Multi-Hazard Mitigation Plan: 07. Earthquakes

Home

Chapter 7:Hazard Analysis—Earthquakes rig. l d� cv • Figure 7-8. Aerial image of Kawaihae Harbor Kawaihae Harbor sustained major damage from liquefaction and lateral spreading. Sand boils were observed throughout the harbor area. Much of the fill material under the shipping container handling yard consists of dredged fill. As this material liquefied, the resulting lateral spreading caused significant vertical settlement of the asphalt pavement, and lateral displacement of the pile supported concrete piers. Large areas of the asphalt yard, had settled up to approximately 6 inches. A series of cracks with widths ranging from approximately 1/4 inch to several inches were observed roughly aligned parallel with the shoreline. Cumulatively, these cracks displayed lateral spreading of 6 inches or more. Pier 1 displaced as much as 6 to 12 inches laterally towards the harbor. This movement indicates that the piles were moved and/or distressed by the lateral spreading of the liquefied soil beneath and landward of the pier. Port Damages The most pronounced damage at Kawaihae was the failure of 1950's era Pier 1. The 1950's era Pier 1 which includes a concrete bulkhead wall, tie rods, anchor block and surrounding structures experienced a significant amount of damage. Primary damage and displacements greater than 15 inches occurred to Pier 1. Visible damage to the pier structure included: • Longitudinal cracks in the bulkhead cap, concrete sheetpile and rock revetments. • Yielding and necking of the tie rods, but no breakage with 4-6 inches lateral translation and 12-15 inches movement in the rip rap at the north end of the pier. • Significant settlement behind the anchor block and in pavements. 7-9 Hawaii County Multi-Hazard Mitigation Plan