Volume 11, No. 1, 2017
Received: 2016/12/13, Accepted:
Authors:
Alireza Negahdar; Shima Yadegari; Siyab Houshmandi;
Abstract:
Investigation of mechanisms and factors influencing the creep behavior of soils is one of the main requirements in geotechnical engineering. In this paper, one-dimensional single-stage, stepwise and
overloaded-unloaded creep tests are carried out using oedometer apparatus on dried in air and water-saturated sandy clay soils at different stress levels, in order to investigate parameters affecting the creep behavior, such as: stress level, stress history and pore water. The creep mechanisms are explained with respect to contacts
and deformation of particles. Data analyses are explained based on relationships between the coefficient of secondary compression (Cα) and change in void ratio (Δe). Test results showed that in water saturated samples at low stress level, due to higher sliding ability and lower friction, a large amount of creep deformation occurs and with increased stress level, the creep rate decreases. But, in dry samples, stress increment increases creep rate. Further, the creep rate in overloaded-unloaded test is higher than that in single-stage test, and this in turn accelerates the creep.
Keywords:
Creep, One-dimensional creep test, Single-stage test, Stepwise test, Overloadedunloaded test