Abstract: The seismic safety of inland river wharves in high-intensity seismic areas is directly related to the reliability, service continuity, and long-term resilience of regional transportation infrastructure. This issue is particularly critical in reservoir areas and mountainous river valleys, where complex topography, heterogeneous geological conditions, and strong tectonic activity may jointly amplify seismic effects. Taking the high-piled frame freight wharf in the Gele Central Operation Area of Dongchuan Port within the Baihetan Reservoir as the research object, this study investigates the seismic response, performance evolution, and fragility characteristics of a typical inland river wharf located in a high-seismic-intensity area. A refined three-dimensional finite element model is established in OpenSees, in which the nonlinear behavior of reinforced concrete members is represented using fiber beam-column elements, while the interaction among the soil, piles, and superstructure is explicitly considered. The numerical model incorporates key factors affecting seismic performance, including the material nonlinearity of concrete and reinforcing steel, contact behavior at structural joints, pile-soil interaction through nonlinear spring elements, second-order gravity effects, soil damping and inertial effects, and hydrodynamic added mass. In this way, the model is capable of capturing the progressive development of stiffness degradation, deformation accumulation, and local damage under increasing seismic intensity. Based on the seismic safety evaluation results for the engineering site, ground motions compatible with local site conditions are generated using the Endurance Time Method (ETM). Unlike conventional incremental dynamic analysis, which requires repeated nonlinear analyses under multiple scaled earthquake records, the ETM introduces artificial acceleration time histories whose intensity increases gradually with time, thereby allowing the continuous evolution of structural response to be captured within a limited number of analyses. The target design spectrum adopted in this study is derived from the site-specific seismic parameters of the Dongchuan Port project, and three sets of three-component endurance time ground motions are generated to represent horizontal and vertical seismic excitations. This procedure ensures that the input motions are not only spectrally compatible with the design basis of the project but also suitable for evaluating the progressive deterioration of the wharf structure from minor to strong earthquake levels. According to the structural configuration and load-transfer characteristics of the high-piled frame wharf, together with relevant Chinese and international seismic design standards, the maximum inter-story drift ratio of the upper frame structure and the maximum displacement at the pile head are selected as the key engineering demand parameters. On this basis, a multi-level seismic performance evaluation system is established. Four performance levels are defined, namely operational, repairable, life safety, and collapse prevention, and corresponding quantitative limit values are specified for the selected response indices. The performance criteria for the pile foundation are further supported by concrete and reinforcing-steel strain thresholds at critical sections, so that both global deformation and local material damage can be assessed within a unified framework. The resulting evaluation system provides a rational basis for linking structural response, damage state, and design objectives under earthquakes of different intensity levels. Nonlinear dynamic time-history analyses are then performed under the generated ETM ground motions. The results indicate that the Endurance Time Method can effectively reveal the dynamic response characteristics and damage development process of the inland high-piled frame freight wharf under increasing seismic intensity. With increasing earthquake intensity, the moment-curvature hysteresis curves of representative pile sections become progressively fuller, showing obvious plastic development and stable energy dissipation capacity. Both the maximum inter-story drift ratio of the upper frame and the maximum pile-head displacement exhibit clear nonlinear relationships with peak ground acceleration, reflecting the importance of considering material and geometric nonlinearity in the seismic analysis of such structures. The response concentration at the lower part of the frame and at critical pile sections also confirms that these locations govern the seismic performance of the entire wharf system. To quantify structural vulnerability in probabilistic terms, fragility curves are developed for different performance levels by statistically relating the seismic demand to peak ground acceleration. The resulting curves are used to evaluate the probabilities of exceeding each limit state under frequent, design-basis, and rare earthquakes. The analysis shows that under frequent earthquakes, both the upper structure and the pile foundation remain essentially intact, with only a very low probability of slight damage. Under design-basis earthquakes, the upper frame may experience limited and repairable damage, whereas the pile foundation largely remains in a safe working state. Under rare earthquakes, the upper structure enters a more pronounced nonlinear stage, but severe failure remains unlikely, while the pile foundation still shows relatively low probabilities of moderate and severe damage. These results indicate that the studied wharf satisfies the seismic fortification objective of "no damage under minor earthquakes, repairable damage under moderate earthquakes, and no collapse under major earthquakes." In summary, the proposed combination of refined soil-pile-structure interaction modeling, ETM-based nonlinear dynamic analysis, performance-level evaluation, and fragility assessment provides an efficient and practical methodology for the seismic analysis of inland river wharves in high-seismic-intensity areas. The research findings not only verify the good seismic performance of the Dongchuan Port wharf but also provide valuable technical support and methodological reference for the seismic design, safety evaluation, and resilience enhancement of similar pile-supported inland port structures.