Studying the effect of the saturation degree on the properties of dense sandy soil through laboratory loading tests

Abstract

In this research, the experimental method was adopted on samples of sand soil taken from the city of Tartous (Al-Hamidiya village), and the aim is to study the effect of the degree of saturation on the properties of compacted sand soil (ultimate pressure - coefficient of linear deformation modulus - shear specifications - collapse shape) by means of several Laboratory models. To achieve the aim of the research, experiments were conducted for the basic Physical and classificated properties of the soil, the direct shear tests were performed at the different saturation degrees, and a series of Laboratory loading tests were conducted fora model footing atop compacted sand, the dry density was kept constant for all tests while the degree of saturation was changed within the range [0-50]%.The results were analyzed and discussed, and it was found from the results of the loading tests that  the ultimate pressure increased non-linearly with the increase in the degree of saturation within the range [0-50]% and the values of the increase ranged between [2-3.4] times the ultimate pressure in the dry state, and it was also shown that the linear deformation modulus changed in a non-linear manner, in the beginning the linear deformation modulus increased with the increase in the degree of saturation until reaching the largest value at a specific degree of saturation and with the increase in the degree of saturation the linear deformation modulus decreased.        

The results of direct shear tests showed a slight decrease in the internal friction angle by 4.3% with the increase in the degree of saturation, while it was observed that the apparent cohesion increased with the increase in the degree of saturation until a specific value was reached at which the value of the apparent cohesion is maximum, and with the increase in the degree of saturation after this value the values of the apparent cohesion decreased.

The results of direct shear tests showed a slight decrease in the internal friction angle by 4.3% with the increase in the degree of saturation, while it was observed that the apparent cohesion increased with the increase in the degree of saturation until a specific value was reached at which the value of the apparent cohesion is maximum, and with the increase in the degree of saturation after this value the values of the apparent cohesion decreased.