Investigation of the effect of hemp-based woven geotextiles on sub-soil bearing capacity

Soils which have low bearing capacity frequently encountered in geotechnical engineering. The use of geotextiles as reinforcement are among the various methods to improve bearing capacity of such soils. However, geotextiles produced from synthetic fibers obtained from crude petroleum oils cause negativities in terms of environmental friendliness and sustainability, which gaining great importance today. This situation has led researchers to look for natural fibers that can be an alternative to traditional synthetic fibers used in geotextile production. In this study, environmentally friendly hemp-based woven geotextiles (Geo-Hemptex) were produced and their effect on the bearing capacity of the soil was investigated. Firstly, the physical and mechanical material properties of Geo-Hemptex were determined. In order to determine the contribution of Geo-Hemptex to the shear strength of the granular soil and the interface strength with granular soil, triaxial pressure tests and interface shear box tests were carried out. Plate load tests were conducted to determine the contribution of Geo-Hemptex to the bearing capacity of the soil. During the study, experimental studies were also carried out in order to understand the biodegradability behavior of Geo-Hemptex in the soil. All mentoined experiments were repeated for synthetic woven and non-woven geotextiles used in the industry, which have similar tensile strength to Geo-Hemptex. After the experimental studies, 2D modeling studies were carried out using the finite element method. As a result of the study; it has been observed that Geo-Hemptex provides almost equal improvements in the shear strength of granular soil with synthetic woven geotextile. Additionally, it has been determined that Geo-Hemptex provides higher adhesion values at the interface it forms with the soil compared to synthetic woven geotextile. While the contribution of Geo-Hemptex to the soil bearing capacity was almost equal to synthetic woven geotextile, it was much higher than non-woven geotextile. As a result, it is thought that Geo-Hemptex can be a more economical, environmentally friendly and sustainable alternative product instead of synthetic geotextiles used in the sector.