In today's fast-paced and cost-driven construction environment, tilt-up professionals constantly are seeking techniques to increase project efficiency, decrease overall cost, improve the project delivery schedule, and generate the best product possible. One technology available to assist in meeting these goals is Building Information Modeling (BIM)—a process for storing complete information about a building in a computer model. This information is used in all aspects of building production from design decision making, production of construction documents and construction planning, and in the end, to operation and management of the facility.
BIM techniques provide constant and immediate information on the project design, schedule, and cost that is reliable, integrated, and fully coordinated with the entire project team. It is designed to allow information to be handed from the design team (architects, surveyors, civil engineers, structural engineers, mechanical engineers, electrical engineers) to the contractor and subcontractors, and finally to the owner. Each team member can make their own changes and these revisions are tracked in a single source (the model). The result will significantly reduce misinformation or information loss that occurs when a new team takes “ownership” of the project. Also, this system can greatly decrease errors made by the design and construction team with the use of conflict detection. In this process, the computer informs team members about parts of the building that are in conflict with each other and provides a thorough detailed computer visualization of each section in relation to the total building. As always, error reduction equals cost savings for all members of a project.
Tilt-up professionals have realized the benefits BIM can bring to projects and have begun incorporating it into their work. Two of the main benefits that BIM offers a tilt-up project are accuracy and speed. However, since tilt-up projects require attention to detail, it is important that even when using BIM, tilt-up professionals closely inspect for compatibility with other structural members. This extra attention will provide dividends as the project advances.
BIM is being used for a tilt-up three-story office/retail building in Kansas City, Mo. The 66,900-square-foot facility has retail on the first floor and office space on the second and third. The project was converted from conventional metal stud/brick veneer façade to tilt-up. The selling points for the conversion included a faster construction schedule and reduced cost.
According to Karen Hand, P.E., project manager and project engineer at Needham and Associates Inc., BIM was a good choice to provide cost savings. “Our firm provided both the design and the detailing for the structure with our concurrent design and detailing process that uses our proprietary BIM software, BIG-DADi.
For this particular project, the amount of intricate and complicated panel detailing required made the tilt-up portion best suited to good old fashioned hands-on detailing,” she says. The project had innovative tilt-up details that were used to solve some unusual challenges on the project.
BIM provided great benefits to this project. “By using BIM not only for design but also to include the steel detailing, the shop drawing review process time was greatly reduced,” says Hand. “It allowed the steel detailing and tilt-up detailing to occur simultaneously and in a timely manner. By providing joist and deck lists for the vendor, considerable time was cut from the schedule.”
Since in some areas BIM is in its infancy, there are many lessons to be learned from each project that incorporates it. The success of a BIM depends on what you want to achieve from its use. For example, Hand notes that on this project the architect created a BIM using REVIT to display the architectural features of the building and produced very detailed architectural drawings and 3-D images for the client. However, all the data created an enormous file that served only his purposes. “Although this information is useful to the architect, our purpose was to produce fabrication shop drawings,” says Hand. “Another separate BIM was produced to carry the information to the next level.”
For a project incorporating BIM to be successful, it is important that everyone trains on the same software. Many of the BIMs created have large files sizes, making it difficult to share information among all the parties. Although there are limitations to the software, it is clear that BIM is helping projects get completed quicker and more accurately. Tilt-up professionals have begun using BIM to further speed up the tilt-up design process and it is clear that BIM is here to stay.
TCA was founded in 1986 to improve the quality and acceptance of site cast tilt-up construction, a construction method in which concrete wall panels are cast onsite and tilted into place. Tilt-up construction is one of the fastest-growing industries, combining the advantages of reasonable cost with low maintenance, durability, speed of construction, and minimal capital investment.