Investigating the causes of roadway collapse in culvert sections: the case of çağlayan

Structures constructed to protect highways from natural disasters such as external precipitation and landslides are called "engineered structures." These structures are used, in particular, to safely remove groundwater, which can cause the greatest damage to highway infrastructure. Culverts are engineered structures constructed on highway or railway infrastructure to facilitate the drainage of rainfall-induced water flow without damaging the highway and to facilitate the passage of cables, pipes, and other materials beneath the road. The primary purpose of these structures is to contribute to the functionality of the highway, extend its economic life, and ensure safe traffic flow. Culverts, which come in different types depending on their intended use and location, primarily serve to provide transverse transitions from one side of the highway to the other. Culvert types include bridge culverts, box culverts, arched culverts, deck culverts (standard bridges), and pipe culverts. Hydraulic capacity is a fundamental engineering parameter in the design of culverts that serve hydraulic drainage functions. When designed in accordance with appropriate engineering principles, these structures not only provide water flow but can also function as underpasses serving vehicle and pedestrian traffic. Different building materials are used in the construction of culverts. Historically, culverts constructed with stone walls and clay-based materials were common, but today, reinforced concrete culverts are particularly preferred. Additionally, plastic or steel culverts of various sizes and geometries are also used in modern applications. For drainage structures to function effectively, they must be selected according to their function, constructed in technically suitable locations and with adequate dimensions, and maintained at regular intervals. Floods and inundations that have occurred in Türkiye in recent years have caused collapses at the approaches to culverts and bridges on many provincial and state highways. Therefore, this study aims to investigate the mechanisms of highway collapse in culvert sections during floods and inundations occurring during rainfall periods. Keywords: Culvert, Drainage, Flood