Исследование динамических свойств карбонатно-глинистых полускальных грунтов в диапазоне малых сдвиговых деформаций

Results from laboratory tests on marls are presented, which have been conducted in order to observe the behavior of marls at very small strains and determine its dynamic properties. Damping properties of marl were of particular interest, since published data on this subject is extremely limited and its theory needs further development. Rock shear modulus (G, Pa) and damping ratio (D, %) were studied by means of resonant-column method. The study was carried out on intact solid cylindrical specimens and test results demonstrated shear modulus degradation and damping ratio growth as a function of shear strain. Aside from resonant-column testing, laboratory measurements of damping ratio α(f) were carried out using geophysical ultrasonic test methods. It was found, that damping indexes, obtained from two abovementioned methods, did not correlate with each other. It might have resulted from differences in equipment operational frequencies, as damping is a frequency-dependent parameter.