Assessment of Subgrade Resilient Modulus for Identifying Causes of Pavement Failure: A Comparative Analysis

This study aims to investigate the parable causes of repetitive pavement failures of the Trimohini to Baromile road section of Rajshahi-Kushtia highway in Bangladesh. The comparison of different factors causing pavement failure between Trimohini to Baromile section and other non-repetitive failure type road (Dhaka Pabna Highway) was analyzed. Dynamic Cone Penetration (DCP) tests were carried out at six distinct locations from Trimohini to Baromile section and subgrade soil samples were collected for laboratory tests to obtain physical characteristics. The strength and physical properties at selected points of both highway sections were analyzed by examining data obtained from field tests and laboratory tests. The values of the subgrade resilient modulus of Rajshahi-Kushtia highway section were lower compared to other road sections of the Dhaka-Pabna highway. In the Trimohini-Baromile highway section, pavement failure is attributed to low subgrade resilience modulus and excessive moisture content. Conversely, the Pabna Bus Terminal-Madhupur Section maintains a higher subgrade resilience modulus, leading to a stable pavement condition. This study highlights the significance of subgrade resilience modulus and moisture content on pavement failure or stability. The findings contribute to a better understanding of subgrade behavior and can inform the design and maintenance of highway infrastructure to enhance serviceability and durability.