1. An underwater pipeline is designed to tranfer gas between an oil rig and the storage facility. The unit weight of the gas is given as 7gas=2.2 kN/m² and the unit weight of seawater is yw=10.3 kN/m². The pipe is made of steel (7st=78.5 kN/m?) with an inner diameter of Din= (800-t)mm and an outer diameter of Dout=(800+t)mm (t=2+0.01*(xy) (millimeters) - SEE END OF PAPER.). Check the stability of the pipeline against uplift and calculate the amount of ballast needed (7=22 kN/m”). Use a FS of 1.2 against uplift. Calculate the ballast for the following cases: a. A uniform concrete coating of thickness t is to be applied to the entire pipe; calculate to. b. Concrete weight blocks are to be installed with spacings. Blocks shall be carried to the construction site by a barge and will be settled onto the pipeline before submersion by a crane. If the crane available has a lifting capacity of 30 tonnes, calculate the spacing between the blocks. Seawater Oil Seabed