In-situ Answering Pore Pressure Under Wave And Its Application To Stability Analysis Of Silty Seabed

Silty sediment is very common in shallow marine sediments,especially in delta area of large rivers. Silt is a kind of soils between sand and clay and its behavor is different from sand and clay,especially its dynamic behavor under cyclic loading is more complex.And excess pore pressure play an important role in dynamic behavor of silt soil and its change can affect seabed stability directly.This thesis is supported by "863" projects-"In-situ test technique of seabed soil".The relation between excess pore pressure and wave in silty seabed is studied by model experiment of answering pore pressure under wave. And a new relation between liquefied excess pore pressure and effective stress is assumed according to this experiment.The result is applied to an analysis system of excess pore pressure and silty seabed stability.This system is written by Visual Basic 6.0 and Excel(Visual Basic Application).This system can show excess pore pressure curve and wave curve during any time length in one month at any test depth and also can show excess pore pressure curve in scope of test depth at the same time.From these curves,effect of wave intensity on excess pore pressure and effect of wave on answering depth of excess pore pressure can easily obtained.At the same time,the system will show a total curve by elasticity theory and theory of effective stress,which will show strength change of seabed soil compared to excess pore pressure. And the system will also give more detail liquefaction potential analysis of seabed soil by the relation between excess pore pressure and effective stress from theory of effective stress and the model test.