Box Culvert is a reinforced concrete structure used as drainage under the road work. In other words, It is a small structure of less than 6m span between faces of abutments. On the other hand, minor bridge, if the length of the span is greater than 6m. It is a rigid frame structure and simple in construction. So, It is Suitable for non-perennial streams where scrub depth is not significant but the soil is weak. However, due to the strength of the concrete floor, water direction can be
changed when a large amount of water is expected.
Centerline Fixing. Firstly, The place where the culvert exists shall be located and the center line shall be marked with the help of Total station or electronic
