Operation safety evaluation system of ship lock based on extension evaluation and combination weighting method

Ship locks are the most widely used, promising, and important type of navigation structure in the world at present. It is, therefore, crucial to evaluate the operation safety of a ship lock in service. However, the determination of indicator thresholds is challenging. Accordingly, this paper describes the systematic study of the evaluation system of ship lock operation safety. First, the safety accidents of ship locks are counted. According to the rhombic thinking mode (that is, the thinking mode of 'first divergence and then convergence'), with the help of extenics, a multi-indicator hierarchical indicator system including 5 first-class indicators and 47 second-class indicators for the safety evaluation of ship lock operation is established, and 4 safety evaluation grades are classified: normal, deterioration, early warning, and shutdown. The threshold range of each indicator at each grade is determined individually. Second, based on the idea of multi-factor optimization and integration, the process and the matter-element model of ship lock operation safety evaluation based on extension theory are proposed. Then the weight of the safety indicator is determined by the combination weighting method. The evaluation result is consistent with the actual situation.