Manufacturers of drilling equipment and blasting contractors are increasingly looking to improve the drilling, blasting and excavation process through the automation and use of ‘intelligent’ solutions and in ways that combine the planning of the entire tunnelling process in a holistic manner. This is being achieved through the development of a number of IT and cloud based systems that are set to improve drill and blast productivity by marrying drill plans with the geology and layout of the site in real time.
This means, in practical terms, that tunnelling equipment and services are being created with in-built intelligence and automation. In effect, the systems enable tunnelling jumbos, as an example, to work seamlessly with the often complicated and involved drill+blast tunnelling process to deliver improved productivity, performance and occupational health and safety.
Other systems are being designed to undertake remote monitoring to ensure that blasting is targeted, measured scientifically and are more effective. In combination these systems offer contractors and tunnelling companies the ability to monitor how excavation is progressing, and vitally, to be able to make changes and corrections seamlessly and as the needs arise.
As a leading service supplier to the drill+blast excavation industry, the EPC Groupe of France has recently developed EPC Metrics, which is a set of software aimed at providing a dedicated remote monitoring service for blast vibration and air over-pressure measurement. Developed in partnership with Datum Monitoring Services, to the system facilitates the immediate access of event data, via state-of-the-art fixed monitoring stations and removes the need to travel to and from a monitoring location to undertake time consuming manual download of results in the field.
Ideal for both short and long term projects, these remote monitoring stations may be installed at both internal and external locations around a site, each with its own dashboard to customise and set trigger levels remotely. Once triggered, these stations automatically transmit data to a cloud-based server with results being immediately sent to a web portal providing users with instantaneous access to event information. Once the data has been received, the platform is capable of sending alerts, via customised texts and emails, to specified recipients. This is a major development in terms of onsite blasting safety.
“EPC has provided traditional blast monitoring services for a while, but EPC Metrics takes this offering to another level,” explained Dr Geoff Adderley, Commercial Manager for EPC Metrics. “A fixed monitoring location provides a consistent point of reference for reliable results, while the real-time transmission of data saves customers both time and resources. The EPC Metrics web portal also provides instant access to both current and historic events from a monitored location, providing a comprehensive life-cycle view of a particular site.”
The advanced monitoring stations incorporate a GSM (global system for mobile communications) modem for wireless data transmission, together with the option for solar power, enabling the service to be used in the most isolated of locations. “EPC Metrics offers users a more efficient way of monitoring blast vibration and air over-pressure, aiding the tracking of compliance and providing a greater understanding of site characteristics,” added Adderley.
Working alongside, or independently, of its Metrics system, is the EPC Premium application. Developed in partnership with RedBird (Airware), the system provides a collaborative approach to 3D mapping in order to optimise the value chain. Raw data is collected by high-resolution photography and processed within the EPC Premium application to present a fully interactive 3D mapping of a tunnel heading. Hosted and displayed on the RedBird Cloud platform, EPC Premium allows for the evaluation of underutilised site monitoring data.
The collected data, when complemented with data input from other sources, generally from the charging-transport level, the combined data provides operational blasting staff the information needed to improve blasting performance indicators, either across a series of blasts, during a period of observation, from face to face, or any other criterion to be monitored. The data obtained will provide additional information on the location of new blasts, as it is compatible with commercial software packages such as AutoCAD, Geomensura and Coralis.
The real benefit for tunnelling contractors is that the system provides more accurate data on which to base their blast designs. Up to now, the indicators describing how a blast performed were qualitative and visual; essentially according to the shape and spread of the muck pile. By using the new system blasters will have access to ‘hard’ data entered by EPC from its own Expertir software.
The EPC systems have been designed to assess all major parameters of the drilling process, including number of holes drilled, volume of the blasted muck pile, length of each pull, as well as hole-by-hole data the energy used, for example the physical parameters of the hole, its GPS coordinates, the name and quantity of the explosives used, the emulsion formula and the detonators applied. As soon as a blast has taken place, this data is sent to the cloud platform.
Through accessing the available data, blasting personnel can review performance indicators and rate the blasting process according to environmental criteria, taking into account vibrations, CO2 emissions, complaints from residents, dust emissions, etc.
Essentially it is through integrating data from the explosives charging machines and the results of each drill+blast round that users can quantify a ‘quality blasting’. This in turns enables them to measure the impact on other elements of the tunnel excavation process including transport times, charging times, explosives energy optimization, energy consumption, cycle times, rock crushing and so forth. Thus, the system aims not only to improve drill+blast rounds, but also the efficiency and cost effectiveness of the entire tunnel excavation process.
Manufacturers of tunnelling jumbos have not been slow to realise that equipment performance can be improved dramatically through the use of ‘intelligent’ technology. These developments provide benefits that transcend the traditional customer-supplier dynamic.
One such solution-focused operating platform is the Dynamic Tunnelling Package of automation software for face drilling rigs developed by Atlas Copco. This provides improved accuracy by ensuring that drill plans always match the heading in which the jumbo is working. By using this software, the drill rig can create its own drill plans directly at the face by downloading the contours of the tunnel to the drill rig together with a drill rule file.
The real value of the software is that today all tunnelling models exist as a 3D model. Traditionally drill plans were prepared manually and were imported into the drilling jumbo. The Atlas Copco Underground Manager development, which was field tested recently in Norway, enables the importing of the 3D tunnel model along with a set of drilling rules via a USB or Wi-Fi connection. The drill rig then generates its own precise drill plans based on its exact location at the face and for the cross section to be excavated.
“Today, in tunnelling projects, especially those in urban areas, there are differences in the cross section. In the past, the blast engineer went up and down to the face with the drill plans”, said Johan Jonsson of Atlas Copco. “With our Dynamic Tunnelling Package, the drill plan is generated on the drill rig and at the tunnel face.”
The new Dynamic Tunneling Package of software comes in addition to Atlas Copco’s long time options including the ABC Regular, which consists of digital drill patterns to control over and under brake and achieve a more accurate profile and the ABC total package which consist of fully automatic drilling and positioning of booms which helps to achieve better precision, more accurate hole alignment and faster advance rates over the drill cycle.
In recent months Sandvik Mining and Rock Technology has introduced new drilling jumbos with new features and equipped with some of the latest tunnelling software on the market.
The new Sandvik DT912D, DT922i and DD422iE jumbos are purpose designed to accommodate various levels of automated drilling from the simplest of facilities to the most sophisticated and highly integrated of packages.
The entry-level silver package provides for assistance with drilling angles and monitoring of hole depth. The standard gold package facilitates drilling according to predefined drill plans and includes features such as drilling to predefined depth, drill plan visualization, rig navigation and an option for automatic long-hole drilling. The enhanced platinum package includes all features of the gold package and adds the setting of automatic boom movements and drilling cycles for full automatic face drilling. This is enabled via integration of the Sandvik iDATA system.
The gold and platinum packages are integrated also with the Sandvik iSURE® tunnel management tool for accurate drilling, charging and blasting plans. In addition, iSURE® provides useful data collection and analysis for improving the work cycle with the process being complemented with the addition of a rig-integrated on-board rock mass analysis and visualization system, known as geoSURE.
Designed to be used with Sandvik underground drill rigs, this system delivers real time on board analysis of the rock mass and provides important information for the assessment of rock reinforcement or injection requirements. It serves additionally as a tool for assessing charge and blast control as well as a complementary tool for geological mapping.
What is really revolutionary, is that the rig-integrated system enables the jumbo drill rig to act as a geological analyser as all information is provided in real time and on the drill rig itself. This eliminates the need for any third party devices, add on sensors or separate data transfers. The rig makes full use of the drilling information to provide accurate and repeatable results. Its real time on-board analysis covers such elements as fracturing, rock strength and water detection, with the extended analysis of the data enabling the evaluation of the rock strength class, rock quality class and rock quality number.
The above features may then be further visualized using the iSURE® software, with its 2D planar view providing an overall outlook of the tunnel section, including 2D interpolation, side view, top view and unrolled view. For more detailed inspection, the 3D structural view of the tunnel section may be used. This feature, which is being refined and further developed, uses 3D interpolations, plane intersections and isosurfaces and curves. When used in conjunction with iSURE®, it also provides the former 3D view and one hole MWD diagram working with the new rig-integrated rock mass analysis and visualization system variables.
The iSCAN 3D scanning and navigation system has been developed for process optimisation, with two on-board scanners, integrated with iSURE, providing accurate navigation data. This eliminates the need for the separate surveying phase of the process. The automatic scanning process is available as an option on the new DD422iE tunnelling jumbo, which uses lasers to guide the drill to its exact position, saving valuable setup time on each drilling cycle. It also measures angles and distances around the rig, comparing them with previous scans in its memory to locate a drilling setup with high precision.
Performing a continuous over-break and under-break analysis, the scanning unit also helps optimize the drilling and blasting cycle and produces an accurate profile. This ensures that the tunnel is excavated as close to the planned layout and size as possible, with 3D scanning analysing blasts and continuously relaying information. Using smart iteration cycles, iSCAN effectively analyses the geomechanical plane of the rock to increase accuracy, reduce cycle times and ultimately enable more drilling at less cost.
The developments mentioned highlight how drill+blast operations are becoming more scientific, being able to benefit from hard-data and automated drill plans based on real time information. By integrating drill+blast cycle data with the entire tunnelling operation, contractors will be better able to plan their operations, and coordinate all their activities. The next step, undoubtedly, will be the ability for equipment and services from different manufacturers to be shared, thereby presenting even greater levels of flexibility in tunnelling operations.