3. All structural elements were designed according to 
ACI standards for reinforced concrete construction. 
4. Design live load for the platforms were: 
(a) with multiple decks 
eg ILralaye Cheyelieiig’ GusGy Hed Lo Go ol. 6- ot 2EO) josie 
aincraktsitonage deck isu.) scien 25 On pss 
pensonnedladeckws cigs 1s: tel tates) LOOM psi 
(b) with single slab deck 
fltichte/istoragedeck: . j.c0% . . 400) pst 
5. Design live load was considered distributed uniformly 
throughout; no allowance was made for partial loading. 
6. Concrete having a density of 150 yee and a compressive 
strength of 6,000 psi was used in all design estimates. 
7. All elevated and semi-submersible platforms were held to 
a minimum clearance of 50 feet between the bottom deck slab and the mean 
water surface when the platform was loaded with the full design dead 
load plus live load. This specification insured that wave uplift on 
the deck will be prevented in all but exceptionally high sea states. 
8. All platforms were designed with a minimum freeboard of 
60 feet to insure that deck washing does not impede aircraft landings/ 
takeoffs as well as cargo transfer and storage operations. 
Selected geometries given in Table 3.1 are discussed in the para- 
graphs that follow. 
Structural Design Approach 
Spacing of Buoyant Support Elements. Since elevated and semi-sub- 
mersible platforms in the 300 x 300-foot size range exhibit poor trans- 
verse and longitudinal stability, it behooves the designer to minimize 
the weight of the deck. A trade-off made early in the study showed 
that the weight for both the solid slab and multi-level decks could be 
minimized without unduly increaseing the weight of o ther components 
(primarily the vertical and/or horizontal buoyant support cylinders 
and solid ballast) if the decks were assumed to be uniformly supported 
at 50 and 43-foot centers respectively for the single and multi-level 
decks. 
3-19 
