Wave impact load on jacket structure in intermediate water depth

The aim of this study is to estimate impact forces on a jacket using the improvised methodology and to propose a slamming coefficient for the jacket structures. Four types of structures have been discussed in this study, single cylinder (SC), legs with connecting braces in wave direction, legs with connecting braces transverse to wave direction and jacket structure. The SC case was analyzed using the improvised methodology and the obtained slamming coefficient was validated with the existing literature. Based on this initial validation, the methodology was extended for other models. Four loading cases were identified based on the location of the wave breaking. The impact load estimated was compared with theoretical formulas given by Goda et al. (1966), Wienke and Oumeraci (2005) for all models. The slamming coefficient (Cs) was found for wave characteristics having spectral bandwidth ratios of 1 and 0.75. For both the wave characteristics, the Cs was found to be higher for the loading case, when the wave breaks in front of the structure. The Cs varies between 2.2 and 4.6 depending upon the wave characteristics, with maximum obtained for 0.75. The method used in this paper can be used for estimating impact loads on complex structures.