Rational Approach to Performance-Based Design for Mooring Loads on Marine Structures

The ASCE COPRI committee on the Design of Piers and Wharves is currently developing a new minimum design standard intended to address loads specific to marine structures that are not addressed in ASCE 7 or ASCE 61. Two of the most common load types that the other ASCE standards do not cover are the design for mooring and berthing loads, which are transferred to the structure via specialized hardware attachments. These loads depend on the type of vessels calling at a facility as well as the environmental conditions under which those vessels may arrive or stay at the berth, making them complex loads to determine and parameterize. One goal that the committee has set out to incorporate into the design of mooring and berthing anchorages and structures is the inclusion of a performance-based approach for these analysis methods. Performance-based evaluations have become common in seismic design and involve determining performance objectives that provide one or more combinations of design events and allowable damage levels. This paper intends to address the philosophy of how a performance-based approach may be applied to the design of marine structures for mooring loads, with the intent that this approach may be incorporated into the new minimum design standard.