Optimizing Construction Safety for Segmental Bridges: ANSYS-Based Simulation Assessment of Stress-Strain Behavior under Critical Construction Stage

Mitigating the risk of catastrophic failures of bridges during the construction stage of precast segmental structures remains a critical challenge for civil engineers across the world. Recent incidents have underscored the vulnerability of these complex bridge structures in their incomplete state where the traditional design checks often seemed deficient. This research addresses those gaps by proposing and demonstrating a robust stress and strain based analysis framework specifically targeting the construction phase of the bridge structure. It utilized an advanced 3D Finite Element Analysis with a high simulation tool called ANSYS to develop a highly detailed 40m long and 25m wide six lane full scale model of a representative precast PSC segmental structure. The core focus is to simulate the realistic application of critical construction stage loadings by meticulously tracking the stress and strain distribution patterns, along with their magnitudes throughout the key structural elements (segments, joints, temporary supports, bearings, etc.) at each simulated erection step. The model aims to identify the potential overstress conditions within the M55 concrete grade structure before they are ready to manifest in the real world scenario. The ANSYS based simulations provided unprecedented insights into the stress behaviour of segmental bridge with a maximum principal stress of 25.3 N/mm² observed near the support segments, and the strain behavior evolves during the inherently unstable construction sequence with the value of strain reaching up to 0.0024, revealing the critical zones susceptible to excessive deformation or cracking. The findings demonstrate that strain based monitoring within a sophisticated 3D FEA approach offers a powerful predictive tool for engineers, whereas the conventional stress or displacement limits provide a more sensitive indicator of structural distress under the unique and often underestimated loads present only during construction.