Pipe and Structure Rules (pipe network training)

The Network Parts List contains a column where you can define which rules should be used for the pipes and structures during the pipe network creation. When you create a pipe network in plan, Civil 3D assigns elevations for the structures and pipes automatically according to the specified rules. There are different rules for pipes and structures.

Pipe and structure rules help the designer to determine the pipes' and structures' preliminary elevation, the final elevation must be adjusted by the designer. The pipe and structure rules are very useful for sewer and stormwater pipe network design.

Pipe Rules

• Cover and Slope
• Cover only
• Length check
• Pipe to Pipe Match

Pipe Rule ‒ Cover and Slope

This rule works as follows:

1. Upstream invert is set based on the Cover at Structure

2. Downstream invert is set based on the Cover at Structure

3. Slope is checked

- Min Slope violation, Upstream invert is held => min Slope applied

- Max Slope violation, Pipe is flagged in view

4. Cover is checked along the entire length,1/3 ruled is applied

- Violation First 1/3, Downstream invert is held => Upstream is dropped

- Violation in Middle 1/3, Pipe is dropped to satisfy cover at low point => slope same

- Violation in Last 1/3, Upstream invert is held => Downstream invert is dropped

5. Slope is checked

- Min slope violation, Upstream invert is held => Downstream invert is dropped

- Max slope violation, Pipe is flagged in view

Steps 4 and 5 are repeated, until a solution is found.

Pipe Rule – Cover only

Upstream and downstream inverts are set based on the minimum cover along the entire length of the pipe.

Pipe Rule – Length Check

The length of the pipe is checked. There are three options to choose from:

1. Pipe only (without structure):

Lengths used for the rule are the 3D endpoint of the pipe to the endpoint of the pipe

B. Pipe with structure at one end:

Lengths used for the rule are the 3D centre of the structure to the endpoint of the pipe

1. Pipe with structure at each end:

Lengths used for the rule are the 3D centre of the structure to the centre of the structure

Pipe Rule – Pipe to Pipe Match

Connection between the two pipes is set based on:

• The match location of the two pipes (Crown, Centreline, Invert)
• The amount of vertical separation between the pipes

Structure Rules

• Pipe Drop across the Structure
• Sump Depth
• Max Pipe size check

Structure Rule – Pipe Drop Across the Structure

Checks the drop value between two pipes connected to a structure.

Structure Rule – Sump Depth

Checks the sump depth of the pipes connected to a structure.

Max Pipe Size Check

The size of pipes connected to a structure is checked.

Modify Rules

Rules can be opened either from the Toolspace – Settings – Pipe – Pipe Rule Set or from Toolspace – Settings – Structure – Structure Rule Set:

OR in the Pipe or Structure Properties window, Rules tab: