At the beginning of major mining or civil engineering projects, one of the more manual, technically challenging and hazardous tasks involves rock and land surveying.
The process of inspecting rock faces, for example, is a manual one through which geologists measure the failure planes and joints on the rock face in the field. In environments like mine pits, quarries and large construction sites, this has safety implications as people share spaces with large vehicles and plants.
Surveying can also be disruptive and requires formwork such as scaffolding, which is costly and time consuming. With road construction and tunnelling projects, for example, lanes are generally closed and scaffolding is erected or elevated work platforms used so that geologists can reach the cliffs that they need to measure.
Manual mapping processes also face challenges in terms of consistency, sample sizes and quality issues associated with the repetitive nature of data collection tasks.
Thanks to technological advancements, however, land and rock surveying are being transformed by digital mapping. Under this concept, technologies such as drones and UAVs are sent into remote or difficult to access environments to capture data often over a large area.
A handful of vendors now offer digital land and rock surveying solutions. Engineering companies themselves, as well, are getting in on the action. In May, multi-national engineering and infrastructure advisory outfit Aurecon announced it was prototyping software which uses drones to capture digital images of rocks and sites in order to create 3D models. The company said it has developed algorithms to extract the data from the photos so that it can automatically identify the areas that need to be measured.
According to Dr. Eduard Vorster, Aurecon client director, resources, Africa said digital mapping can help to solve problems in several areas.
First, there is the issue of inconsistencies in data collection. Under current manual processes, Vorster said the result from the mapping of rock and soil faces varies according to the individual who has undertaken this task and thus the quality of output depends upon the skill of the individual involved. Moreover, whilst this is a technically challenging task which requires years of experience, the actual logging process is in fact often performed by a relatively junior person.
By eliminating much of the human element associated with data capture, however, Vorster says digital mapping will provide greater consistency across a range of areas. These include identifying minerals to inform valuable mining plans, excavation plans or foundation planning.
Next, there is the quality and quantity of data.
Under current mapping processes, the quality of logging and mapping can be impacted by boredom and repetition. As well, the mapping of large surfaces in open pits, long road cuts or large infrastructure foundation areas is often given to less experienced workers as part of their development. Even where experienced personnel are used – as is often the case, for example, for large dam foundations – the magnitude and repetitive nature of the task involved means this is highly subject to errors.
Under manual processes, the size of the sample taken during ground investigations is also often comparatively small relative to the scale of the overall development.
Digital mapping, Vorster says, addresses these issues. First, by automating much of the bulk data capture, it refocuses expert opinion away from this and toward validation and checking. As for the quantity issue, GIS positioning and utilisation of data in spatial models would enables much wider data capture and data mining.
Finally, there are issues such as time and safety. Particularly in spatially extensive environments, such as open pits, long tunnels or road cuttings and quarries, the process of geo-positioning and data is time intensive. As mentioned, manual data capture processes can also see when workers are placed in potentially hazardous situations.
Digital mapping, Vorster says, shortens the time frame required for data capture and avoids much of the need for people to enter hazardous environments.
Moreover, when done well, Vorster says digital mapping offers new opportunities and abilities. Primarily, he says, these revolve around greater consistency of data capture, effective and specially designed data storage and the opportunity to refocus human expertise on interpreting data rather than necessarily capturing the data itself.
“Examples of the types of things we can do with digital mapping which could not be done with a more manualised form of land surveying include providing a holistic view of a site in much less time and effort,” Vorster said in a written response to questions from Sourceable.
“Manual logging requires the input of data of very specific target areas, which means you have a much smaller sample of the area that is being logged. The data captured in such a way is often paper-intensive or at best half-digitised only (e.g. captured on a tablet on an electronic form).
“Digital mapping and photogrammetry enables a holistic view, can be programmed for specific identification abilities, which isn’t simply an uncoupled mapping of features, geology and terrain, but a complete dataset that is created through the coding of identifying features that can be mined for value. The data of the various features that are considered important can then be analysed, such as fracturing, changes in geology, or changes in construction method impacting on a slope or tunnel areas, for example.
“Currently, many owners of historic data (for instance geotechnical data) find it very difficult to access such data for future use. Digital mapping provides the means to capture data measured in this way, to be accessible in a predetermined format for possible future use.”
According to Vorster, these abilities help project owners to save time and reduce project risk. The pace at which data can be logged and then handled to make decisions regarding excavation volumes or areas with stability constraints, for example, helps to lower both the cost and risk of project. By avoiding the need to rely on data from practitioners, digital mapping provides significant benefits in terms of data consistency. As mentioned, this enables expertise to be refocused around checking the validity of the data.
As they can compare readings on a 1:1 bases, project owners are able to gain a more accurate and complete idea of progress and changes on site.
For all these reasons, Vorster says digital mapping will facilitate greater reliability, better safety outcomes and opportunities to optimise the methodologies used for excavation, boring, or founding of infrastructure.
When implementing digital mapping in operations, Vorster says it is important to think about how the systems and platforms will manage increasing amounts of data which will be stored and analysed. This is important as the switch to digital mapping will see the volume of data captured grow exponentially.
Second, a holistic approach should be adopted. One trap to avoid, Vorster says, is a piecemeal strategy whereby specific projects are selected for digital mapping adoption on a selective basis. Where this happens, he says, the ability to derive efficiencies through digital mapping may be compromised. The organisation’s talent and base of expertise from a personnel perspective in regard to tasks such as data analysis, for example, may have to be revisited for each project.
it is important to avoid placing undue emphasis onto a specific type of technology such as drones without thinking through the complete package of the solution being provided.
Throughout Australia, digital technologies are transforming land and rock mapping practices.
With sensible strategies, companies can capitalise on these to deliver greater safety, efficiency and value to their projects.