MANAGING AND MAINTAINING STORMWATER DRAINAGE SYSTEM OF THE REVITALISED GAZELA BRIDGE OVER THE SAVA RIVER IN BELGRADE

Abstract

The paper presents the design of the drainage system of the Gazela Bridge over the Sava River in Belgrade during its reconstruction and subsequent experiences related to the assessment of the system’s efficiency. The bridge was originally built without a drainage system with direct discharge of polluted runoff into the river and the surrounding terrain, which posed a risk to the structure and the quality of surface and groundwater in the protected water supply zone. The reconstruction of the bridge also included the construction of a system for efficient water collection and conveyance, combined with treatment, retention and controlled infiltration. The retention-infiltration facility including the first flush treatment enables partial reuse of stormwater for irrigation and watering, indirectly recharging groundwater. On the other hand, dynamic testing of the bridge structure under load and subsequent deformation modelling showed that bridge deflections can significantly affect the efficiency of drainage by changing the pipeline slope and thus the flow conditions, with an increased risk of sediment deposition in the pipes. A bridge inspection revealed degradation of the drainage system, highlighting the importance of maintenance to ensure the functionality of the system, especially to prevent clogging of culverts and pipes. The paper highlights the need for an integrated design approach that considers traffic, hydraulic, structural and environmental aspects, while the presented results indicate a practical path for sustainable stormwater management on bridges, especially in sensitive urban and hydrogeological environments.