A Complete Picture from Land and Sea
Introduction
Arctic Mineral Resources AS required a comprehensive and detailed terrain survey for their AIM 4-0 project in Vevring, Sunnfjord municipality, western Norway. The survey served two purposes: as a baseline for environmental monitoring and as input for detailed mine design.
Danish LE34, the largest provider of surveying and land management services in Scandinavia, was contracted to conduct a 3D scan of the planned mine entrance and an existing road tunnel that intersects the project area. LE34 also mapped the shoreline and seabed of an adjacent fjord to gather necessary site information.
Although inclement weather initially caused a 10-month delay in the surveying project, various Trimble surveying tools were used to quickly collect the required data over two workdays during a picturesque weekend in August 2022.
Overview
Arctic Mineral Resources AS ("AMR") is a sustainable mineral resources developer and the sole owner of the AIM 4-0 (aim for zero) project. This project involves mining armor stone and industrial minerals with a commitment to showcasing sustainable mining practices by achieving zero tailings deposits, zero waste rock, zero permanent footprint and zero conflicts with the local community. The project is located on the western side of the 300-meter-tall Engebø mountain near the Vevring township, adjacent to the stunning Førdefjord.
A more detailed analysis of the mine's environmental impact and technical design considerations was necessary to transition the project from a pre-feasibility study to a bankable feasibility study.
AMR contracted LE34 to conduct a 3D terrain survey of the project area and its surroundings. This involved scanning the proposed aboveground mine entrance and a 630-meter-long regional road tunnel that intersects the resource. Additionally, LE34 mapped the steep shoreline of the Førdefjord to determine the optimal location for a seaside quay and mine entrance. They also completed a bathymetry survey of the 300-meter-deep fjord and mapped its submerged edge for mine planning purposes.
Furthermore, LE34 assisted AMR in installing local control points for future surveying activities and recorded the locations of diamond drill holes used to sample, classify, and model the deposit concealed beneath the surface and within the Engebø mountain.
Ethan Barnes, AMR Geologist, said, "All operating mines and mines under construction have detailed terrain surveys for environmental monitoring and mine development. We intended to complete this detailed work ahead of schedule and capture a snapshot of the natural landscape and existing infrastructure before AMR starts civil work. This detailed mapping assists us in mine construction planning and holds AMR accountable to our stakeholders—residents, environmentalists, and government bodies. We can now always check to see how things were before any intervention occurred."
Trimble MX9 mobile mapping system mounted on a local boat for scanning the shoreline of the Førdefjord.
Most of the mine and critical infrastructure will be underground to minimize surface impact and reduce environmental harm. The surface area will be limited to the mine entrance, a quay, and vertical shafts for mine ventilation and emergency exits.
Rock excavation will occur in large interconnected underground halls and tunnels, with pillars providing support. The mine design encompasses the Engebø mountain from its peak to 330 meters below sea level, with an expected mine life of more than 50 years. LE34's accurate topography model, above and below water, allows AMR to develop a robust and safe long-term mine plan for constructing and operating the AIM 4-0 project.
The underground AIM 4-0 mine model is displayed in LE34’s web-based point cloud tool PointView®
Solution
With 26 offices across the Nordic region and access to a comprehensive range of Trimble solutions and technical expertise, LE34 presented AMR with a holistic mapping solution for the project area.
To tackle this multifaceted task, LE34 utilized various Trimble tools, including the Trimble® MX9 mobile mapping system, the Trimble X7 3D scanning system, the Trimble S7 total station, the Trimble R12i GNSS receiver, the Trimble Alloy GNSS receiver, and the local Trimble VRS Network.
Anders Nygaard Møller, Director of LE34, expressed the importance of Trimble's reliable customer support, saying, “LE34 operates in numerous countries worldwide, such as Singapore, Spain and Scandinavia, so having dependable customer support from Trimble is crucial to us. When we're in the field, we can count on getting phone support for mobile mapping within 30 minutes to troubleshoot and resolve any issues."
LE34 established control points in the Vevring tunnel with a Trimble S7 total station, followed by mobile mapping with a Trimble MX9.
Before scanning the tunnel with the MX9, LE34 combined the capabilities of the S7 and the R12i alongside Trimble Business Center (TBC) software. This approach enabled the establishment of control points, thus ensuring a highly accurate point cloud. The installation of control points across the 630-meter tunnel took less than two hours for the LE34 team to accomplish. Additional control points were set up outside the tunnel. These served to survey drill holes and compute the location, azimuth, and inclination—all of which are crucial inputs to AMR’s geological model.
A side-by-side display of the point cloud data within LE34’s PointView software and the Trimble MX9 affixed to a vehicle scanning the existing tunnel.
The MX9, mounted on a vehicle, gathered data along the road within the Vevring tunnel, ensuring no disruption to traffic. This method proved faster and safer for the survey crew than traditional ground surveying. For the Førdefjord shoreline survey, the MX9 was affixed to a boat, enabling valuable data collection from areas inaccessible from land or sky.
The MX9's high point cloud density ensured complete data capture, eliminating the risk of data gaps. Given that Vevring is a 15-hour drive from LE34's primary office in Copenhagen, revisiting the site would neither be cost- nor time-efficient.
Usually, LE34 transfers all data to the office via the Trimble cloud service. However, the remote location necessitated local backups to PCs, with data transferred to the office later. The team leveraged TBC's field-to-finish survey CAD software for data processing, ensuring efficient management of mobile mapping point clouds and producing a range of deliverables.
Møller praised the approach: “Mobile mapping reduced the time we spent on the road and in the tunnel, which enhanced safety for our field crew. The office workers also gained valuable insights and knowledge from the vast amount of quickly collected data. Trimble's TBC software streamlines the processing of mobile mapping data—from raw data to usable point clouds in just a few hours."
Møller praised the approach: “Trimble's TBC software streamlines the processing of mobile mapping data—from raw data to usable point clouds in just a few hours."
LE34 mapped the future tunnel entrance with a Trimble X7 3D scanner.
In the area outside the Vevring tunnel, the X7 scanner was deployed to estimate the volume of excavated rock piles and to capture a small area intended for the mine site entrance. The Trimble Perspective software, connected to the X7, registered data in the field and validated measurements, reducing office processing time. The scanning process with the X7 was completed within two to three hours.
Screen shot from PointView showing Trimble X7 scan data overlaid with tunnel model.
The R12i GNSS receiver was employed to determine absolute coordinates for the primary control points to create an accurate local control point grid. Concurrently, the S7 total station assessed the internal geometry of the reference points. During the boat survey, an Alloy GNSS receiver and Trimble VRS Network provided access to RTK corrections, enhancing the data accuracy of near-shore seabed scans. In total, the data collection for both the surface and tunnel was completed within 2.5 field days.
LE34 mapped the fjord’s shoreline, seabed, and harbors using the Trimble MX9 and the Norbit Multibeam Sonar.
Successful Outcome
Back in the office, the LE34 team transformed the collected data into deliverables for their client. These included point clouds, a surface model, and a control point grid. They also offered coordinates for drill holes and the necessary detail to compute the azimuth and inclination.
Even though an integrated 3D model was not explicitly required, the team gathered all point cloud data, making it readily available upon request. This method of capturing most of the data in two campaigns resulted in significant time and cost savings for the client.
The high-quality point cloud data set for the road tunnel, accompanied by control points, provides a valuable reference, enabling AMR and its stakeholders to revisit the tunnel throughout mine development and operations to monitor any changes. By leveraging Trimble's laser scanning and mobile mapping equipment with integrated software, LE34 experienced cost and time benefits. Access to multiple tools allowed the team to select the most suitable approach for each project phase.
“LE34 is a long-time Trimble customer, having first purchased Trimble RTK receivers in 1995,” said Møller. “Trimble products are reliable, accurate and high quality. We continue to expand our service offerings by updating our technology with different kinds of Trimble hardware and software.”
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