Structural Response of a Two-Span Concrete Bridge with a ۵۰-cm Deck Slab under Combined Concentrated and Distributed Vertical Loads: A Case Study

This study presents a comprehensive numerical assessment of a two-span continuous reinforced concrete bridge subjected to combined vertical point and distributed loading, with emphasis on the structural implications of a ۵۰ cm deck slab. The bridge consists of two equal ۸ m spans and is modeled as a monolithic continuous deck supported by an intermediate pier and two end abutments. The combined loading scenario incorporates a uniformly distributed vertical load representing lane loading, along with a high-intensity concentrated load simulating heavy vehicle wheel or axle forces. This configuration enables simultaneous evaluation of both global bending behavior induced by distributed loads and localized stress amplification associated with point loading. Finite element analysis was performed using Abaqus to capture von Mises stress distributions and vertical displacement (U۲) patterns throughout the deck. The results indicate that the ۵۰ cm slab provides substantial flexural stiffness, leading to controlled mid-span deflections under the distributed component of the load. The concentrated load, however, generates localized peaks in stress that are efficiently moderated by the increased slab thickness and continuity over the intermediate support. Maximum stress responses occur in regions of negative bending moment above the central pier, while maximum deflections appear primarily at mid-span under combined actions. Overall, the findings highlight the significance of slab thickness and structural continuity in improving load distribution, mitigating stress concentrations, and enhancing serviceability performance under realistic mixed loading conditions. This study provides valuable insight into the mechanical behavior of short-span continuous concrete bridges subjected to complex vertical loading patterns and supports informed decision-making in structural design and evaluation.

کلیدواژه ها:

two-span bridge ، concrete bridge ، deck continuity ، finite element analysis