THE EFFECTS OF DAMPING ON THE INTERPRETATION OF GEOPHYSICAL MEASUREMENTS

Measurements of damping in situ as a function of strain are described. Three methods were used: hammer damping, resonance of an embedded pipe and hysteresis due to cyclic loading. All methods show damping in boulder clay which indicates that anelastic behaviour must be taken into account. There is some evidence that damping is dependent on time as well as strain. These measurements are used to produce two class A predictions of the time-dependent settlement of loaded pads that were within 20% of the observed values. Suitable viscoelastic models are considered.