Taking the rear rail foundation of a gravity wharf in Yangjiang as an engineering example，this paper analyzes the common rail foundation structure and puts forward a combined rail beam structure to solve the problem of difficult post-settlement adjustment of the elastic foundation beam during its service period under the action of a heavy-loaded rail crane. Then，the paper calculates and analyzes the foundation beams，steel rails，and sleepers with the finite-element software Midas Civil on the basis of the Winkler hypothesis. The results meet the requirements of engineering application. The design of the combined rail bearer structure is reasonable. Compared with the conventional scheme，it has better comprehensive performance and economic performance. The application research of the proposed combined rail beam structure can serve as a reference for similar projects.