Mechanistic Analysis of Subgrade Soil Reinforced with Modified Jute Geotextile

Abstract

Design and construction of flexible pavement on soft subgrade soil is a daunting task to achieve a target strength level due to its expansive characteristics. Application of modified jute fibre reinforced subgrade layer is a promising technique for enhancing subgrade soil strength, keeping its biodegradability intact during the design period. In this study, locally available natural jute geotextile (NJGT) and modified jute geotextile with bitumen (BJGT) and low-density polyethene sheet (PJGT) were used for reinforcing natural clayey and silty soil. Series of laboratory strength related tests such as resilient modulus (Mr) using repeated triaxial tests, California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS), were performed on parent soil, natural and modified jute geotextile reinforced soil samples. Tests results depict that CBR values were increased up to 1.4–5.3 times for three layers of natural and modified reinforced soil samples. Whereas, Mr values were increased up to 1.2–3.0 times for two layers of natural and modified reinforced soil samples respectively as compared with parent soil. The proposed soil reinforcing models were simulated by designing crust composition for the vehicular loading of 1–7 million standard axle load repetitions. The performance of the proposed crust composition was assessed by using KENLAYER program. Results show that the performance of reinforced pavement models was enhanced regarding rutting repetitions as compared with parent models. Thus, this study intended to overcome the biodegradability aspect to improve the durability characteristics of JGT reinforced subgrade soil for paving low volume road in the expansive soil region.