| The elevated pile caps is widely used in Chinese engineering structures especially in offshore structures due to the advantage of small settlement of the basic, shorter period of construction and strong adaptability. Marine engineering structure is different from the buildings on land, the structure suffer form many random laods which change with time and space in service period. Wave load is the most fundamental and important dynamic load among these load. Therefore, to study the structure under the effect of waves and earthquake is very necessary.The influence of the structure under the effect of waves and earthquake is analysed on the basis of consulting plentiful domestic and foreign documents. According to soil mechanics, ocean engineering mechanics, structural dynamics and finite element method, this paper is mainly intended to take the elevated pile caps as its research subject. A reasonable model composed of soil, foundation and superstructure is founded by finite element software ANSYS. To analyse the stress of elevated pile caps-soil-frame structure interactions under the action of waves and earthquake. The main research contents are as follows:(1)Wave theory is the basis to understand the wave effect. Calculating method about wave forces that working on the piles is introduced, which is the foundation for the calculation of wave forces.(2)Dynamic analysis is the basis of time-history analysis, structure's cycle and mode are analyzed under the interaction of elevated pile caps-soil- superstructure, which laies the foundation for the anti-seismic analysis.(3)The internal forces and deformation of pile foundation under the effect of earthquake and waves is studied. Pile top displacement, bending moment, shear of pile top and axial force were analyzed separately. The results show that the stress of the front row of the pile foundation is the biggest, which shoule be considered in the design.(4)The internal force and deformation of pile foundation is analyzed by changing the free length of pile, pile diameter, soil compression modulus and thickness of the cushion in turn to analyze in the case of other factors invariant, which can be reference for the design to choose the reasonable factors. |
