Research On Operational Safety Risk Assessment Method Of Urban Underground Pipe Corridor Based On Inherent Risk And Accident Risk

The urban underground comprehensive pipe corridor is a high-level system with complex composition,covering multiple disciplines and fields.With its efficient service efficiency and reliable service capabilities,it has become an important part of modern urban public services.However,although the construction of the city’s comprehensive underground pipe corridor can be traced back to nearly two centuries ago,due to the numerous unknowns and the research depth that is difficult to predict and evaluate,the relevant researches leading to the safety guarantee of the city’s comprehensive pipe corridors are still imperfect,and there is no clear,scientific,comprehensive and systematic theoretical method.Scientific and accurate risk assessment is an urgent problem that must be faced and urgently resolved in the process of urban comprehensive pipeline corridor construction and system operation.This paper analyzes and compares the risk evaluation methods,selects the evaluation method that meets the applicability of the comprehensive risk evaluation method of the underground pipeline corridor,and constructs a more comprehensive comprehensive urban underground pipeline corridor comprehensive risk evaluation model from the three levels of risk identification,risk analysis,and risk evaluation.The model is divided into two parts,namely inherent risk assessment model and accident risk assessment model.The establishment of the inherent risk model is to identify the risk factors of the underground pipe corridor operating system,and to summarize the safe operation risks of the underground pipe corridor as logically as possible,comprehensively and meticulously.Research on risk identification focuses on the idea of analytic hierarchy process based on multi-objective decision-making,combined with existing data such as similar structure risk analysis,full-life risk analysis,operation and maintenance risk analysis,etc.to identify underground pipe corridor risk.Based on the principle of non-repetitive and non-crossing affiliation of various risk indicators,the multi-angle and wide-range layered structure of urban underground comprehensive pipe corridor operation risks is constructed: 5 inherent risks,18 risk sources,and 58 risk factor indicator systems.After the index system is determined,a risk analysis of inherent risks is performed,and the risk of each risk factor index is expressed by weight.The risk analysis is completed in three parts.The first part is the risk source that belongs to the same inherent risk,and the judgment comparison matrix is constructed through the layer-by-layer comparative analysis to calculate the weight;The second part seeks the weight of risk factors.From the three perspectives of vulnerability,sensitivity and uncertainty,the scoring dimension of evaluation indicators is refined and assigned,which greatly meets the fuzzy characteristics of risk indicators.Solve the gray correlation degree of each risk factor under the same inherent risk and normalize them;The third part is the comprehensive evaluation.The weight of the inherent risk is obtained by the weight of the risk source and the gray correlation of the risk factor,and the result is balanced by the gray correlation to weaken the subjective influence of a few experts when the judgment on the standard is highly consistent.The risk accident assessment model is the risk evaluation of risk accidents caused by several risk factors.Based on the mechanism analysis of the four basic risk accidents,the first-level accident chain(single accident)and the second-level accident are established.The chain(father-son),three-level accident chain(father-son-child)and Bayesian network directed acyclic graph of the consequences of risk accidents,the combined weights of the hierarchical analysis structure are used to express the possibility of risk accidents.By solving the joint probability distribution of the accident chain,the main cause of the accident escalation is judged.Taking the Jimingshan Road Comprehensive Pipe Corridor Project in the High-tech Zone of Hefei City as an example,a quantitative evaluation was conducted to verify the rationality and feasibility of the evaluation method constructed in this paper.The results show that the types of pipelines entering corridors among the inherent risks of urban underground comprehensive pipeline corridors are the most influential risk sources;leakage accidents are the basic events of floods and fires,and the possibility of triggering accident chains is the largest;fire accidents are the most important type of risk accidents,with the greatest impact on time and space.Strengthening the prevention and monitoring of fire incidents,paying attention to the maintenance and inspection of the waterproof measures of corridor structure,ensuring the local monitoring and maintenance of pipeline valves,joints and other parts,and ensuring the accurate and reliable operation of monitoring and alarm equipment have a great impact on the regular risk assessment and management.Figure [11] table [28] reference [70]...