From Beginning to End-4D BIM for COSC 650

The Assignment was to arrive at 4D BIM for "The Church of Jesus Christ of Latter Day Saints at College Station, TX", which could then be used for visualization, construction sequencing, clash detection, site logistics etc. Overall, the project was broken into three stages:

Development of
1) 3D BIM
2) 4D BIM (attaching model with schedule)
3) Video

Stage 1: Development of 3D BIM

Extracting Information From CAD
  • Plans (.dwf) and Specification (.pdf) for the building were provided by the instructor.
  • First task was to eliminate extraneous information from the drawings so that they could be used in Revit for reference purpose easily (even though layers can be managed in Revit, pertaining to large number of layers involved I chose to extract the information in AutoCAD first and then import in Revit). For this .dwf was converted to .dwg using free converter available on internet. Once .dwg files were in hand, their units were adjusted and drawings manipulated to extract useful information (geometry and dimension) for creating model.
  • Once .dwg were ready, it was time to import them in Revit and build upon them.
File SetUp
  • Two models were created - One for architecture and structural part combined, and the Second for MEP. Using shared coordinates they were tied together (so that they fit snugly). Part of Architecture model was developed first to set the grid lines and other major references (walls) for MEP model. This model was linked with the MEP model. Copy and Monitor tools were used in the course of project to ensure model integrity at all times.
  • Revit file was setup using the default construction template_imperial. Important levels were assigned and the naming convention was chosen to reflect the original drawing. 
  • .dwg file was imported and grid line was drawn accordingly. 
Model Development
  • Model was developed in the order of Foundation > Walls > Windows & Doors > Truss & Rafters > Roof Covering > Steeple > Fascia and other decorative elements. The corresponding plans and elevations/sections were imported as and when required.
  • Existing wall types were modified into the required wall types. There were approximately 20 different wall types.
  • Window, door and column families were created separately.
  • Truss family were modified in Revit structure and then used.
  • Fascia and Steeple were made as component family but with fixed dimensions.
  • The Rostrum platform was created as an in-place family.

Stage 2: Development of 4D BIM

Activity based schedule to Deliverable based schedule
Before the model could be exported as .nwc files, the schedule had to be developed and the Revit model to be reworked upon. The construction schedule for the project was provided by the instructor but the problem was that it was activity based. For the schedule to be attached to model, it was converted to deliverable based schedule.
The approach used is explained below:
All the activities required for a particular deliverable were listed. For example, for walls, the activities ranged from erection of studs to painting. The activities available in the schedule, their sequence and the detail in the model decided which activities can be consolidated to yield a particular model element. Many reasonable and intelligent assumptions were made from time to time as well. The sequence of activities was modified to reflect the changes.

Reworking the Revit Model
Once the quantity of deliverable and the duration required to achieve that was known, that particular element was reworked to reflect the deliverable available for a single day ( For example, If roof covering is going to take 8 days then roof covering element was divided in 8 equal parts - so that each of those parts can be tied to a single day roof covering deliverable. The process was repeated for all the model elements.)

Exporting as .nwc file
Once the model and schedule was in place it was the time to export as .nwc files. To save time in Navisworks later, the elements were exported one by one (based on single day deliverable). While exporting from a particular view only the elements visible in the view are exported as .nwc. This feature proved to be very useful. The required elements were easily separated from rest of the model using hide tab in Revit. The exported .nwc files were later appended in the main .nwf file.

Attaching the schedule
The schedule was imported and each deliverable item was attached to model elements.

Stage 3: Development of Final Video

Adobe Premiere CS3 was used to develop final video.
Different viewpoints were created in Navisworks and construction simulation videos were exported as required. The main aim was to visualize the sequence rather than go into technical details of it. The video was created with this in mind.
Final Video is posted in previous blog.

>>>>>In Progress<<<<<

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