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Pipeline Design: Exact 3D Design

Exact 3D Design

Exact 3D design is the standard method in Gemini Terrain.

With this method, you design manholes and pipes with precise placement in the terrain by entering 3D lines directly into the terrain model with the desired offset values.

This method provides an accurate 3D model and stakeout data for all manholes and pipes. Automatic trench construction is also enabled for this method.

Instructions

  1. Select the Data linked to line definition... icon in the Planning, Design, and Execution toolset.
  2. Select the desired SFI model and click OK (the SFI model is created as described in the previous section).
  3. Create a data type for the controlling pipe (usually the lowest one).
  4. Check CL to indicate that this will be used as the line definition.
  5. Place manholes and bends in the map.
  6. Edit or supplement properties directly in the list.
  7. Generate a long section, optionally with an advanced section if the trench is in a road or intersection.
  8. Check and adjust levels to ensure slope and cover requirements are met.
  9. Switch to plan view.
  10. Create the remaining data types and repeat steps 5–8 for these.

As described in the procedure, you place manholes and bends in plan view. Then, check slope, cover, and similar in the long section. Any adjustments to levels and the addition of vertical bends or break points are also best done here. If the alignment needs to be moved horizontally, return to plan view. After some back and forth between plan view and long section, the trench alignment is determined.

Normally, there are several pipes in the trench, so you must select one pipe as CL. The line definition is then continuously updated with the geometry of this pipe. This results in a line definition with straight segments, which can cause breaks in the line definition and problems with the 3D model if cross-sections intersect. To solve this, you can smooth the line definition. When smoothing is selected, the program automatically adds rounding at break points. The size of the rounding is calculated based on the specified corridor width. This provides a better 3D trench, especially in areas with several manholes.

Below, some of the steps in the procedure are described in more detail.

Creating Data Types

A pipe run may have several trench cross-sections. Below is a typical trench cross-section with three pipes.

Figure: VL = Water pipe, SP = Wastewater, OV = Stormwater

You must decide which pipe in the trench to start with and set this as the line definition (CL) for the trench. Usually, you start with the lowest pipe.

Create new data types by selecting New... with the right mouse button in the list for Data linked to line definition.

The following data types are relevant for pipeline design:

  • Stormwater data
  • Wastewater data
  • Water data
  • Pump main
  • Drainage pipe
  • Stormwater2 data
  • Wastewater2 data
  • Water2 data
  • Pump main2
  • Stormwater branch
  • Wastewater branch
  • Water branch
  • Pump main branch
  • Drainage branch
  • Pipeline annotation

In addition to geometry, the data types also have the following properties:

  • Level 1 / Level 2
    These are the pipe levels (absolute elevation) in and out of the manhole. Both must be entered even if they are the same. For wastewater and stormwater, enter the level for the bottom inside the pipe; for water, enter the top outside the pipe.

  • M.Type – Manhole type
    You can choose between three manhole types:

  • Cylinder
  • Cylinder with concentric cone

  • Cylinder with eccentric cone

  • M.Dim – Manhole dimension
    The manhole diameter is given in meters. The manhole symbol will not be drawn when the dimension is set to 0. Used, for example, when drawing alignment points in the pipe run.

  • M.Thick – Manhole thickness
    The thickness can be positive, negative, or zero.

  • Positive: Manhole diameter is interpreted as inner diameter, thickness is added to create the outer wall.
  • Negative: Manhole diameter is interpreted as outer diameter, thickness is added to create an inner wall.
  • Zero: Only one wall is drawn (as before).

!!! note The manhole cover will have an increased radius if the thickness is positive. Note that circle symbols in 2D will also expand when positive.

  • M.CoverDim – Manhole cover dimension
  • M.ConeH – Manhole cone height
  • M.AdjustRingH – Manhole adjustment ring height
  • M.OffBottom – Manhole offset bottom

  • P.Dim – Pipe dimension
    Pipe dimension is given in meters. The pipe will not be drawn when the dimension is set to 0 (applies to pipe into manhole). Used, for example, if a pipe has a gap in the trench.

  • P.Thick – Pipe thickness
    If the reference line is bottom or top inside, the diameter is given for the inside.
    If the reference line is bottom or top outside, the diameter is given for the outside.

Thickness is also considered when building the trench. The parameters refer to the outer cylinder.

  • P.Type – Pipe type
  • P.Mat – Pipe material

  • P.Bend – Pipe bend
    The conditions for drawing a bend at a point are that Level 1 and Level 2 are equal and the manhole dimension is 0.

  • Slope
    The program calculates the slope of the pipes from their levels.

  • Deflection angle

Placing Manholes and Bends in the Map

Available editing functions can be found by pointing in the map and right-clicking:

Function Key combination
Finish and save Enter
Insert point Ins
Move point M
Move presentation point O
Move text T
Previous data type P
Next data type N
Delete selected point Backspace
Guide geometry
Move dialog box to mouse position
Cancel and exit Esc

Place manholes and bends (break points) using Insert point. When this is active, you can freely select system points in the map.

Tip

Guide options for dynamic lines can be a useful tool when placing system points. Here you can enter relevant deflection angles and distances. Guide options for dynamic lines are found on the status bar.

Generate Long Section

Use the standard command to generate a long section for the pipe run. Select the chaindata (.sfi) command and choose Generate long section* from the context menu.

In many cases, the trench is located in both "virgin" terrain and in a road.

In such cases, start with a completed road calculation that determines the placement of manholes both in elevation and plan.

It is therefore important that the road body is included in the drawing and that the terrain layer is calculated with Perform intervention enabled (option in Drawing Settings).

You must also check Include 3D objects when generating the profile.

Checking Levels Against Slope and Cover

In the long section, you can extract a mass calculation that gives you various depth intervals. This is useful for marking where the cover is less than the minimum requirement.

The mass types for the different intervals are found under the mass types tab in the SFI properties dialog. For example, retrieve mass types with IDs 49–57.

This mass calculation assumes that a theoretical layer for the trench bottom has been created.

Use the Add... function with the right mouse button in the horizontal list field and select the theoretical layer for the trench bottom. You will be asked whether you want to retrieve the elevations directly from the line definition; alternatively, you must enter them manually by snapping in the long section.

You can also solve this by creating a separate mass type called Cover. Select calculation type Area and enter the max. and min. depth for the approved laying area.

Pipe Annotations

There is also a data type Pipeline annotation that provides automatic labeling of the pipes. This writes the properties Pipe type, Pipe dimension, and Pipe material.

Normally, you also add stationing with the general Line definition annotation command in the toolbox.

Pen tables control the appearance on screen and in print (plot). This applies to both map data and designed data such as pipelines. The installation includes a pen table named TER, which the program copies to the project directory when you create a new project. All pens from 1–255 are defined with color and thickness.

Pipeline data has presentation rules for plan and profile views. The pen selections require that the TER pen table is active. You can change the presentation setup as follows:

  1. Select Presentation for line definition data from the Format menu.
  2. Select the desired data type and click Edit...

Special Case

You may encounter situations where none of the pipes follow the entire trench.

In this case, you must either split the trench into several SFI models or create a line definition independent of the pipes. For the latter solution, use the line definition command directly to construct an independent line definition, for example, by snapping to manholes along the entire run. In this case, do not check CL for any of the pipes.