Abstract
The concept of performance-based seismic design has been introduced in the 2004 revision and 2007 revision of the Japanese design codes for coastal structures and port structures, respectively. However, the performance criteria for coastal structures is given as the allowable settlement at the crest of the seawalls, and there is no discussion on the allowable horizontal displacement. In reality observed in 1995 Hyogoken-Nanbu earthquake disaster, some seawalls lost their function of continuous walls due to uneven horizontal displacement of the walls. Thus, in this paper, the allowable level of horizontal displacement of seawalls is discussed from the observed damage cases, and the performance criteria is proposed. Then, the feasibility of the proposal was discussed in detail with a project of the remediation of sea walls.
