Titel_SS06

 Accidents to ships resulting in offshore spills of more than 500 tonnes (TANKER),
Betrand and Escoffier (1987).

Identification of Exposures and Event Scenarios in Civil Engineering Applications

In principle all the previously described approaches may be applied for the identification of
exposures, events and scenarios in civil engineering applications despite the fact that these
were developed originally for other application areas. However, it is always good to have a
certain overview and understanding of the problem framework underlying the engineering
system or activity of consideration and therefore a discussion will be given to the specifics of
hazards and their identification in the area of civil engineering.

The problem setting may be illustrated by consideration of a project involving a concrete
structure. For this example the special concern is the performance of the concrete structure
and in Figure 4.14 the various factors influencing the performance are identified.

It is seen from Figure 4.14 that the life of a structure in fact is already initiated in the
contracting phase and is influenced by a number of factors throughout the design phase, the
construction phase, the operational phase until it is finally taken out of use and
decommissioned. These factors in turn may have adverse implications on the safety of
personnel, the environment and the service life costs associated with the structure. The
circumstances under which these adverse implications occur are the hazards or the hazard
scenarios.

Safety

ContractingPhase DesignPhase Construction

Phase

Operational

Phase DecommissioningPhase

Environment $$$

Perfomance?

Contract

Contract- Functionality

• Service life


• Costs / time

Design Basis

• Geometry


• Reinforcement- Concrete

Execution

• Pouring- Compaction


• Curing

Use

• Loading- Exposure
  Handling over- Maintenance

Figure 4.14: Illustration of how different factors during the different stages of a concrete structure
might affect the performance of the structure.

In the process of identifying the exposures and scenarios which may lead to consequences
associated with a civil engineering activity or system it is useful to think in terms of hazard
pointers i.e. the:

 chronology of events involved

 origin of effects (natural or man-made)

 functionality of components and the success of activities