Construction Verification
- As-Built Surveys
- Construction Verification Reports
Sector: Construction & Engineering
About This Project
SurveyWorx were commissioned to manage & deliver the Survey & Engineering Specification, working in collaboration with the Construction & Design Teams who would lead the Construction/Development of the Project.
Deliverables/Outputs would highlight deviations between the As-Built Constructed Position & Design.
As-Built Drawings would be delivered to tight a programme/timeline to comply with our Contract on the Project. Accurate Survey Data/Drawings would provide Project Managers & Design Teams with vital information in relation to the true positional accuracy of constructed elements when compared against the Design Drawings.
The Charter Place Square Project is a mixed-use development in London, comprising over 500 Apartments/Homes with commercial space at Ground Floor level. The development comprised 6 RC Frame High-Rise Buildings/Structures, ranging from 12 to 26 Levels, incorporating a Sky Garden & Residential Terrace on the 26th floor, with associated shared amenity spaces & landscaping, car & cycle parking, ancillary spaces & refuse storage incorporated within the Scheme.
As-Built Survey Specifications
- Establish/Verify Control Network
- Slab Level Verification (+/- SSL)
- Slab Edge Position
- Columns – Position & Verticality
- Slab Openings/Penetrations
- Structural Beams Position & Level
Survey Methodology & Project Delivery
Using a combination of the latest integrated Robotic Total Stations, GNSS, HD Laser Scanning Technology & “Robust Survey Methods” to capture & verify accurate Survey Data, the Survey Specification was delivered both efficiently & cost effectively within the allocated timescales.
As-Built Survey Data was captured/acquired using Total Stations (1“) & Leica P40 HD Laser Scanners.
Establish Control Network
Primary Control Network & Grid System was Verified/Checked using a combination of Total Station (1“), Zenith/Vertical Laser Plummet, Steel Tape & Leica Precise Digital Level (DNA03).
Total Station Data Post-Processing
Raw Survey Data/Observations were Post-Processed through SCC Survey Software. Data was captured & coded using a specific Project Code List written within SCC. This ensured all features were assigned a specific Code when Surveyed & imported to a defined Layering System within SCC & exported to AutoCAD.
HD Scan Data Post-Processing
HD Scan Data was Post-Processed to produce a fully Registered/Coordinated Point Cloud, using Leica Cyclone Software. Point Cloud Data was referenced to the Site Control Network using Secondary Control transferred vertically through the Buildings/Structures using a Zenith/Vertical Laser Plummet. Post-Processing/Registration was completed using a combination of Target-Based Registration & Cloud-to-Cloud Registration.
Quality Assurance procedures were completed with a Point Cloud Registration Report exported to highlight registration accuracy. Registration was a success with an average error of +/-2mm between individual Point Clouds.
The Point Cloud was Verified/Checked by taking sample Cross Sections/Slices through the Data in order to check for any discrepancies between individual Point Cloud alignments. Point Cloud Data from the Internals was also Verified/Checked against the External Data to confirm successful Registration.
Coordinate Reference System
Survey Data related to the OS Network OSGB36(15).
Delivery & Output
Structural Design Drawings were Scaled/Transformed to Site Grid System using Grid Intersection Coordinates as references. Survey Data was imported & Drawings were completed to highlight deviations (+/- SSL) between As-Built Survey Data ‘True Position’ (+/-) & Structural Design Data.
Drawings were delivered in defined categories to aid Design Teams by providing accurate & concise information while avoiding cluttered/crowded Drawings. 1) Vertical Elements; Columns, Walls & Cores. 2) Structural Slab Levels; Floor/Slab Flatness. 3) Structural Openings & Formed Edges; Slab Edge; Openings/Penetrations & Balcony Bracket Halfen Channels.
The final Drawing Package included; As-Built Survey Drawings (approximately 375 drawings issued) & Control Network Reports. All Drawings were passed through Quality Assurance prior to final delivery.
The completed Surveys were delivered as a digital version in 2D AutoCAD & PDF formats.
Glossary
GNSS = Global Navigation Satellite Systems.
RTK = Real Time Kinematic.
GPS = Global Positioning System.
OSGB36 = Ordnance Survey National Grid Reference System.
ETRS89 = European Terrestrial Reference System.
WGS84 = World Geodetic System (GPS/GNSS).
Sample Delivery/Output
Services
