Enhancing Stability of Collapsible Soils in Al-Hashimyia, Iraq: Geotextile Reinforcement under Dynamic Loading and Varied Saturation Levels

A laboratory study was conducted in the Hashimiya region in mid-Iraq, in which collapsible silty clay soil was subjected to control mechanical energy. Three random soil samples were spatially selected and carefully mixed for later testing. Each test was repeated three times and the results average was taken. The conditions included soil wetting up to 50%  saturation (S) and dynamic power loads up to 300 kJ. The aim was to evaluate the efficiency of geotextile reinforcement in resisting soil collapse due to soil wetting. Tests were conducted using a test box and a specific amount of dynamic energy, various experiments were performed. The geotextile layers were placed within the soil column, in multiples of 10 cm apart. Remarkably, under conditions of dynamic energy of 200 kJ and S= 0.35, the soil collapse potential (Ie) was reduced to less than 5% with the implementation of geotextile layers spaced 10 cm apart. Subsidence reduction percentages (SR%) varied depending on the saturation levels and number of geotextile layers, with higher saturation levels and larger distances between layers leading to lower SR% and vice versa. It is found SR is 3.95, 19.78, and 40.58% in the case of 1, 2, and 3 layers of geotextile reinforcement, degree of saturation of S= 0.25, and 300 kJ dynamic energy, whereas, SR is 2.16, 14.79, and 30.44% in the case of 1, 2, and 3 layers of geotextile reinforcement, degree of saturation of S=0.5 and 300 kJ dynamic load. This research emphasizes the critical role of geotextile reinforcement in mitigating collapsible silty clay soil instability and provides insights into effective for enhancing soil stability in areas exposed to such geological challenges.