INTERPRETATION OF SHEAR MODULI FROM CONE PRESSUREMETER TESTS IN SAND

The interpretation of the elastic shear modulus obtained from cone pre ssuremeter tests is examined to assess the influence of installation d isturbance and other factors on the measurement of soil stiffness. In particular it is shown that the cone pressuremeter test can give relia ble values of unload-reload shear modulus. The typical shape of unload -reload loops is examined, and two procedures to calculate the shear m odulus are proposed. The shear moduli calculated from measurements mad e with strain arms and those calculated from volume change measurement s are compared. A method is presented that allows the relevant stress level acting around the pressuremeter during the test to be taken into account in the interpretation of measurements of the shear modulus. T he values of the moduli obtained from the cone pressuremeter are compa rable with those obtained from the self-boring pressuremeter.