Methodology for the simulation of the construction of a breakwater taking into account climate and construction accident risks

This paper presents a method to simulate the construction of a caisson breakwater in order to evaluate the risks involved in its construction. A computer model of the construction process that a contractor would follow to build a caisson breakwater was developed, with the wave climate for each month of the duration of works modeled using data obtained from the NOWPHAS Reports. Possible damage to the caisson was determined using a deformation-based reliability design method that included sliding, tilting, overturning of the caisson and erosion of the toe armour and foundation material. The model included possible delays due to adverse weather, reconstruction of damaged sections and construction accidents. By using the Monte Carlo simulation technique, the expected cost and time to finish the breakwater could be obtained, allowing to determine the risk associated with the breakwater construction. Thus, it is possible to determine when would be the most appropriate time to begin construction and the likelihood of encountering problems during the construction phase. A case study of the breakwater construction for Honshu island in Japan is shown, with the results comparing well with the experience of Japanese contractors.