Built Outcomes are validated with 3D Laser Scanning and BIM
Helm BIM provides Building Information Modeling as a service where our team models and coordinates MEP systems that will be installed during construction. By combining all of the MEP designs and managing an organized coordination process with project stakeholders, Helm BIM produces a model with all of the MEP systems coordinated within the design model. From the completed and most up to date BIM Model details such as the location of pipes, electrical conduit, ductwork, and other components can be identified. Information on their sizes, materials, and connections are also clearly represented in the model. MEP systems also make way for slab penetration points of different sizes indicating where these systems run vertically.
While BIM helps project stakeholders arrive at well-coordinated documentation for construction, validating that everything is being built in the right location throughout construction is critical to ensure the coordination effort was a success. Errors or slight offsets in the field can translate into larger coordination issues later in construction if they are not accounted for and adjusted in the project’s centralized coordination model. Errors in the field can either be a misplaced MEP element or an in concrete slab sleeve that is incorrectly placed. As a BIM Manager, Helm ensures that their coordination models have the latest and most accurate information throughout the construction process.
Helm BIM is the MEP BIM Trade Manager for a project in Center City, Philadelphia. The construction effort for this project is at the point where concrete has been poured for the ground floor up to the second floor. Cast iron pipe has also been hung on the ground floor areas and the client wished to ensure that these pipes were both placed and pitched as shown in the coordination model. Part of Helm BIM’s deliverable for this project is to 3D Laser Scan every two weeks to capture slabs and MEP elements as they go up on site.
By conducting regular site visits every two weeks, Helm BIM can catch issues early on and address them before they become major problems. For example, during their first visit to the Center City Philadelphia project site, the Helm team scanned the ground floor to verify that the cast iron pipe was being placed correctly. Above are examples of the project BIM model being overlayed with the scan data captured on-site. The cast iron pipe in the basement was verified to have been installed as planned. Helm works with the client to understand the construction schedule so return visits can be scheduled when critical milestones must be scanned.
To the right is an RTC360 by Leica Geosystems. Our team picked a day when weather was clear and visited the construction site to complete the scan. In this picture the scanner is set up on the second floor where the Helm Team captured a section of sleeves to be evaluated against the coordinated BIM Model.
Below is a view of the sleeve locations in the concrete slab on Level 2. These sleeve drawings are produced from Helm’s BIM Coordination effort that took place in the 3D Model. The purpose of 3D Laser Scanning is to gather the conditions in the field and overlay them with the scan data. The picture following the sleeve drawing is the point cloud produced from Helm’s on-site scan. By overlaying the two sets of information our team was able to ensure that all the sleeves in this part of the 2nd floor were in the correct place.
Helm’s Team also applied the same process on the ground floor area where 12 inch cast iron sanitary pipe was beginning to be hung up. Below is a sample of the cast iron pipe in the shop drawing and the scan validated that the pipe in this corner of the building was being put up accuratley.
Below highlights an area where a discrepancy occurred in the field. The 15 inch sanitary pipes within the wall were both supposed to be housed in a room per the design model. However when the construction team assessed conditions in the field they noticed that the connection on one of the pipes resulted in the pipe potentially interfering with the left side of the room. To avoid this the team had to reduce the size of the room housing these two areas of piping
On Helm BIM’s weekly coordination call, the model and the point cloud were linked together and showcased to the team. Helm showed that the cast iron pipe that was hung in was done so in accordance with the way it was coordinated in the project’s BIM Model. Below are two screenshots from the fly through we provided for the stakeholders involved in the coordination effort.
As construction continues, Helm’s team will in turn continue this process of scanning and comparing to the BIM models to ensure systems and sleeves are placed in the correct places. While arriving at coordinated documentation through BIM is an accomplishment in itself, Helm ensures that success is realized in the field by pairing coordination efforts with 3D laser scanning technology.