Stabilization of Subgrade Using Geosynthetics.

Abstract

Dealing with weak subgrades in road construction emerges innovative engineering resolutions to challenge their adverse effects on construction durability, safety, and cost-efficiency. Weak subgrades contribute to pavement settlements, resulting in frequent and costly maintenance, reduced load-bearing capacity, and safety risks. Conventional treatment methods cause various challenges such as cost, time, and environmental concerns. This research aims to investigate the effect of geosynthetics in improving weak subgrade performance, considering geosynthetic type and location within flexible pavement structures. In accordance with Sri Lanka’s CIDA guidelines, which regulate a minimum subgrade 4-day-soaked California Bearing Ratio (CBR) value of 5%, this study attempts to develop a predictive model capable of estimating the 4-day soaked CBR value of subgrade soil while taking changes in moisture content into consideration. The research findings exhibit the efficiency of applying geosynthetic layers at the subgrade-subbase interface in dramatic augmenting the ultimate load-bearing capacity of weak subgrades, especially those with 4-day soaked CBR values below 5%. Geosynthetics appear as a promising, cost-efficient, and environmentally sustainable solution to mitigate the challenges associated with weak subgrade soils in road construction, offering the potential for enhanced construction durability, safety, and cost optimization.