How Complexity Analysis contributes to blasting practice

摘要

Blasting in geological bodies is an industrial process acting in anenvironment characterized by high uncertainties (natural joints, faults, voids, abruptstructural changes), which are transposed into the process parameters (e.g. energetictransfer to rock mass, hole deviations, misfires, vibrations, fly-rock...). The approach tothis problem searching for the “optimum” result can be ineffective. The geologicalenvironment is marked out by too many uncertainties, to have an “optimum” suitable todifferent applications. Researching for “Robustness” in a blast design gives rise to muchmore efficiency. Robustness is the capability of the system to behave constantly undervarying conditions, without leading to unexpected results. Since the geology varies fromsite to site, and often from bench to bench on each site, setting a robust method cangrant better results in varying environments, lowering the costs and increasing benefitsand safety.Complexity Analysis (C.A.) is an innovative approach to Systems. Under this point ofview, the blast is a System consisting of drilling, charging and initiation parameters asan input, the geology as the working environment and the fragmentation as the output.C.A. allows to analyze the Complexity of the Blast System and the criticality of eachvariable. The lower is the complexity, the more robust is the System, and the lower isthe possibility of unexpected results; critical complexity is the point beyond which thesystem starts to become unstable, being able to change behavior unexpectedly and causesurprises.By performing C.A. on field data and on the models used to design blasts, we candeduce: the complexity degree of each model; the complexity degree of a real blast;how much each variable influences the resu which variable is more critical.By knowing the complexity of the blast, the method which grants the highestperformances can be chosen. By identifying the criticality of variables, the part of thework to be focused in order to solve the problems encountered is also known.The paper presents the results obtained thanks to the C.A. approach in an undergroundgypsum quarry (Northern Italy), exploited by conventional Rooms and Pillars methodby drilling & blasting.