Understanding simple difinition contour lines ₪ 3.3 Cross sections

# Understanding simple difinition contour lines ₪ 3.3 Cross sections

Cross  sections (cross-sections perpendicular to the project naxis) are used to calculate the following parameters:

₪  The position of the theoretical entry points of the earthworks
₪  The base of the project and its influence on the natural terrain
₪  Cubatures (volumes of cut and fill ).

The left lane must then be on the left side of the profile.
We start by drawing the natural terrain from a horizontal reference plane which is not necessarily that of the   longitudinal profile, so as to obtain the cross section at the maximum scale on the chosen format.

The scale of representation is of the order of 1/100 to 1/200  (up to 1/50 for the narrowest routes). There is no different scale in abscissa and in ordinate so as to be able to measure directly on the graph legths in all directions or surfaces

The abscissa of each point of the natural terrain (or of the project) is located in relation to the axis of the cross section (therefore negative on the laft and positive on the right), the ordinate is always the altitude of the point.
The standard template for the project is then superimposed on it (width of roadway, shoulders, ditches and embankment slopes ) from the axis point whose altitude has been determined on the longitudinal profile

This... .

There are three types of cross sections (fig. 10.13.): embankment profiles , cuttings or mixed profiles .

It should be noted that the presence of the ditch on these different types of profiles is only necessary in the event of the impossibility of natural water flow. For example, compare the fill profile and the mixed profile .

Cross section principle
Example of a Computerized Cross Section