涌水事故应急救援在时间、空间、物资、人力、成本等方面存在的应急短板,构建符合我国现状的深基坑涌水事故应急过程网络图,并以此为基础构建基于多目标的涌水事故应急约束模型,从而有效的解决应急过程中的约束难题;另外对涌水应急过程中的物资重要性进行研究,通过构建应急物资ISM模型,确定涌水应急系统中物资的层级关系及其相对重要性,有效的指导应急物资的储备与调运;最后,建立涌水应急物资的调度联络网络,并对其进行优化研究,以此提高地铁深基坑涌水事故应急救援的效率。更多还原

【Abstract】 In recent years,the urban subway construction in Wuhan has entered the golden age of rapid development.At present,the city has maked an urban panning of 26 metro lines,with 11 lines under construction and 5 lines which have builded.Most of the subway lines are through the high populated areas,transportation hub areas,Complex formation areas,etc.At the same time,the production safety accidents happen frequently,especially the water burst in deep foundation pit water accident.Without timely effective control measures,the accidents will bring serious consequences which maybe leading to collapse of foundation pit in severe cases,and the collapse will result to the damage of surrounding structures,casualties and other secondary disasters.This paper takes risk analysis and control of water burst in the deep foundation pit of Wuhan subway during the process of excavation ai the object of study,which has crucial instructive meaning.First,the risk analyzes method of dynamic fault tree has its unique advantage of handling the event with obvious time series over the traditional risk analysis methods.So this paper introduces the theory of dynamic fault tree and builds the dynamic fault tree model taking the water burst in foundation pit of Tangjiadun subway station in Wuhan as an example.The basic event probability of dynamic fault tree is uncertain.Bayesian,Markov chains,and other methods are unable to analyzes the dynamic fault tree quickly and efficiently,while quickly and monte carlo sampling method to calculate the dynamic fault tree,while the Monte carlo sampling method can make it.Therefore,the paper makes a simulation study about the possibility of water burst accident by citing the Monte Carlo sampling method,does deep analysis on the complexity of foundation pit water burst system and effectively analyzes the change rules of uncertain effect which top events affected by elementary events,providing a reliable basis to prevention of water burst in later period.Secondly,to effectively seek the consequences of the accident,this paper makes a comparative study on the deformation around the foundation pit uder two different state,normal excavation process and water burst state,using FLAC3 D and based on the impact model the surrounding environment affected by water burst accident and seepage theory of foundation pit.The paper also analyzes the sphere of influence of water burst combined with the actual environment around the foundation pit,and studies relative relationship between water burst and seepage field changes by GEO Studio.The study obtains the gushing water speed under the condition of water burst accident,which has important theoretical and practical significance to provide decision support to the accident emergency rescue.Thirdly,based on the analysis of the accident caused by water infiltration in deep foundation pit,aiming at the low efficiency and hysteresis of traditional monitoring and early warning of deep foundation pit engineering,combined with a large number of monitoring data,this paper uses the ARMA model to analyze the correlation of sequence data.At the same time,this paper summarizes the characteristics of gushing water accident in Wuhan area which is based on the geological condition of the backfill,and analyzes the deformation monitoring data of the gushing water accident before and after in the deep foundation pit of Wuhan Metro by using ARMA model.And this paper tries to predict and warn the risk of deep foundation pit gushing by studying the pattern fluctuation of the ARMA model,and analyzes the data of different monitoring points comprehensively to achieve the purpose of fully sensing the risk of water gushing.Compared with the conventional monitoring and traditional data analysis to achieve the prediction and early warning of the risk of water gushing,the optimized monitoring and early warning is more efficient and sensitive.Finally,this paper takes the optimization of emergency rescue as the main line,analyzes and summarizes the characteristics of emergency of deep foundation pit gushing,and includes short board of water gushing emergency in the space,time,material,manpower,cost,etc.Constructing the network diagram of the emergency response process of the deep foundation pit water gushing in accordance with the present situation of our country,and on the basis of the above,the paper constructs an emergency constraint model of water gushing accident based on multiple objective,which can effectively solve the constraint problem in the emergency process.In addition,the importance of material in the process of water gushing emergency is studied.By constructing the ISM model of emergency materials,it is determined that the hierarchical relationship of material and its relative importance in the emergency system of water gushing,and it effectively guide the storage and distribution of emergency supplies.Furthermore,the paper constructs the emergency dispatch network of water gushing,through the construction of the emergency dispatch network of water gushing emergency materials,and to optimize it,so as to improve the efficiency of emergency rescue of deep foundation pit.更多还原