YOUNG'S MODULI OF SANDS UNDER DIFFERENT TYPES OF LOADING

Experiments were conducted on Ottawa 20-30 sand in a resonant column device using three types of loading: sinusoidal, random and impulse to study the effect of loading type on the Young's modulus of sand. Sand specimens were excited longitudinally with one of three types of loading at three different confining pressures. In the sinusoidal tests, excitation signals were generated by a variable frequency sine-wave oscillator. In the random tests, input signals were generated by a white-noise generator. A pulse signal generator was used in the impulse tests. Input and output signals were analyzed by an FFT analyzer in the random and impulse loading tests. The Young's modulus of the sand specimens and axial strain amplitude induced in the specimens under each condition were determined. The Young's modulus of sand was found to be affected by loading type, however, the effect was not very significant.