Existing culverts are often retained and extended during highway widening projects. Many Reinforced Concrete Box Culverts (RCBCs) were originally constructed using a stepped configuration, with slab thickness decreasing as the embankment height reduces along the culvert. In widening applications, Lightweight Material (LWM) fill is commonly placed over the thinner culvert sections to prevent an increase in net loading.
     This web application is designed to help users evaluate a range of LWM configurations within the existing embankment limits, supporting the identification of optimal lightweight material fill solutions.