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PAG Earthquake Damage Repair and Modification at Wharf Berth F3 – F6

Guam suffered severe damages to its infrastructure buildings including the only commercial port on the island during the 1993 8.1 magnitude earthquake. Black was the low bidder on the earthquake damage repair project for Port Authority of Guam.The project involved reconstruction of about 600 LF of dock space. The new project design involved a new wharf deck supported by 24”square piles on densified soil. Huge box steel sheet piles were driven at transition areas of the new wharf and the existing dock. The project also included all utilities for the new wharf such as water, power and telephone lines. New bollards, cleats and fender system were installed as part of the new dock. Impressed cathodic protection was installed on the new dock and sacrificial anodes installed into the new and existing sheet piles. One major part of our scope was the demolition of the existing dock which included removal of deadman sheet piles, removal of existing H-piles supporting the crane rail beams, and underwater cutting of the existing bulkhead sheet piles. Erosion control was also part of the project which included placing filter fabric and rip-rap stones underwater. The original design of the new dock was a conventional pour-in-place structure. BCC had proposed VECP to the owner which resulted in a shared cost savings to both BCC and Port Authority of Guam.

Challenges/ Resolutions

Underwater excavation to the required sloping grade after the soil densification (vibrofloatation) had to be performed on two shifts to meet the schedule. Driving the 24” square piles on a sloped grade was attained by using huge fabricated templates to meet allowed tolerances on pile alignment.

Super Typhoon Paka hit Guam during the pile driving stage causing damages to completed works and resulting in delays on the project. BCC increased its resources on the job and was able to complete the job 60 days ahead of the agreed completion date.