What is the straight wall of circular pipe culvert?

Circular tube culvert is the most commonly used culvert structure type in rural highway subgrade drainage. It not only has good mechanical properties, but also has simple structure, convenient construction, short construction period and low cost. Reinforced concrete circular culvert is the most common one.

Circular pipe culvert consists of two parts: the hole body and the mouth of the cave. The tunnel body is the main body of the water passage, which is mainly composed of pipe body, foundation and joint. The entrance of the cave is the connection part of the tunnel body, subgrade and water flow, which mainly has two forms: splayed wall and straight wall.