Research Projects

Inadequate pavement drainage continues to be a leading cause of premature failures in flexible pavements, especially under high rainfall and waterlogging conditions prevalent in several Indian geoclimatic zones. While existing empirical approaches provide limited guidance, the need for a scientifically-grounded and field-validated drainage design methodology remains critical. This project aims to develop and validate advanced subsurface drainage solutions using both conventional granular materials and geosynthetics, integrating them with a performance-based design framework. The scientific objective is to assess the drainage demand and capacity of various systems under actual highway traffic and climatic conditions. The research hypothesis is that a demand-capacity-based model, calibrated with field-monitored data, can more reliably predict drainage performance and guide material and design selection. Key experiments include the installation of instrumented pavement sections across four distinct geoclimatic zones, continuous monitoring of subsurface moisture and hydraulic responses, and post-construction performance evaluation using surface distress surveys and back-calculated moduli. Successful completion will establish a first-of-its-kind, field-validated framework for subsurface drainage design in Indian highways, enabling better material utilization (e.g., geosynthetics), longer pavement life, and significantly reduced maintenance costs. The outcome is expected to lead to updated national guidelines and broader applicability across diverse road projects. Methodology and Experiments: Laboratory-scale testing of granular and geocomposite drainage layers to determine saturated hydraulic conductivity and clogging resistance. Development of finite element hydrological models to simulate transient moisture movement under different boundary conditions. Field implementation of instrumented test sections using piezometers, moisture sensors, and temperature probes. Data acquisition over 24 months, including infiltration profiles, water table variations, and pavement distress mapping. Calibration and validation of the hydraulic model using field data to recommend zone-specific drainage design charts.