Book Stochastic Design of Caisson Breakwaters: Lessons from Past Failures and Coping with Climate Change

高木, 泰士  ,  Takagi, Hiroshi

Description
Even if appropriately designed, a breakwater can still fail if it is subjected to waves stronger than what it was designed for. The possibility of breakwater failure could increase in the future due to the negative impacts of climate change, which could cause increases in sea water level and wave heights. After a long period of service the stability performance of breakwaters could deteriorate, when faced with conditions different to those for which it was originally designed. Therefore, repairs or reinforcements to existing breakwaters might eventually be necessary at some stage in order for them to fulfill or extend their working lives. To do this, it is required for planners and engineers to have adequate knowledge for deciding the strategy that would produce the best possible maintenance and design solution. The present chapter describes methods which can enable engineers to estimate the possibility of caisson breakwater failures as a result of either sliding or tilting. To take into account the randomness of waves and complex structural responses, these failures need to be stochastically evaluated by incorporating various uncertain design factors. The authors reviewed the stochastic methods for breakwater design which they developed in the past, and present how plausible it is for such modes to estimate actual breakwater failures. Also, the degradation in breakwater stability as climate change proceeds is also discussed. However, the use of stochastic methods, composed of a number of complex elements, may pose difficulties and ambiguities to practicing engineers, which could eventually hinder their adoption. Thus, in the last section a series of tables are presented in order to enable engineers to quickly evaluate the stability of a given breakwater without any complex simulations having to be carried out.
Even if appropriately designed, a breakwater can still fail if it is subjected to waves stronger than what it was designed for. The possibility of breakwater failure could increase in the future due to the negative impacts of climate change, which could cause increases in sea water level and wave heights. After a long period of service the stability performance of breakwaters could deteriorate, when faced with conditions different to those for which it was originally designed. Therefore, repairs or reinforcements to existing breakwaters might eventually be necessary at some stage in order for them to fulfill or extend their working lives. To do this, it is required for planners and engineers to have adequate knowledge for deciding the strategy that would produce the best possible maintenance and design solution. The present chapter describes methods which can enable engineers to estimate the possibility of caisson breakwater failures as a result of either sliding or tilting. To take into account the randomness of waves and complex structural responses, these failures need to be stochastically evaluated by incorporating various uncertain design factors. The authors reviewed the stochastic methods for breakwater design which they developed in the past, and present how plausible it is for such modes to estimate actual breakwater failures. Also, the degradation in breakwater stability as climate change proceeds is also discussed. However, the use of stochastic methods, composed of a number of complex elements, may pose difficulties and ambiguities to practicing engineers, which could eventually hinder their adoption. Thus, in the last section a series of tables are presented in order to enable engineers to quickly evaluate the stability of a given breakwater without any complex simulations having to be carried out.

Number of accesses :  

Other information