What does the culvert length mean?

Culvert length refers to the total length between the outer edges of the walls at both ends of the culvert entrance and exit, including settlement joints and joints, and the calculation accuracy is 0.01m.

Culvert length is determined according to subgrade width (including curve subgrade widening and route spacing widening, etc.). ), embankment slope ratio, culvert top fill height, inlet and outlet trench bottom elevation, wing wall shape at both ends and skew influence. When calculating, firstly, calculate the length according to the shape of the original trench bed in the upstream and downstream, the height difference between the shoulder or the road surface and the trench bed, and then check the elevation of the proposed entrance and exit trench bottom and calculate the culvert length according to the actual terrain. Is there any hanging or deep excavation at the bottom of culvert? Repeated trial and error until satisfactory elevation of inlet and outlet trench bottom and culvert length are obtained. You can also draw the toe line of the outlet embankment slope on the route cross-section map, determine the entrance elevation and calculate the culvert length.