- The University of Victoria is building a new Student Housing and Dining facility to provide accommodations for over 600 students currently living off campus.
- In addition to providing field survey support for survey layouts and point cloud as-builts, GeoVerra provided floor flatness and floor levelness (FF/FL) assessments of all concrete floors and slabs.
- By providing construction survey layouts, FF/FL assessments, and final point cloud as-builts, GeoVerra saved the client costs by effectively combining field visits, data processing, and deliverable production tasks.
The University of Victoria Student Housing and Dining Project is the first significant capital project from the 2016 Campus Plan. It will provide 621 additional beds to accommodate students currently living off-campus, including traditional dorm rooms and new “community-living” style rooms made up of single rooms with a shared kitchen and living area.
A secondary contractor engaged GeoVerra to provide field survey support, layouts, and as-built surveys. In addition, the contractor asked GeoVerra if they could assess flatness and levelness of the concrete floors for the 8 and 11-storey structures (19 floors). The timeline for the survey work and floor assessments was approximately 18 months and construction of both buildings will continue until early 2023.
I often think of geomatics as the center point between the design world and the real world. GeoVerra is the intermediary between the computer and the physical world to facilitate and minimize the number of steps between the two. By using GeoVerra as the construction surveyor and the laser scanning team, we can integrate and relate the scanning results with the survey data, in addition to time and cost efficiencies for survey crews, data processing, and stakeholders.– Hugo Chisholm, Project Manager, GeoVerra
The construction survey phase of the project included providing reference gridlines for construction crews to use as markers for important structures, such as walls and elevator shafts. Conventional surveying methods were used for the construction layout services and included setting site benchmarks and providing final survey layout and as-built sketches.
For the floor flatness (FF) and floor levelness (FL) assessments, the American Society for Testing and Materials (ASTM) standard defines that testing can be done using a 3D laser scanner. GeoVerra’s geospatial group had used this piece of equipment for surveying other project types, such as creating 3D models of buildings, but was new to the software required for floor assessments. The team was eager to support the client and quickly got up to speed on the ASTM testing methodology and 3D data processing software.
Using the same crews who were already on-site for grideline work to do the floor assessment meant time and cost savings, consistency in deliverables and having a team that was familiar with the project. Another advantage was providing the architects with a full picture of the project by overlaying the 3D laser scanning point cloud results with the CAD survey model in the same coordinate space.
Having a broad range of tools available and a team with expertise in a wide variety of fields, including civil and structural engineering, enables GeoVerra to be flexible, resourceful, and responsive to client requests providing operational and cost efficiencies.
The team is now looking into new, cutting-edge methods that will enable FF/FL results to be provided on-site in real-time, allowing for concrete slabs and floors to be remediated while the concrete is still soft. This will provide significant time and cost savings for contractors when compared with traditional remediation methods of cured concrete, such as grinding or pouring self-leveling concrete.
Construction Layout Services
- Review IFC drawings and calculate critical layout locations
- Establish on-site survey control
- Survey layout of principle reference lines, main elevations/benchmarks, and intersecting gridlines
- Survey of formwork, slabs and cast-in items
- Provide survey as-builts and maintain current documentation and drawings
- Provide laser scan as-built data of completed structure, following the details of the expected deliverables, including point densities
Floor Flatness and Levelness
- The architect provided specifications for the overall and local FF and FL tolerances based on ASTM standards for trowel-finished floor surfaces.
- Using 3D laser scanning equipment and software, GeoVerra provided heat maps of the concrete FF and FL with 5 mm elevation ranges indicating peaks (blue) and valleys (red).
- The remote-operated 3D laser scanner rotates 360 degrees horizontally while collecting ~1 million distance observations every second.
- Several scans were completed using scan targets to combine the data into a single point cloud.
- The geospatial team used Leica Cyclone and TopoDOT point cloud processing software to create sample lines within the point cloud in order to test their FF/FL values against the minimum value provided by the architect.
- A heat map was then created with AutoCAD Civil3D for any areas that failed to meet the minimum value to help identify problem areas on the floor surface.
- The heat maps enabled localized mitigation of the concrete, which was then rechecked with a conventional straight edge.
- Survey layout and as-built data in CAD format and PDF sketches.
- Floor assessment report including as-built FF and FL values with a 90% confidence interval and associated pass/fail based on ASTM standards.
Ready to Start?
As one of Canada’s largest geomatics companies, we have field offices dotted from British Columbia to Ontario so that we can deploy teams with local knowledge at the drop of a hat and scale quickly to meet project needs.