A series of consolidated drained (CD) triaxial compression tests on sand with dilatancy is conducted to obtain mechanical parameters. The behaviors of large diameter monopile foundation in offshore under horizontal loading are analyzed using a three-dimensional finite element model with the finite element software ABAQUS. A lot of parameters

like stress path

friction angle

dilatancy angle and the characteristics of soil-pile surface

are taken into consideration to study the soil structure behavior

which is verified with the centrifuge modeling. Then

a reasonable finite element computational model of large diameter monopile foundation under horizontal loading including the parameter selection method of this model is established. Besides

the deformation is proposed as the control criterion to determine the horizontal bearing capacity of monopile foundation for the offshore wind turbine. With that

the pros and cons of existing methods for analyzing horizontal bearing capacity and deformation of pile foundation are discussed. Finally

it is suggested to determine the critical embedded length of monopile foundation by numerical analysis.