|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1995 : ¥1,100,000 (Direct Cost : ¥1,100,000)
The dynamic response of seabed is one of the important subjects for the design of gravity type of offshore structures. The dynamic response of seabed results from the dynamic interactions of the seabed-structure-fluid systems.
In this study, an experimental study and a numerical analysis were carried out to evaluate the dynamic response of seabed in terms of a dynamic interaction problem of the seabed-structure-fluid system under water waves.
Two dimensional model experiments with the gravity type structure were carried out to determine the response characteristics of the excess pore water pressure under the water waves. From the theoretical point of view, the boundary integral equations were formulated to solve the dynamic interaction problems of the seabed-structure-fluid system. In this analysis, the seabed is assumed as a fluid-saturated poroelastic material. The fluid is assumed to be a perfect fluid and the structure is to be a linear elastic body.
The main results of this study are as follows :
1) The pore water pressure decreases exponentially as the seabed depth increases.
2) As the soil depth increase, the phase time of pore water presure becomes longer.
3) It was found that from the numerical analysis, the deformation, principal stresses and pore water pressure in a model seabed were influenced by the motion of a structure associated with wave length.