Determination of Root-Soil Structure Effects on Soil Strength from Direct Shear Test

Abstract

Slope stability problems are one of the important issues that require engineering solutions. Slopes are subject to loss of stability due to natural or man-made reasons. In recent years, solving engineering problems with nature-friendly methods for a sustainable future has come to the fore more than ever before. So, the vegetation method is one of the efficient methods that can be preferred in this regard according to some studies. When the earthquake effect is evaluated, the effects of root structures on soil strength should be examined. The most important problem with engineering solutions to be used in slope reinforcement with vegetation is the complexity of solving root behavior with current engineering methods. In order to better understand and simplify this complex structure, experiments were carried out in the laboratory with a root structure sampled from a tree. The failure behavior of the slopes takes place in a certain slip plane, therefore, the shear box test, which operates based on failure in a certain plane with a similar principle, is preferred. In the study, the effects of variables such as different diameters of roots and volume ratios of root structure properties on soil strength were evaluated by experiments. Soil-root structures were created for different reference root diameters and the experiments were repeated by changing the soil-root densities at the selected diameters. It is expected that the difficulties encountered in computer modeling of the complex structures of roots will be overcome by using simpler root models developed from the obtained relations.