Quarry management

The Maptek I-Site™ 8800 laser scanner allowed a large quarry in Leicester, UK, to devise practical, cost-effective safety strategies.

Oakes Surveys approached Maptek for help in conducting safety studies at the quarry, where weathering of the higher benches over decades of operation had resulted in loose rocks falling from the quarry faces to the floor.

Quarry management needed to identify the exact location of the sources of the rock falls. They also wanted detailed information on the number of falls in a given time, and the size of the rocks.

Surveying the quarry, which measured approximately 1000m by 600m by 150m, required a scanner capable of delivering high point density at long range.

The Maptek I-Site™ 8800 laser scanner collected data at the appropriate point density to detect small changes in a rock face at a distance of more than 0.5km.

High definition scan data was recorded from several scanner setups to collect point data for the entire quarry. The team set up the scanner at the same locations on subsequent visits.

Hundreds of millions of x,y,z data points were collected during each session, all accurately located within the site coordinate system.

Long range laser scanning is a safe, cost-effective and accurate solution which meets the challenges of monitoring and measuring rock falls from quarry faces.

Tight survey control, and the fact that the I-Site 8800 scan data had minimal noise, ensured an error free digital representation of the quarry faces.

The point cloud data was then processed in Maptek I-Site Studio™ software and accurate triangulated surfaces were created.

Surface data was divided into panels for comparing surfaces between quarterly site surveys.

Areas of change down to approximately 150mm were reported, along with the location and size of the fallen material.

Data from consecutive visits was easily compared to understand how the faces were developing and changing over time.
Detailed cross-sections of the quarry faces could be generated for rock fall analysis in simulation software.

Identifying the danger zones means that safety and ‘stand off’ berms can be appropriately placed to protect personnel from falling rock.

Reducing the need to install expensive netting unnecessarily on low-risk areas of the quarry makes for a more cost-effective solution.

Thanks to Oakes Survey
Full article published in Quarry Management