Though the first blasting simulation concepts and software emerged 15 years ago, there is still a lot of misunderstanding around this amazing technology.
Basically, and as already mentioned in a previous article: "numerical simulation allows running multiple blast scenarios before selecting knowingly the most effective combination that best suits your operational objectives".
Starting from that point, a major point need to be clarified: a blasting simulation software is not a magic wand. This statement has several consequences:1. Should you want to obtain output from the software, you will need to feed it with inputs.
The axiom "garbage in, garbage out" supplements this one truth in a humorous way: precise and quality inputs are necessary to get fair simulation results. The simulation accuracy is then directly linked to:
- 1.1. A thorough knowledge of the explosives and initiators’ technical features
- The density and velocity of detonation of every single type of explosives in use
- The length, diameter, weight and packaging of every packaged explosives
- The water tolerance of the products
- The availability of the products
- The compliance of the ordered quantity with the site’s authorization (especially in Europe)
- The pre-set timing range of available products (for electric and non electric initiation)
- The timing scattering for every pre-set timing option or for every increment (electronic detonators) in percentage or absolute value
- The wire or tube length options available
- The compatibility of the initiation devices with your certification, training and environmental/meteorological conditions. Lightning, electrostatic or electromagnetic environments or very cold temperatures might impair the use of some type of initiators
- The blasting machine or initiation device you have on site. Shock tubes cannot be triggered with the same device as an electric detonator and every single brand of electronic detonators can only be triggered by their specific equipment
- 1.2. A consistent (good) quality of the field measurements.
As far as explosives are concerned, you will have to check the data and safety sheets of the products in use on your site. Do not hesitate to ask your supplier for additional details. Particularly critical to get are:
A smart choice of measurement equipments and devices will bring a decisive contribution to the accuracy of your predictions.
The measurements quality is vital and requires a specific training for the field operators in charge. The whole process has to be organized along a check lists format so the field measurements can be consistent from one shot to another. Part of the process aims to check the correct implementation of the theoretical and/or prescribed geometry.
The basic equipment kit to feed your model with adequate data has to include at least:
- Three seismographs equipped with Geophone & Microphone
- A burden probe
- A face profiling device (or a camera for stereoscopy 3D applications)
- A GPS navigation device
- A good quality digital camera
Asking your favourite blasting simulation software supplier might help you in choosing the right tool or the right brand. Partnerships between measurement or monitoring devices supplier and software developer results sometimes in easier, faster or smoother data upload or download.2. Blasting simulation is a simulation
Though the most advanced simulation software can achieve 90% accuracy in predicting blasting results, it is important to understand that a simulation is always based on past events and configurations. Most of the modern software gets a calibration functionality aiming precisely to enter measured post-blast outputs of a simulated operation, so the model can "learn by experience".
Unfortunately, the past is past and today’s blast geology and configuration thorough knowledge (as far as a thorough knowledge of a shot can be achieved) do not grant you omniscience for the next blast.
Blasting simulation software is now amazingly powerful and most of them take into account a large quantity of blast parameters. These systems remain decision-aid tools and do not replace blasters’ experience, field knowledge and a sense of safety.