In this article I want to return to a discussion of the work of the CLSA Central Valley Chapter Construction Committee on standards for the use of digital design files for heavy construction projects. In this article we will begin a review of the standard being developed by the committee for the transmittal of digital data from the design team to the contractor or construction management team. This standard contains three (3) key elements:
- A computer file system folder structure definition for digital
transmittal packages. - Standard files and file content.
- CAD standards for drawing files included as part of the transmittal.
The folder structure contains 5 top-level folders and a 2 files. The folders are:
- Corridors
- Drainage
- Structures
- Surfaces
- Survey Control
Each folder contains sub-folders, drawing files, and other files related to the design of the project improvements. These five (5) top-level folders are described briefly below:
Corridors: Contains drawing files and text files that define horizontal alignments and vertical profiles for route corridors. A route corridor could be for a road, a railroad, a canal, a pipeline or any other long linear site improvement. Files for individual corridors on the project sites are contained in sub-folders of this top-level folder.
Drainage: Contains drawing files and text files that define horizontal alignments and vertical profiles for linear drainage features. It also contains drawing files and text files that define the 2D (planimetric) linework and 3D breaklines for non-linear drainage features like detention basins, ponds, or artificial stream beds and non-uniform drainage swales.
Structures: Contains drawing files and text files that define the footprint and important features (for example: column lines) of structures to be built on the project site.
Surfaces: Contains drawing files and text files to represent different construction surfaces for the project site. These surfaces could include existing conditions, rough grade, intermediate grade, and finish grade. Drawings may contain TIN lines, points, contours, contour labels, and spot elevations. Cross-sections and profile view, volume calculations, and other site grading information, may also be provided in this folder.
Survey Control: Contains drawing files and text files with information on survey control provided for use during layout and construction.
The two (2) files contained in the top level folder are the Master Drawing List and the Master Metadata File. The master drawing list provides basic information on all drawings contained in the transmittal package. The master metadata file contains a set of key-value pairs of metadata about the transmittal package and its contents.
In our next article we will discuss the corridor folder in more detail and will look at the standards for the contents and formatting of corridor drawing files contained in the transmittal package.
