How to put the eight-character wall of culvert with surveyor software

1. First, according to the drawing size, extend the inner wall line of the culvert to both sides and find the end point of the figure of eight.

2. Secondly, connect two extension points and extend outward to the edge of the figure 8. This dimension is shown on the drawing.

3. Finally, determine the masonry height by measuring the elevation, and hang a diagonal line with the top of culvert plate according to the height.