In mining engineering, blast-induced ground vibration has become one of the major concerns when production blasts are conducted, especially when the mining areas and the blast sites are near inhabited areas or infrastructure of interest. To comply with regulations, a vibration monitoring program should be developed for each mining operation. The vibration level, which is usually indicated by the peak particle velocity (PPV) of the vibration waveform, should fall below the maximum allowable values. Ideally, when blasting is near structures of interest (power towers, dams, houses, etc.), the vibration level (PPV) should be predicted prior to the actual production blasts. There are different techniques to predict the PPV, one in particular is the signature hole technique. This technique is based on signals and systems theory and uses a mathematical operation called convolution to assess the waveform of the production blast. This technique uses both the vibration waveform of an isolated hole and the timing function given by the timing used in the blast. The signature hole technique requires an isolated single-hole waveform to create a prediction. Sometimes this information is difficult to acquire, as it requires the synthesis of a single-hole vibration waveform from a production blast vibration signal. The topic of ground vibrations from mining blasts, and more specifically the synthesis of a single-hole vibration waveform, has been studied by researchers in past decades, but without any concrete success. This lack of success may be partially due to the complexity and difficulty of modelling and calculation. However, this inverse methodology can be very meaningful if successfully applied in blasting engineering. It provides a convenient and economical way to obtain the single-hole vibration waveform and make the prediction of a production blast waveform easier. This dissertation research involves the theories of deconvolution, linear superposition, and Fourier phases to recover single-hole vibration waveforms from a production waveform. Preliminary studies of deconvolution included spectral division deconvolution and Wiener filtering deconvolution. In addition to the adaptation of such methodologies to the blast vibrations problems, the effectiveness of the two deconvolution methods by the influence of delay interval and number of holes is also discussed. Additionally, a new statistical waveform synthesis method based on the theories of linear superposition, properties of Fourier phase, and group delays was developed. The validation of the proposed methodology was also conducted through several field blasting tests. Instead of synthesizing one normalized single-hole vibration waveform by deconvolution, the proposed statistical waveform synthesis methodology generates a different single-hole vibration waveform for each blast hole. This method is more effective and adaptable when synthesizing single-hole vibration waveforms. Recommendations for future work is also provided to improve the methodology and to study other inverse problems of blast vibrations.

The first step in many mining operations is blasting, and the purpose of blasting is to fragment the rock mass in the most efficient way for that mine site and the material end use. Over time, new developments to any industry occur, and design and implementation of traditional techniques have to change as a consequence. Possibly the greatest improvement in blasting in recent years is that of electronic detonators. The improvements related to safety and increased fragmentation have been invaluable. There has been ongoing debate within the explosives industry regarding two possible theories for this. Shorter timing delays that allow interaction between adjacent shock waves or detonation waves, or the increase in accuracy associated with electronic detonators. Results exist on the improved accuracy of electronic detonators over that of electric or non-electric, but data on the relationship between the collision of dynamic stress waves and fragmentation is less understood. Publications stating that the area of greatest fragmentation will occur between points of detonation where shock waves collide exist, but experimental data to prove this fact is lacking. This dissertation looks extensively at the head on collision of shock (in the rock mass) and detonation (in the detonation column) waves with relation to fragmentation through a number of small scale tests in concrete. Timing is a vital tool for this collision to occur and is the variable utilized for the studies. Small scale tests in solid masonry blocks, 15 x 7⅞ x 7⅞ inches in size, investigated shock and detonation wave collisions with instantaneous detonation. Blocks were wrapped in geotextile fabric and a wire mesh to contain the fragments so that in situ tensile crack formations could be analyzed. Detonating cord was used as the explosive with no stemming to maintain the shock pressure but reduce the gas pressure phase of the fragmentation cycle. Model simulations of these blocks in ANSYS Autodyn looked at the stress and pressure wave patterns and corresponding damage contours for a direct comparison with the experimental investigation. Detonation wave collision in a single blast hole was found to positively influence the fragmentation and throw of the material. Mean fragment size decreased compared to tests with no detonation wave collision. Area of greatest throw occurred at the point of detonation collision where a buildup of gas pressure exited the block from one location. Head on collision of shock waves did not positively influence the muck pile. Largest fragments were located at the point of shock collision. The lack of particle velocity with relation to shock collision in previous literature could be attributed to the increased particle size here. Directional particle velocities could actually increase the strength and density of the rock at this location, decreasing the degree of fragmentation rather than increasing it.

El presente trabajo de investigación busca implementar una metodología de diseño de mallas de perforación y voladura en la empresa Minera Sotrami S.A, perteneciente al rubro de pequeña minería, con fines de estandarizarlo. La ejecución de dicha investigación se realiza mediante la utilización del algoritmo matemático de Holmberg que permite definir un modelo numérico para el diseño de una malla de perforación, y con la consideración de criterios operacionales encontrar una malla técnica que permita mejorar los rendimientos en las labores de exploración y desarrollo. Para el logro del mismo, se consideró como variable fija el tipo de roca (tipo III A) y las características geomecánicas presentes en ella; el diámetro del taladro de perforación como variable fija; y, el tipo de explosivo y accesorio de voladura como cambiantes, ya que se reemplazó la utilización de guías, mecha de seguridad y dinamita por el empleo de detonadores no eléctricos (Exaneles) y emulsiones encartuchadas. La oportuna y pertinente estandarización del proceso de perforación y voladura permitió obtener los siguientes resultados: el avance por disparo pasó a 1.62 m, el factor de carga se redujo a 13.46 kg/m y el factor de potencia disminuyo considerablemente. / This research work seeks to implement a design methodology for drilling and blasting meshes in the company Minera Sotrami S.A, belonging to the small mining sector, with finality to standardize it. This research is carried out by using the Holmberg mathematical algorithm that allows defining a numerical model for the design of a drilling mesh, and with the consideration of operational criteria, finding a technical mesh that allow improving the performance of exploration and development labors. To achieve it, the type of rock (type III - A) and the geomechanical characteristics present in it were considered as a fixed variable; the diameter of the drill as a fixed variable; the type blasting attachment and explosives as changeable, since the use of guides, safety wick and dynamite was replaced with the use of non electric detonators (Exaneles) and encapsulated emulsions. The opportune and pertinent standardization of the drilling and blasting process allowed obtaining the following results: the advance per shot was to 1.62 m, the load factor was reduced to 13.46 kg/m and the power factor decreased considerably. / Tesis