Reliability of Timber Fender Systems in Waterfront Facilities

Abstract

Due to the deterioration of existing timber fender systems in waterfront facilities, high performance, composite replacement components for these structures are in demand. The performance criteria for these replacement components must meet or exceed the performance of existing timber systems. For this reason, a reliability analysis of existing timber fender systems has been performed to establish (1) the level of performance in existing timber fender systems; and (2) target performance levels for new composite replacement components. The design of waterfront fender systems is based on energy considerations. The most widely used and accepted method for determining the applied energy created by the docking ship is the kinetic energy method. Based on the applied kinetic energy of the docking ship and the response of the timber elements, a load model was developed to investigate the effect of several parameters on the system reliability. Investigations were conducted to determine the effect of variability and correlation among material properties on structural reliability. Results showed that as variability decreases and correlation increases, reliability increases. The effect of load-duration assumptions on the structural reliability was also investigated to illustrate the differences in existing fender system design criteria and current timber design standards. The results of the analysis on the timber systems are being used to set a standard for wood-plastic composite elements that will be used as replacement components in these systems.