POST-EARTHQUAKE REPAIR AND IMPROVEMENTS, SAN VICENTE, CHILE

摘要

The magnitude 8.8 earthquake of February 2010 in Chile dealt a heavy blow to the 600 meter (2,000 ft) wharf structure at Berths 1, 2, and 3 of the San Vicente Terminal Internacional in the Biobio region of Chile. Earthquake-induced liquefaction and lateral spreading in the upland fill and wharf slope resulted in permanent wharf lateral deflections in excess of 600 mm (24 in), along with associated damage to concrete piling and pile-to-cap connections. This paper presents the post-earthquake repair and rehabilitation program for the wharf structure. The proposed rehabilitation strategy consisted of two phases: first a structural assessment of the post-earthquake conditions, with recommendations for short-term repairs and restrictions on operating criteria, followed by a structural retrofit program designed to stiffen the existing structure and provide a new lateral-force resisting system. An innovative approach to the seismic retrofit was used, which incorporates a combination of new plumb piles behind the wharf with ground improvement to ensure ample lateral strength and ductility capacity of the structure. The wharf retrofit also included a new apron structure in front of the wharf, designed to improve the local stability of existing slender piling (impacted by P-delta effects), with the added benefit of providing support for future crane rail installation and increased dredge depth. Finally, a 200 meter (656 ft) finger pier extension was included in the program, bringing the structurally retrofitted 4-berth system to a total combined 800 meters in length, designed to the most current seismic design standards.