Cross Section¶
The cross section, along with widening and superelevation, are important for determining the design of both road bodies and intersections.
In Gemini Terrain you can describe the cross section (road body) with three different methods:
- Parametric
- Manual
- 3D lines
When designing roads in Gemini Terrain, it is common to use the parametric method. This method uses the road library based on handbook N100.
In the properties dialog for SFI-model, you find the methods under the Road tab. At the top of the dialog, you find the method for parametric road.
In parametric road, you describe the theoretical cross section with parameters. You can add these manually to the road project, but normally you start from a template (Use template...). Templates have been created for all road classes in N100.
You can change the road parameters freely along the road alignment. Furthermore, you can dimension widening and superelevation automatically according to requirements in N100, which is described in more detail later in this section.
The table below shows all parameters with some of their properties. Units for values or positive direction for slopes are indicated. Whether the value changes linearly or is constant between values is also specified.
Parameters for road surface¶
| Parameter name | New code | Unit | Note | Intermediate values |
|---|---|---|---|---|
| Median 1 width | 0010 | Meter | Interpolated | |
| Median 1 slope | 0011 | Decimal down | Interpolated | |
| Median 2 width | 0020 | Meter | Interpolated | |
| Median 2 slope | 0021 | Decimal down | Interpolated | |
| Median 3 width | 0030 | Meter | Interpolated | |
| Median 3 slope | 0031 | Decimal down | Interpolated | |
| Median 4 width | 0040 | Meter | Interpolated | |
| Median 4 slope | 0041 | Decimal down | Interpolated | |
| Median 5 width | 0050 | Meter | Interpolated | |
| Median 5 slope | 0051 | Decimal down | Interpolated | |
| Median 6 width | 0060 | Meter | Interpolated | |
| Median 6 slope | 0061 | Decimal down | Interpolated | |
| Median 7 width | 0070 | Meter | Interpolated | |
| Median 7 slope | 0071 | Decimal down | Interpolated | |
| Median 8 width | 0080 | Meter | Interpolated | |
| Median 8 slope | 0081 | Decimal down | Interpolated | |
| Median 9 width | 0090 | Meter | Interpolated | |
| Median 9 slope | 0091 | Decimal down | Interpolated | |
| Carriageway 1, width | 0110 | Meter | Interpolated | |
| Carriageway 1, slope | 0111 | Decimal down | Interpolated | |
| Carriageway 2, width (widening) | 0120 | Meter | calculated when generating widening from road class | Interpolated |
| Carriageway 2, slope | 0121 | Decimal down | Interpolated | |
| Carriageway 3, width | 0130 | Meter | Interpolated | |
| Carriageway 3, slope | 0131 | Decimal down | Interpolated | |
| Carriageway 4, width (widening) | 0140 | Meter | calculated when generating widening from road class with four lanes | Interpolated |
| Carriageway 4, slope | 0141 | Decimal down | Interpolated | |
| Carriageway 5, width | 0150 | Meter | Interpolated | |
| Carriageway 5, slope | 0151 | Decimal down | Interpolated | |
| Carriageway 6, width | 0160 | Meter | Interpolated | |
| Carriageway 6, slope | 0161 | Decimal down | Interpolated | |
| Carriageway 7, width | 0170 | Meter | e.g. emergency lane | Interpolated |
| Carriageway 7, slope | 0171 | Decimal down | Interpolated | |
| Carriageway 8, width | 0180 | Meter | e.g. emergency bay / bus bay | Interpolated |
| Carriageway 8, slope | 0181 | Decimal down | Interpolated | |
| Carriageway 9, width | 0190 | Meter | Interpolated | |
| Carriageway 9, slope | 0191 | Decimal down | Interpolated | |
| Shoulder 1, width | 0210 | Meter | Interpolated | |
| Shoulder 1, slope | 0211 | Decimal down | Interpolated | |
| Shoulder, slope (relative to carriageway) | 0212 | Decimal down | applies to all shoulder surfaces | Interpolated |
| Shoulder 2, width | 0220 | Meter | Interpolated | |
| Shoulder 2, slope | 0221 | Decimal down | Interpolated | |
| Shoulder 3, width (barrier extension) | 0230 | Meter | added when fill height, height difference between road edge and fill toe, is greater than value given in parameter 0790 boundary low/high fill | Interpolated |
| Shoulder 3, slope | 0231 | Decimal down | Interpolated | |
| Shoulder 4, width | 0240 | Meter | e.g. curb | Interpolated |
| Shoulder 4, slope | 0241 | Decimal down | Interpolated | |
| Shoulder 5, width | 0250 | Meter | Interpolated | |
| Shoulder 5, slope | 0251 | Decimal down | Interpolated | |
| Shoulder 6, width | 0260 | Meter | Interpolated | |
| Shoulder 6, slope | 0261 | Decimal down | Interpolated | |
| Shoulder 7, width | 0270 | Meter | Interpolated | |
| Shoulder 7, slope | 0271 | Decimal down | Interpolated | |
| Shoulder 8, width | 0280 | Meter | Interpolated | |
| Shoulder 8, slope | 0281 | Decimal down | Interpolated | |
| Shoulder 9, width | 0290 | Meter | Interpolated | |
| Shoulder 9, slope | 0291 | Decimal down | Interpolated | |
| Additional surface 1, width (road-sidewalk separator 1) | 0310 | Meter | Interpolated | |
| Additional surface 1, slope (road-sidewalk separator 1) | 0311 | Decimal down | Interpolated | |
| Additional surface 2, width (road-sidewalk separator 2) | 0320 | Meter | Interpolated | |
| Additional surface 2, slope (road-sidewalk separator 2) | 0321 | Decimal down | Interpolated | |
| Additional surface 3, width (road-sidewalk separator 3) | 0330 | Meter | Interpolated | |
| Additional surface 3, slope (road-sidewalk separator 3) | 0331 | Decimal down | Interpolated | |
| Additional surface 4, width | 0340 | Meter | Interpolated | |
| Additional surface 4, slope | 0341 | Decimal down | Interpolated | |
| Additional surface 5, width (sidewalk inner shoulder) | 0350 | Meter | Interpolated | |
| Additional surface 5, slope (sidewalk inner shoulder) | 0351 | Decimal down | Interpolated | |
| Additional surface 6, width (sidewalk) | 0360 | Meter | Interpolated | |
| Additional surface 6, slope (sidewalk) | 0361 | Decimal down | Interpolated | |
| Additional surface 7, width (sidewalk outer shoulder) | 0370 | Meter | Interpolated | |
| Additional surface 7, slope (sidewalk outer shoulder) | 0371 | Decimal down | Interpolated | |
| Additional surface 8, width | 0380 | Meter | Interpolated | |
| Additional surface 8, slope | 0381 | Decimal down | Interpolated | |
| Additional surface 9, width | 0390 | Meter | Interpolated | |
| Additional surface 9, slope | 0391 | Decimal down | Interpolated | |
| Ditch 1, width | 0410 | Meter | Interpolated | |
| Ditch 1, slope | 0411 | Decimal down | Interpolated | |
| Ditch 2, width | 0420 | Meter | Interpolated | |
| Ditch 2, slope | 0421 | Decimal down | Interpolated | |
| Ditch 3, width | 0430 | Meter | Interpolated | |
| Ditch 3, slope | 0431 | Decimal down | Interpolated | |
| Ditch 4, width | 0440 | Meter | Interpolated | |
| Ditch 4, slope | 0441 | Decimal down | Interpolated | |
| Ditch 5, width | 0450 | Meter | Interpolated | |
| Ditch 5, slope | 0451 | Decimal down | Interpolated | |
| Ditch 6, width | 0460 | Meter | Interpolated | |
| Ditch 6, slope | 0461 | Decimal down | Interpolated | |
| Ditch 7, width | 0470 | Meter | Interpolated | |
| Ditch 7, slope | 0471 | Decimal down | Interpolated | |
| Ditch 8, width | 0480 | Meter | Interpolated | |
| Ditch 8, slope | 0481 | Decimal down | Interpolated | |
| Ditch 9, width | 0490 | Meter | Interpolated | |
| Ditch 9, slope | 0491 | Decimal down | Interpolated | |
| Rock cut 1, width | 0510 | Meter | Interpolated | |
| Rock cut 1, slope | 0511 | Decimal down | Interpolated | |
| Rock cut 2, width | 0520 | Meter | Interpolated | |
| Rock cut 2, slope | 0521 | Decimal up | Interpolated | |
| Rock cut 3, width | 0530 | Meter | Interpolated | |
| Rock cut 3, slope | 0531 | Decimal | Interpolated | |
| Rock cut 4, width | 0540 | Meter | Interpolated | |
| Rock cut 4, slope | 0541 | Decimal down | Interpolated | |
| Rock cut 5, width | 0550 | Meter | Interpolated | |
| Rock cut 5, slope | 0551 | Decimal up | Interpolated | |
| Rock cut 6, width | 0560 | Meter | Interpolated | |
| Rock cut 6, slope | 0561 | Decimal | Interpolated | |
| Rock cut 7, width | 0570 | Meter | Interpolated | |
| Rock cut 7, slope | 0571 | Decimal down | Interpolated | |
| Rock cut 8, width | 0580 | Meter | Interpolated | |
| Rock cut 8, slope | 0581 | Decimal up | Interpolated | |
| Rock bench, width | 0590 | Meter | Constant | |
| Rock bench addition, percent | 0591 | No unit | Constant | |
| Soil cut 1, width | 0610 | Meter | Interpolated | |
| Soil cut 1, slope | 0611 | Decimal up | Interpolated | |
| Soil cut 2, width | 0620 | Meter | Interpolated | |
| Soil cut 2, slope | 0621 | Decimal up | Interpolated | |
| Soil cut 3, width | 0630 | Meter | Interpolated | |
| Soil cut 3, slope | 0631 | Decimal up | Interpolated | |
| Soil cut 4, width | 0640 | Meter | Interpolated | |
| Soil cut 4, slope | 0641 | Decimal up | Interpolated | |
| Soil cut 5, width | 0650 | Meter | Interpolated | |
| Soil cut 5, slope | 0651 | Decimal up | Interpolated | |
| Soil cut 6, width | 0660 | Meter | Interpolated | |
| Soil cut 6, slope | 0661 | Decimal up | Interpolated | |
| Soil cut 7, width | 0670 | Meter | Interpolated | |
| Soil cut 7, slope | 0671 | Decimal up | Interpolated | |
| Soil cut 8, width | 0680 | Meter | Interpolated | |
| Soil cut 8, slope | 0681 | Decimal up | Interpolated | |
| Fill 1, width | 0710 | Meter | Interpolated | |
| Fill 1, slope (low) | 0711 | Decimal down | Interpolated | |
| Fill 2, width | 0720 | Meter | Interpolated | |
| Fill 2, slope | 0721 | Decimal down | Interpolated | |
| Fill 3, width | 0730 | Meter | Interpolated | |
| Fill 3, slope | 0731 | Decimal down | Interpolated | |
| Fill 4, width | 0740 | Meter | Interpolated | |
| Fill 4, slope (low) | 0741 | Decimal down | Interpolated | |
| Fill 5, width | 0750 | Meter | Interpolated | |
| Fill 5, slope | 0751 | Decimal down | Interpolated | |
| Fill 6, width | 0760 | Meter | Interpolated | |
| Fill 6, slope | 0761 | Decimal down | Interpolated | |
| Fill 7, width | 0770 | Meter | Interpolated | |
| Fill 7, slope (low) | 0771 | Decimal down | Interpolated | |
| Fill 8, width | 0780 | Meter | Interpolated | |
| Fill 8, slope | 0781 | Decimal down | Interpolated | |
| Boundary low/high fill, height | 0790 | Meter | Constant | |
| Fill 1, slope (high) | 0791 | Decimal down | Interpolated |
Parameters for pavement¶
| Parameter name | New code | Unit | Note | Intermediate values |
|---|---|---|---|---|
| Surface course, carriageway | 1111 | Meter | Constant | |
| Surface course, shoulder | 1112 | Meter | Constant | |
| Binder course 1 | 1121 | Meter | Constant | |
| Binder course 2 | 1131 | Meter | Constant | |
| Base course 1 | 1141 | Meter | Constant | |
| Base course 2 | 1151 | Meter | Constant | |
| Subbase layer 1 soil | 1161 | Meter | Constant | |
| Subbase layer 1 rock | 1162 | Meter | Constant | |
| Subbase layer 2 | 1171 | Meter | Constant | |
| Filter/frost protection layer | 1172 | Meter | Constant | |
| Surface course, additional surfaces 6 (sidewalk) | 1311 | Meter | Constant | |
| Surface course, additional surfaces 5,7 (sidewalk shoulder) | 1312 | Meter | Constant | |
| Binder course 1, additional surfaces 5-7 (sidewalk) | 1321 | Meter | Constant | |
| Base course 1, additional surfaces 5-7 (sidewalk) | 1341 | Meter | Constant | |
| Subbase layer 1 soil, additional surfaces 5-7 | 1361 | Meter | Constant | |
| Subbase layer 1 rock, additional surfaces 5-7 | 1362 | Meter | Constant | |
| Filter/frost protection layer, additional surfaces 5-7 | 1381 | Meter | Constant | |
| Stone pitching | 1910 | Meter | On outermost carriageway or shoulder surface | Constant |
| Excavation slope | 1920 | Meter | Constant |
Parameters for subgrade¶
| Parameter name | New code | Unit | Note | Intermediate values |
|---|---|---|---|---|
| Deep excavation | 9101 | Meter | Constant | |
| Deep excavation cross fall | 9102 | Decimal down | Interpolated | |
| Cross fall trough bottom | 9201 | Decimal down | Interpolated |
Handbook N100 provides, as previously mentioned, dimensions for the cross section for each design class.
The road design library in Gemini Terrain automatically retrieves values according to the class for the following parameters:
- Median
- Median shoulder
- Carriageway 1
- Carriageway 2
- Shoulder
and calculates the values for:
- Superelevation
- Widening
Cross Section¶
The values are placed in these road parameters:
- Code 0010 - Median 1, width
- Code 0040 - Median 4, width (shoulder)
- Code 0110 - Carriageway 1, width
- Code 0130 - Carriageway 3, width
- Code 0210 - Shoulder 1, width
Superelevation/Cross Fall¶
Data for the following road parameter is calculated:
- Code 0111 - Carriageway 1, slope (superelevation/cross fall)
The purpose of superelevation is to counteract lateral forces, ensure water drainage (minimum cross fall dH=3cm per meter width, 3%) and provide good driving comfort.
A = Crown slope, B = One-way slope
Superelevation buildup must not happen too quickly. This will feel like a jolt in the vehicle. Therefore, there are requirements for the length of the buildup. The clothoid is well-suited for superelevation buildup due to gradual and linear change of curvature and thus centrifugal force.
The selection for superelevation automatically calculates superelevation diagrams according to the given design class.
Widening¶
Data for the following road parameters is calculated:
- Code 0120 - Carriageway 2, width (widening for carriageway 1)
- Code 0140 - Carriageway 4, width (widening for carriageway 3)