摘要：OWTs （offshore wind turbines） are currently considered as a reliable source of renewable energy. OWT support structures account for 20%-25% of the capital cost for offshore wind installations. Pre-feasibility studies involving estim.tion of prelim.nary dim.nsions of the wind turbine structure need to be perform.d for initial costing to arrive at the com.ercial viability of the project. The m.in objective of the paper is to obtain prelim.nary configuration for com.ercial viability and approxim.te sizing of the foundation pile. Design equations and nom.gram. are proposed for quick prelim.nary design of m.nopile founded wind turbines located offshore of Gujarat. Param.tric studies are carried-out on various configurations of a hollow m.nopile by varying water depths and properties of sand. A nonlinear static analysis of substructure is perform.d considering aerodynam.c forces and hydrodynam.c forces for various structural and soil param.ters. The sub-structure design of wind turbine is based on API （Am.rican petroleum.institute） standards. A sim.lified design m.thodology for m.nopile support structure under extrem. loading condition is presented based on m.ltivariable linear regression analysis. The input variables for the regression analysis are hydrodynam.c data, angle of internal friction of sand, and the output variables are length and outer diam.ter of m.nopile. This sim.lified m.thodology is applicable in pre-studies of wind power parks.