Mastering AutoCAD® Civil 3D® 2010

Chapter 11

Easy Does It: Basic Corridors

The corridor object is a three-dimensional road model that combines the horizontal geometry of

an alignment, the vertical geometry of a profile, and the cross-sectional geometry of an a ssembly.

Corridors range from extremely simple roads to complicated highways and interchanges. This

chapter focuses on building several simple corridors that can be used to model and design roads,

channels, and trenches.

By the end of this chapter, you’ll learn to:

◆ Build a single baseline corridor from an alignment, profile, and assembly

◆ Create a corridor surface

◆ Add an automatic boundary to a corridor surface

Understanding Corridors

It its simplest form, a corridor is a three-dimensional combination of an alignment, a profile, and

an assembly (see Figure 11.1).

You can also build corridors with additional combinations of alignments, profiles, and assem-

blies to make complicated intersections, interchanges, and branching streams (see Figure 11.2).

The horizontal properties of the alignment, the vertical properties of the profile, and the

cross-sectional properties of the assembly are merged toget her to form a dynamic model that

can be used to build surfaces, sample cross sections, and much more.

Most commonly, corridors are thought of as being used to model roads, but they can also be

adapted to model berms, streams, lagoons, trails, and even parking lots (see Figure 11.3).

Creating a Simple Road Corridor

The first ingredient in any corridor is an alignment. This alignment is referred to as a baseline.A

baseline requires a corresponding profile and an assembly. A corridor can have multiple base-

lines, and a baseline can be divided into regions. You’ll see how regions are used a little later in

this chapter. (Corridors with multiple baselines are discussed in Chapter 12, ‘‘The Road Ahead:

Advanced Corridors.’’)

When you create and iterate a design, you may be tempted to use its default name, such as

Alignment-64 or Basic Lane-(3)(3), instead of a much more meaningful name. Before building a

corridor, even a simple corridor, it is important to make sure your alignments, profiles, assemblies,

and subassemblies have good names. If you get into the habit of giving your objects significant

and meaningful names — e ven for the simplest corridor — you w ill be rewarded when you build

larger corridors (see Figure 11.4).

398 CHAPTER 11 EASY DOES IT: BASIC CORRIDORS

Figure 11.1

A simple corridor

Figure 11.2

An intersection modeled

with a corridor

Figure 11.3

Acomplexstream

modeled with a corridor

CREATING A SIMPLE ROAD CORRIDOR 399

Figure 11.4

Check the names

of your alignments,

profiles, assemblies, and

subassemblies

This exercise gives you hands-on experience in building a corridor model from an alignment, a

profile, and an assembly:

1. Open the Simple Corridor.dwg file, which you can download from www.sybex.com/go/

masteringcivil3d2010. Note that t he drawing has an alignment, a profile view with two

profiles, and an assembly, as well as an existing ground surface.

2. Change to the Home tab and select Corridor  Create Simple Corridor from the Create

Design panel. The Create Simple Corridor dialog opens.

3. In the Name text box, give your corridor a meaningful name, such as Project Road. Keep

the default values for Corridor Style and Corridor Layer (see Figure 11.5).

Figure 11.5

Change the corridor

name to something

meaningful for easy

bookkeeping

4. Click OK to dismiss the dialog.

400 CHAPTER 11 EASY DOES IT: BASIC CORRIDORS

5. At the Select baseline alignment <or press enter key to select from list>: prompt,

pick the alignment in the drawing. Alternatively, you could press

5

and select your align-

ment from a list.

6. At the Select a profile <or press enter key to select from list>: prompt, pick the

Finished Ground profile (the profile with labels) in the drawing. Alternatively, you could

press

5

and select your profile from a list.

7. At the Select an assembly <or press enter key to select from list>: prompt, pick the

vertical line of the assembly in the drawing. Alternatively, you could press

5

and select

your assembly from a list.

8. The program will process and build the corridor. Dismiss the Panorama if it appears over

the road centerline alignment as shown in Figure 11.6.

Figure 11.6

The completed simple

corridor

Utilities for Viewing Your Corridor

Once your corridor is built, chances are you will want to examine the corridor in section view

and use 3D to view the model and check for problems. For a station-by-station look at a corridor,

pick the corridor and choose Corridor Section Editor from the Modify panel. The Section Editor

contextual tab opens (see Figure 11.7).

Figure 11.7

The Section Editor

contextual tab with

the Corridor Edit Tools

panel pinned open

The Station Selection panel on the Section Editor contextual tab allows you to move forward

and backward through your corridor to see what each section looks like. There are also options