The focus of this study is the transition pier of the main approach bridge in a newly constructed project in Chengdu. It begins by introducing the configuration strategy for the prestressed tendon layout. A comparative analysis of sectional stresses is then conducted under prestress loading conditions and at the completed bridge stage, using both spatial frame models and spatial solid models. Special emphasis is placed on investigating the torsional shear stress induced by structural and loading asymmetry in the L-shaped cap beam. The results show that the spatial frame models could meet practical engineering requirements. These findings provide valuable references for the design analysis of similar engineering projects.