Three dimension earthquake response analysis of liquefaction foundations

The fully coupled three-dimension effective-stress dynamic analysis procedure is developed and liquefaction foundations are analyzed.The influence of different soil parameter,different soil layer and different additive pressure on anti-liquefaction nature of the liquefaction foundation is discussed.The research shows that the excess pore water pressure of natural saturated sand foundation increases as depth.In different depth,the arriving time of the peak value of pore pressure is later than that of the peak value of earthquake acceleration.With decreasing of input earthquake acceleration,the excess pore pressure starts to dissipate or keeps constant in deep layer,and it keeps constant or has little rise in shallow layer.This phenomenon is related to soil parameters and earthquake loading etc.The soil parameters have much influence on the anti-liquefaction nature of sands,for the littler initial void ratio and the bigger relative density, the anti-liquefaction capability of sands is more strong.Additive pressure is useful for improving the anti-liquefaction capability of the foundation;with the additive pressure increasing,the pore pressure ratio decreases.Additive pressure can restrain the effect of excess pore water pressure.