Engineering Challenges and Options in Remediation and Prevention of Permafrost Coastal Erosion

Erosion along the permafrost coasts has been accelerating, threatening the wellbeing of many Alaskan communities. This paper synthesizes and presents the engineering challenges, the costs of erosion control measures, and the remediation and prevention measures for permafrost coastal erosion through case histories. The review and synthesis of the state-of-the-practice of permafrost coastal erosion controls can be used to identify measures and construction materials that are proven effective in Arctic coasts. The synthesis shows that revetments built with rocks have the least reported failures and are the most common measures applied along the permafrost coasts. For seawalls, bulkheads, and groin systems, reported failures are mostly associated with displacement, deflection, settlement, vandalism, and material ruptures. The effectiveness of beach nourishment is inconclusive; only one successful beach nourishment project is reported in Alaska, but it is located outside the permafrost region. This study also shows that the unit cost of the erosion control measures in Alaska has continued to increase over the past 40 years.