CAD CAD Specialist Civil and Infrastructure Design 1 — Questions and Answers
Question 1: Which AutoCAD Civil 3D object type is used to model the horizontal and vertical geometry of a road centerline?
- Alignment (Correct answer)
- Profile
- Corridor
- Grading Group
Correct answer: Alignment
An Alignment in Civil 3D defines the horizontal geometry of a road or route centerline.
Question 2: In Civil 3D, what term describes the cross-sectional shape applied repeatedly along an alignment to generate a 3D road model?
- Subassembly
- Assembly (Correct answer)
- Corridor
- Feature Line
Correct answer: Assembly
An Assembly is the full cross-section template (made of subassemblies) that is repeated along an alignment to build a corridor.
Question 3: What is the primary purpose of a grading group in AutoCAD Civil 3D?
- To define road lane widths
- To model site grading and earthwork volumes (Correct answer)
- To annotate contour elevations
- To create drainage pipe networks
Correct answer: To model site grading and earthwork volumes
Grading groups are used in Civil 3D to design site grading and calculate cut/fill earthwork volumes.
Question 4: Which coordinate system is most commonly specified in US civil engineering CAD projects for georeferencing drawings?
- WGS84
- State Plane Coordinate System (SPCS) (Correct answer)
- UTM Zone 10N
- ECEF
Correct answer: State Plane Coordinate System (SPCS)
The State Plane Coordinate System is the standard used in US civil engineering projects for local georeferencing accuracy.
Question 5: In a stormwater drainage design drawn in CAD, what term refers to the lowest point in a pipe or channel cross-section?
- Crown
- Invert (Correct answer)
- Soffit
- Flowline
Correct answer: Invert
The invert elevation is the elevation at the lowest interior point of a pipe or drainage structure.
Question 6: When creating a contour map in Civil 3D, which surface analysis method shows areas of equal elevation?
- Slope Arrows
- Watersheds
- Contours (Correct answer)
- Elevation Banding
Correct answer: Contours
Contours are lines connecting points of equal elevation and are the standard representation of terrain in civil CAD.
CAD CAD Specialist Civil and Infrastructure Design 1
Which AutoCAD Civil 3D object type is used to model the horizontal and vertical geometry of a road centerline?