Liquefaction: Behavior Evidence, Prediction, and Prevention

Today’s Menu What is Liquefaction How is it expressed How can we predict its occurrence How can we prevent it from happening

What is it Worm’s eye view Professor’s eye view

Cyclic Mobility Normally stable soils cross phase line Stress reversals cause it to happen over and over

Expression of Liquefaction Sand boils and flows – free-field Landslides – static lateral stress Foundation Failures – surface loadings

Empirical Approach, Shear Wave Velocity

Empirical Approach, Cone Resistance

Stress Reduction Factor

Empirical Strength Based on N, Blow Count

Prevention/Control Soil modification Reduced Loads Drainage (pore pressure relief)