###### Abstract  
Based on the nonlinear damage theory, this paper aims to explore the fatigue performance of steel bridge deck asphalt pavement under multistage fatigue load. Manson-Halford cumulative damage model and the modified model were introduced to describe loading sequence effects, and interactions between multiple loads were represented in stress ratio. The fatigue life prediction method of steel bridge deck asphalt pavement was put forward, considering loading sequence effects and load interactions. The fatigue design of steel bridge deck asphalt pavement was investigated with the fatigue life prediction model. The effects of different load levels and loading sequence on the fatigue design parameters stress ratio of steel bridge deck asphalt pavement were studied. The design results were compared with experimental results, and the prediction results were based on traditional Miner's theory. The analysis results showed that the fatigue life prediction method based on the nonlinear cumulative damage theory can effectively design and analyze the fatigue characteristics of asphalt pavement of steel bridge deck with high accuracy and reliability. The fatigue life prediction model of steel bridge deck asphalt pavement can well reflect loading sequence effects and load interactions. In addition, the design model has relatively few parameters; therefore, it can be applied to practical engineering design. steel bridge deck asphalt pavement; fatigue performance estimation; stress ratio; Manson-Halford model; loading sequence effect  
8 May 202114 June 202118 June 2  
of steel bridge deck asphalt pavement effectively, obtain the fatigue stress parameters for analysis reasonably, and calculate the actual stress ratio are the primary tasks for fatigue design of steel bridge deck asphalt pavement structure [12]. In the design and analysis of fatigue life of steel bridge deck asphalt pavement, the method based on the S-N curve, combined with fatigue cumulative damage theory, is one of the two main categories of methods currently applied [13]. As for its prediction, the analysis of fatigue damage accumulation is one of the key problems. Palmgren-Miner's linear cumulative damage theory (Miner's rule) is used in most fatigue assessment systems for steel bridge deck asphalt pavement nowadays, which is relatively simple in calculation and has been widely used in engineering [14]. However, [PERSON]'s rules have ignored the loading sequence of cyclic loads and the influence between loads, which cannot guarantee the accuracy of fatigue life prediction, which often cannot meet the engineering requirements [15]. A large number of test data and engineering practices have also shown that loading sequence effects and load interaction effects cannot be ignored in the fatigue life prediction [16; 17]. At present, most studies on fatigue characteristics of steel bridge deck asphalt pavement have ignored the loading sequence of cyclic loads and the influence between loads [18; 19; 20]. Therefore, when the method design based on the S-N curve combined with fatigue cumulative damage theory is adopted, it is necessary to conduct a deeper study on the fatigue cumulative damage law, which is an important topic, and to try to adopt the nonlinear cumulative damage theory or improve the [PERSON]'s rules to make up for its deficiencies [21; 22]. Based on the nonlinear cumulative damage theory, there are many theoretical models for fatigue design analysis, which mainly include nonlinear damage accumulation theory based on damage curve method, nonlinear damage accumulation theory based on continuous damage mechanics, nonlinear damage accumulation theory based on energy method, nonlinear damage accumulation theory based on physical property degradation, nonlinear damage accumulation theory considering load interactions, etc. [23]. [PERSON] and [PERSON] have presented the relationship between crack length and cycle ratio, as well as the calculation method of parameters, so as to establish a relatively complete Manson-Halford model [24; 25].