INCIPIENT MOTION RESPONSE DETECTION OF ARTICULATED COASTAL REVETMENT UNDER WAVE LOADING

Edmond J Russo,Heather Smith,Clinton S Willson

doi:10.9753/icce.v32.structures.14

Abstract

Articulated coastal revetments (ACRs) are armoring options for abating earthen levee wave erosion. Stability criteria for ACR design typically allow initial, minor damage during design wave loading conditions (USACE, 2006). Minor wave damages may worsen progressively if not repaired before another design wave loading event. If minor ACR damages evolve under wave action to the point of unraveling, the underlying levee will become exposed to wave forces that could result in breaching (Pilarczyk, 1998). Vulnerability exists in this scenario for catastrophic flood risk management system failure. Current ACR stability limits for maintaining structural integrity under wave attack exist between the thresholds of structure incipient motion and that of initial damage criteria. Using an ACR stability limit that maintains structural integrity would greatly reduce the potential of repeat damage resulting in armor failure. A design challenge exists due to a knowledge gap in detecting and analyzing ACR performance between the thresholds of incipient motion and initial damage (Herbich, 1999). In this research, the threshold of incipient motion for ACRs is explored through small-scale experimentation. Data analysis, including correlations between hydrodynamic forcings and structure responses, extended our understanding of ACR system behavior in specific structural configurations and wave loading conditions.

Highlights

Pilarczyk (1998) explains that wave action impacts have the potential to result in soil erosion on the seaward faces and crown of exposed earthen dike structures
Given the motivation of this manuscript that irregular Articulated coastal revetments (ACRs) maintenance has the potential to introduce system performance vulnerabilities, our research explored a new lower limit near the threshold of equilibrium that preserves the design integrity of the ACR structure under specific wave loadings
In the following, we present results from one ACR test configuration under a wave height and period combination that was minimally able to induce incipient motion of the ACR

Summary

Introduction

Pilarczyk (1998) explains that wave action impacts have the potential to result in soil erosion on the seaward faces and crown of exposed earthen dike (i.e., levee) structures. A field prototype-scale investigation was conducted in coastal Louisiana to assess the performance of ACRs in resisting a range of wave loading conditions (Russo, 2003). Previous work and this experiment demonstrated an increased need for understanding the processes leading to the incipient motion of ACR systems and translating this to the development of suitable design procedures. System design integrity must be ensured during construction to achieve expected design performance

Results

Discussion

Conclusion