Understanding Survey: 12D vs CAD
This article was crafted in collaboration with Steve Chambers, an esteemed Survey Manager. With close to two decades of experience in construction surveying, Steve now oversees the survey requirements across a diverse portfolio of projects. His fervent advocacy for the surveying profession and his expertise in the latest surveying technologies make him an invaluable contributor to the depth and quality of EngiMBA’s articles.
“Survey is one of the most important elements of building something in construction. In fact, I could be convinced that it is the most important.”
So why then is it that most Engineers can go almost their entire career without understanding how survey works?
In short, the answer to that question is, Good Surveyors. A good surveyor sorts it all out, handles the issues and gives us the nice report with all green numbers that we can put in our lot. If the numbers are green, we don’t need to know much more. However, the issue is that our industries competent Surveyors have produced incompetent Engineers because surveyors are often times too busy to take the time to mentor young engineers.
So the aim of this series of blogs, is to lay out some fundamentals of survey.
12D Model
1. Purpose:
12D Model is primarily used for road and drainage design in Australia and New Zealand.
It is a design package based on rigorous and accurate design and computation, it excels in handling complex tasks related to design creation, Survey reductions, triangulation, cut/fill volumes, and surface modeling.
Engineers and designers often use 12D for detailed road design and hydraulic analysis, pavement modeling and quantification of civil projects.
2. Capabilities:
Reduction and processing of survey information for the creation of digital elevation models: 12D can import raw survey data, reduce and manipulate it, and from this information, calculate catchments, runoff, and other hydrological parameters.
Parametric Design: It offers parametric modeling capabilities, making it suitable for intricate civil engineering projects.
12D is the market standard in Australia and New Zealand for road design and survey reduction. There are other Civil Design Packages and Separate survey reduction programs but 12d caters for both and is constantly improving the software to accept newer survey data and output more deliverables for the industry, Such as ADAC files.
3. Use Cases:
If your focus is on roads, 12D is a strong choice in Australia and New Zealand
It’s commonly used by designers who work on detailed road alignments and drainage systems.
4. Pros and Cons:
Pros: Advanced modeling, powerful triangulation, rigorous calculation methods and comprehensive road design features.
Cons: Some users find it less user-friendly.
AutoCAD
1. Purpose:
AutoCAD is a base program that branched into many fields, It can be used for Mechanical engineering, Archetecutual , residential design, especial effects and gaming modelling.
AutoCAD company achieves this by branching each of their products into specialised products they offer such as AutoCAD(Mechanical), Revit ( Architecture/Residential) , Civil 3D , Navisworks (structural) , Maya (film/CGI)
2. Capabilities:
Drafting and Detailing: AutoCAD excels in creating precise 2D and 3D drawings.
Reading Drawings: As a civil engineer in Australia, the drawings you read will often be produced by AutoCAD. But these are generally based off design models produced in 12d and with accompanying Cross sections and Long sections ( from 12d. Autocad is just used as a drafting packages to add notes, tables and present a cleaner product. While 12d is improving its drafting side, it doesn't do the greatest job for drafting of drawings. This cross over can cause issues in the design where some hatching is done in AutoCAD but not supplied in the 12d model provided to surveys and thus there is no digital data or Setout information through setout tables to actually quantify or build the works.
3. Use Cases:
AutoCAD is used by drafters, engineers, and architects for various tasks.
Most consultancies rely on AutoCAD for their drafting needs.
4. Pros and Cons:
Pros: Versatility, widespread adoption, and ease of use.
Cons: May not be tailored for the Australia and New Zealand market
