The Research On Pore Water Pressure Response To Waves In Sandy Seabed

The analysis for dynamic stability of seabed or offshore foundation under wave loading is of practical significance in the design and construction of offshore and coastal structures. When wave propagate over the ocean surface, a sequence of wave pressure is induced on the seafloor. The wave pressure induces a stress field and associated pore water pressure fluctuations within the seabed. With excess pore and diminishing vertical effective stress, part of the seabed may become unstable or even liquefied. The instability of the seabed has been responsible for the damage and destruction of offshore structures. So it has importance in theory and applied value of engineering to research the dynamic pore water pressure responses of sandy seabed under waves loading are developed. The paper analyzes thoroughly wave-induced pore water pressure on plane seabed and plane seabed with vertical wall by means of experiments. Linear regular waves and cnoidal waves are made in the experiments. Comparing all graphs presented for wave parameters, it is found that the wave-induced pore pressure is more significant affected by wave height and wave period, rather than by water depth. And the variations of pore pressure with the wave height and wave period and water depth have also been discussed. The standing wave-induced pore pressure in the vicinity of the composite breakwater is investigated. Based on dynamic elastic consolidation theory and simplified sea-bed to two dimensional sea-bed, the paper establish FEM equations for solving transient response of seabed, and works out computer programs. Compared with measured pore water pressure in seabed, calculated results show that elastic theory is valid for sandy seabed. The programs can work for the seabed with complex boundary under the action of regular waves and cnoidal waves.