This paper summarizes a numerical study on damage modelling of reinforced cement concrete beam on a marine berthing jetty. In this study, the post cracking behaviour of reinforced cement concrete member on a berthing jetty is modeled using damage plasticity approach. The simulated numerical model is closer to the complex non-linear post-damage characteristics of reinforced cement concrete members.  The method for concrete modelling applied in this research is based on damaged plasticity constitutive modelling, which the only method that is found to include non-linear characteristics of concrete under tensile and compresive loads. This method has considered plasticity conditions, and stiffness reduction under progressive damage conditions.  The evaluated model is applied for damage detection study using frequency based and modal based damage parameters.