ABSTRACT

The features of the methodology for bridge management in Serbia are reviewed in the light of flooding event in May 2014. The main goals are to determine whether the damages to the road network could have been anticipated and recommend the principal steps for improving current procedures for management of bridges exposed to flooding hazard.

The data on special field inspection from 87 bridges affected in the flood have been reviewed and bridges are sorted into two groups according to the observed damage (Table 1). Based on the methodology for bridge management in Serbia, a new partial rating score for the general assessment of a threat of flood damage is evaluated for the affected bridges. It is concluded that the occurred damages could not have been reliably anticipated based just on the information in the Serbian bridge database. The methodology needs to include risk-based assessments to consider local scour as the most common cause of bridge failures in flooding events. Damages at bridge sites.

Group I (32 bridges)

Group II (55 bridges)

Damage type

Sites

Damage type

Sites

Access roads damaged

16

Embankments affected

12

Damage to structure

8

Infill/River bed affected

4

Collapse

4

Resurvey necessary

32

Overtopping

4

No damage

7

The bridge vulnerability is suggested as a convenient quantitative indicator which identifies the most endangered bridges that are to be inspected in more detail. Here, the essential ingredient is the conditional probability of a bridge failure. The approach for its evaluation, for reinforced concrete bridges with shallow foundations exposed to local scour, was recently presented in Tanasic & Hajdin (2015). It takes into account the resistance of a bridge structure and supporting soil by analysis of a combined soil-bridge failure mechanism (Figure 1). The approach is envisioned to be applied on a network level thus provide a basis for vulnerability maps with respect to a flooding hazard. Possible combined soil-bridge failure mechanism. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig110_1.tif"/>

For the maps development, besides data from the bridge database, there is a need to define the most probable failure scenarios, conduct special & regular field inspections and elaborate damage catalogues. Also, traffic simulations are necessary to reliably estimate indirect consequences for a relevant part of a network, as presented in Tanasic et al. (2013). The maps are going to aid in assigning of the appropriate quality control plans to vulnerable bridges. The background tasks and suggestions for an update of the plans for endangered bridges are discussed.

The vulnerability maps will give realistic information on the expected consequences of extreme flooding events and related local scour thus support data driven decisions in the future bridge management systems. The topic of further research is going to consider the adequate evaluation procedures and equipment for conducting quality control plans for the entire Serbian road network.