Elevation plan
The height plan (also longitudinal section , longitudinal profile or in Austria longitudinal section ) is part of the design and implementation documents in road and rail construction. It shows a vertical section along a route , the axis usually serves as the reference line .
In order to be able to clearly show longitudinal inclinations, inclination changes and small differences in height, the elevation plan is drawn distorted or exaggerated. This means that the height of the scale is ten times larger than the length of the scale. Common scales (length to height) are 1: 500 to 1:50 or 1: 1000 to 1: 100.
In the elevation plan, in addition to the height of the route (the so-called gradient ) and the contour line of the terrain , the incline band (also called the slope band) and the dome or tub fillets are shown. Furthermore, the profile plan includes the stationing of the route, structures and, if necessary, the components of the road drainage (shafts and pipes). Curvature belt , bank belt and drainage belt are also assigned .
Design elements
The following design elements are used for the gradient in the profile plan:
- Pitch
- Rounding of the crest
- Tub fillet
Pitch
Extra-urban roads
In order to keep the moving earth mass as low as possible, the gradient should adapt to the terrain as well as possible. However, certain limit values must also be observed, which depend on the design class (EKL Landstraßen, EKA Autobahn). In the case of large longitudinal inclines, drainage is ensured, but the impairment of long uphill and downhill stretches on traffic safety and the flow of traffic increases significantly.
The following table provides the permissible longitudinal gradients depending on the country road design class (EKL) and the motorway design class (EKA).
| Country road | Highway | ||
|---|---|---|---|
| Design class | max s [%] | Design class | max s [%] |
| EKL 1 | 4.5 | EKA 1A | 4.0 |
| EKL 2 | 5.5 | EKA 1B | 4.5 |
| EKL 3 | 6.5 | EKA 2 | 4.5 |
| EKL 4 | 8.0 | EKA 3 | 6.0 |
Urban streets
According to the guidelines for the construction of city streets, there are no design classes for urban streets. The maximum longitudinal inclinations depend on the permissible speeds (V perm ).
At V perm = 50 km / h the result is max s = 8.0 (12.0)%; at V perm = 70 km / h the result is max s = 6.0 (8.0)% (values in brackets are exceptions).
Dome and tub rounding
Extra-urban roads
Because the gradient is adapted to the terrain, the gradient forms a trough in the valleys and a crest on the hilltops . Since a sudden change from incline to incline or vice versa cannot be implemented in terms of driving dynamics, the tub or crest must be rounded. The vertical distance between the tangent intersection and the gradient fillet is known as the arc stitch . The length of a fillet is obtained from the double tangent length t . A distinction is made between a change in inclination and a change in inclination . A change in incline occurs when the incline of a road changes (e.g. from an incline with 4% to an incline with 3%). A change in incline refers to a complete change in the longitudinal incline (e.g. from an incline with 4% to a descent with 4%).
The following table lists the tip and trough radius recommended according to RAL and the minimum lengths of the tangents.
| Design class | Tip radius
H k [m] |
Tub radius
H w [m] |
Tangent length
T [m] |
|---|---|---|---|
| EKL 1 | ≥ 8000 | ≥ 4000 | 100 |
| EKL 2 | ≥ 6000 | ≥ 3500 | 85 |
| EKL 3 | ≥ 5000 | ≥ 3000 | 70 |
| EKL 4 | ≥ 3000 | ≥ 2000 | 55 |
Regardless of this, a minimum radius must be observed to ensure stopping and overtaking visibility and the frictional connection.
Urban streets
In urban roads, the driving dynamics generally play no role, so that predominantly the drivability has to be taken into account. In order to prevent vehicles from touching down, the following minimum rounding must be observed on city streets:
| Attached city streets | City streets without cultivation with v perm = 50 km / h |
City streets without cultivation with v perm = 70 km / h |
|
|---|---|---|---|
| Rounding of the crest | 250 m | 900 m | 2200 m |
| Tub fillet | 150 m | 500 m | 1200 m |
history
With the introduction of the Railway Construction and Operating Regulations in May 1967, the formerly valid regulation of inserting a horizontal or slightly inclined intermediate section between two opposing inclines was repealed.
literature
- Wolfgang Pietzsch, Günter Wolf: Street planning. 7th edition. Werner Engineer Texts, 2004, ISBN 3-8041-5003-9 .
- Renate Galla et al. a .: Expertise for draftsmen . BG Teubner Verlag, Leipzig 1999, ISBN 3-519-35608-2 , pp. 382 .
Individual evidence
- ↑ FGSV (Ed.): Guidelines for the layout of Stadtstraße (RASt) . Cologne 2006, p. 76 .
- ^ Heinz Delvendahl: The railway systems in the new railway building and operating regulations (EBO) . In: The Federal Railroad . tape 41 , no. 13/14 , 1967, ISSN 0007-5876 , pp. 453-460 .