Abstract:The structures in anchorage zone of built-in steel anchor box pylon in cable-stayed bridges is complex. Although the traditional 3D solid + shell element model offers high precision, the modeling is complex and it is difficult to directly extract the internal forces of the pylon wall cross-section for reinforcement design. Taking a single-pylon cable-stayed bridge as the engineering background, a simplified 2D calculation model with beam + shell elements is proposed. By comparing with a refined 3D model, the reliability of the simplified model in calculating internal forces of the pylon wall is verified. A systematic analysis is conducted on the influences of connection methods, structural parameters, concrete cracking, and concrete shrinkage and creep on the force of the anchorage zone. The research result indicates that using elastic connections to simulate the stiffness of welding studs more realistically reflects the structural force compared to the fully fixed model. The internal force error between the simplified and refined models is controlled within 15%. The larger the ratio of the longitudinal and transverse dimensions of the anchorage zone of pylon, the higher the proportion of the horizontal cable force borne by the concrete pylon wall. The concrete cracking, shrinkage and creep have a significant impact on the force of the pylon wall.
