Author(s): Jorgen S. Steenfelt; Guillaume Albert; Carsten Sorensen
Linked Author(s):
Keywords: Musandam; Pile design; Pile driving; Horizontal load testing; Limestone; Jetty; Berth
Abstract: The Musandam Rock Loading Facility is located close to the Strait of Hormuz, in Aisha Bay, Oman. The facility designed consists of a Jetty for Bulk Loading of Vessels up to 80,000 dwt and Barges and a Berth for Armour rock loading of Barges. The Mooring and Breasting Dolphins and Loading Platforms designed are all founded on vertical tubularO1.422 m steel piles driven into substrata of limestone gravel interbedded with hard layers of Caprock, Calcarenite/Calcirudite or Calcilitite. Due to delays in ground investigations considerable uncertainty was attached to the pile length required. It was hence decided to use the initial pile driving for the Barge Berth and the Main Jetty as a means to provide the soil stratification based on the variation in dynamic pile capacity. Based on the initial evaluation of driving results it was clear that the piles would have to be very long (in excess of 40 m) in order to meet the axial capacity demands for the Main Jetty loads as the piles did not plug. Due to the risk of refusal in high lying very strong caprock layers the Contractor would not allow artificial plugging by reduced cross sectional area as this would preclude drilling through the hard layers from inside the pile. Thus, an alternative plugging method was developed saving about 10 m driving depth (as a minimum embedment was still required in order to accommodate horizontal loads). The paper describes the development, features and benefits of the plugging method. It summarizes the results of the dynamic driving records and verification of sufficient pile capacity and the results of horizontal loading tests to verify the requisite horizontal capacity based on assumed p-y curves.
Year: 2010