Study On Reliability Assessment Of Interface In Bridge-tunnel Connection Section Of High-speed Railway

With the continuous advancement of China’s railway construction,the high-speed railway network in the western mountainous areas is becoming more and more perfect,and the scientific research work on high-speed railways has also become a hot spot in the field of transportation in recent years.The phenomenon of bridge-tunnel connection engineering has always been concerned by experts in the industry,and the scientific boundaries have been continuously expanded.In recent years,in-depth related research on railways represented by interfaces has also gradually emerged.Among them,the paper takes the high-speed railway bridge-tunnel connection section as the research background;the high-speed railway engineering interface as the research object;reliability evaluation as the research purpose to carry out a series of research work.Based on system engineering theory and reliability engineering theory,this paper constructs a research framework for interface reliability evaluation of high-speed railway bridge-tunnel connection section.The reliability evaluation framework consists of interface correlation analysis,interface failure analysis and interface reliability evaluation it is composed of three research modules.The relationship analysis module includes three steps:dismantling the system,identifying interfaces and quantifying the relationship;the fault analysis module mainly involves the analysis of interface failure causes and failure evolution;the reliability evaluation module compares Selection,establishment of evaluation model,development of reliability evaluation and proposal of supportive strategy are realized.The dissertation puts forward the system decomposition process of bridge-tunnel connecting section of high-speed railway,and obtains the decomposition structure with the result of railway specialty according to the decomposition principle and basis;establishes the interface identification process based on the system structural model and combined with the design structure matrix expression form.A list of engineering interfaces of bridge-tunnel connecting sections including descriptions of interface associations and precautions was sorted out,secondary interface identification was carried out for the potential associations of discovered interfaces,the visualized engineering interface associations and professional hierarchical networks were obtained based on complex network theory.The quantification method of the interface association relationship of the high-speed railway bridge-tunnel connecting section including the qualitative description of the interface association state and the analysis of the information entropy of the interface set is given,the classification of the engineering interface is completed according to the quantification results.The paper explores the failure mode of the engineering interface of the bridge-tunnel connecting section of the high-speed railway;sorts out the engineering structure characteristics of the bridge-tunnel connecting section,the management characteristics of the high-speed railway interface itself common faults and diseases,finds that the interface of the bridge-tunnel connecting section of the high-speed railway is caused.Fault factors include external environment disturbance and internal fault propagation;the research idea of information entropy change for internal fault propagation of the system is proposed;the noncooperative game is used as the skeleton,the fault information entropy becomes the context and the basic unit of interface fault is the fault propagation simulation model of the elements;the conclusion that difference in the degree of correlation between the interfaces leads to the difference in the fault performance of the interfaces in the process of fault propagation.This paper builds a reliability evaluation model for the interface of the bridge-tunnel connecting section of the high-speed railway;compares the applicable scenarios and advantages and disadvantages of existing reliability modeling methods from qualitative and quantitative perspectives,discusses the role of Bayesian networks in uncertainties.The reason why the accuracy of analysis and calculation reasoning is suitable for engineering interface reliability assessment;gives the Bayesian network reliability assessment modeling steps,demonstrates the feasibility of constructing Bayesian network starting from causality,introduces engineering interface faults Probability distribution function,based on the minimum cut set method and the chain rule to optimize the scale and computational reasoning efficiency of the Bayesian network;obtained the independent fault probability estimation results of the engineering interface and the quantitative data for judging the reliability of the system;proposed a targeted the periodic maintenance strategy and integrated maintenance strategy of the engineering interface and the feasibility of the two strategies are respectively demonstrated through the fault simulation situation after the periodic maintenance strategy is introduced in the interface and the Bayesian network information update capability.The main innovation of the thesis research is to break through the previous research ideas of high-speed railway interface limited to the design stage or construction stage,expand the research perspective to the longer-term operation and maintenance stage of the railway and adopt a systematic research framework to carry out high-speed railway bridge-tunnel research.Research on reliability of interface of connecting section.The obtained research results can provide a reference basis for the formulation of high-speed railway interface maintenance system,interface reliability improvement,line operation safety assessment of bridge-tunnel connecting section,etc.,and can also provide reference for planning the safety and reliability of high-speed railway interface design.Forecast provides technical support.