Risk Evaluation Of Municipal Buried Gas Pipeline

The transmission medium of municipal buried gas pipeline has the character of flammability, explosion and toxicity. The consequence will be very serious when the buried pipeline is failure. So it is quite significant to perform the risk evaluation and ensure safe operation of the municipal buried gas pipeline.In this dissertation, the risk analysis of middle and low pressure pipeline which is used in municipal is performed. The research contents and conclusions were as follows:⑴Based on the comprehensive investigation and a lot of documents, it is defined the main factors of the failure likelihood and consequence.⑵In the risk evaluation of the pipeline, many factors have the character of uncertainty. In order to describe these fuzzy factors exactly, the concept of fuzzy knowledge is introduced and the fuzzy multi-criteria modeling is applied to estimating the risk of the pipeline.⑶The membership function plays very important role in the fuzzy multi-criteria modeling. The choice of membership function can directly affect the result of the assessment. In this dissertation, the membership function applied in the buried pipeline was screened out by testing most of the membership functions.⑷Compared the AHP, the fuzzy-AHP was chosen to calculate the weight of the factors. And the results are coincided with the fact. How to select the coefficient a is difficulty in the fuzzy-AHP. There is different view about the selecting of coefficient a in the present documents. This dissertation has discussed the solution of the coefficient a and obtained a formulation to calculate coefficient a .⑸Base on the mathematical model of fuzzy multi-criteria modeling evaluation method, a software to evaluate the risk grade of the buried pipeline is established by using the VB programming language. This lays the foundation for realizing intelligent risk evaluation of the municipal buried pipeline.⑹Using the neural network tool of MATLAB, BP neural network is applied to...