Study On The Structural Type Of The Jack-up Truss-leg

With the rapid economic development, the growth of the offshore drilling market is being driven by high demand and the prices of crude oil and natural gas. The jack-up rig has been mostly applied in offshore engineering. As the main structure affecting the safety of the platform, truss-type legs are most widely used on the jack-up rigs. Leg structure drawing should indicate the main parameters of a leg to get the certificate of classification societies, such as shape, demission, joint, material, arrangement and process requirements.Our country has made a break-through in the independent research and development of the jack-up rigs, however, most shipyards and design companies only have capacity for structure design and production design. The basic design and the concept design are still need to be bought from foreign companies. Therefore, a lot of basic work need to be done. Leg design method and design basis need to be stored in a database.This paper presents6truss-leg jack-up rigs (300ft-400ft). Their legs are transformed into equivalent beams to be analyzed according to society rules. Leg parameters are collected, and then wave loads and structural strength of X type, K type and int-K type are compared respectively.Taking a300ft jack-up rig for an example, this paper introduce the chord and the bracing construction, as well as leg section construction and assembling.