Time-dependent reliability analysis of anchored sheet pile walls

Flood defence maintenance strategies require understanding of the time-dependent behaviour of flood defences. Quantitative risk and reliability methods provide a rational decision-making basis for flood defence management. Failure mechanisms influencing the flood defence reliability are expressed by a limit state equation and organised in a fault tree. One or more random variables in the limit state equation may be time-dependent. Quantitative information about and understanding of time-dependency of flood defences is often limited. A modelling methodology identifying the relevant variables and uncertainties involved with time- dependent processes, the character of the process and appropriate statistical models is therefore introduced. The modelling methodology is demonstrated on anchored sheet pile walls in a flood defence system in the Thames Estuary.