EFFECT OF FREQUENCY CONTENT ON THE DYNAMIC PROPERTIES OF THE SAND

Abstract

Under repeated loads, stress-strain and strength properties of soils play an important role in solving the engineering problems. The resistance of a material is defined by the slope of the initial part of stress-strain curve. However, this value changes due to cyclic loading and decreases cycle by cycle. As a result, deformations occur on the ground and resulting structural damage. Engineering properties of soils (such as modulus and damping properties of soil, shear wave velocity, unit weight etc..) must be known to minimize the effects of earthquakes. Another important parameter is the frequency content of earthquakes which directly affects the wave propagation through the soil. In this study, the effects of frequencies, obtained from different earthquakes, on the dynamic characteristics of the soil have been investigated. A dynamic triaxial test set has been used to examine the dynamic properties of soils. The variation of dynamic properties of sand samples under the experimental conditions has been determined for regular and irregular loading types.