چكيده به لاتين
Carbonate soils are problematic soils that geotechnical engineers usually deal with. Extensive research on these soils show their specific conditions. The diversity of these soils is one of their characteristics. The origin and various conditions of the sediment environment lead to their different characteristics, such as shape and size, crushing capacity of grains, pore ratio and cementation rate. Persian Gulf, is among regions where carbonate soils exist. Recently, many researches have conducted experiments based on engineering behavior on carbonate soils of this region. However, behavior of these soils in unsaturated conditions has not been studied so far.
According to the effect of water - soil grains interface crescent radius (which is strongly influenced by soil texture and contacting the soil grains with each other) on matric suction, as well as the grains shape and Porous fabric of carbonate sand, it seems that the behavior of this soil in unsaturated conditions can be different from silicate soils. Therefore, in this study, behavior of carbonate and silicate sand in unsaturated conditions have been investigated by conducting a series of saturated and unsaturated triaxial tests and physical modeling of slope failure using geotechnical centrifuge. Results have been compared using back analysis. According to the results of the experiments, shear strength changing Procedure (apparent cohesion) versus the degree of saturation (in this research, soil moisture content) are determined and it is also demonstrated that specific texture of carbonate sand reduces the maximum apparent cohesion more than silicate sand.
