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Understanding the behavior of geomaterials under explosive loading is essential for several applications in the mining and oil industry. To date, the design of these applications is based almost solely on empirical equations and tabulated data. Optimal designs require accurate and complete knowledge of rock behavior under various loading conditions. The vast majority of the properties available in the literature have been gathered by deforming the specimen slowly. These properties have been used to establish constitutive models which describe the behavior of rocks under static and quasi-static loading conditions. However, the dynamic properties and material constitutive models describing the behavior of geomaterials under high strain-rate loading conditions are essential for a better understanding and enhanced designs of dynamic applications. Some attempts have been made to measure dynamic properties of rocks. Also, some trials have been made to devise material models which describe the behavior of rocks and the evolution of damage in the rock under dynamic loading. Published models were successful in predicting tensile damage and spalling in rocks. However, there are no established models capable of predicting compressional damage in rocks due to dynamic loading. A recently-developed model, the RHT model, was formulated to describe the behavior of concrete over the static and dynamic ranges. The model was also formulated to predict compressional damage based on the strain rate at which the material is subjected to. The RHT model has been used successfully in several applications. The purpose of this research was to characterize one rock type as an example of a hard brittle rock. The physical properties of the rock as well as the static and dynamic mechanical properties were investigated. These properties were used to calibrate the RHT model and investigate its potentials to predict compressional damage in brittle materials. The calibrated model showed good precision reproducing the amplitude of the strain signals generated by explosive loading. It was also capable of predicting compressional damage with acceptable accuracy. Unfortunately, due to implementation restrictions, tensile and spall damage could not be captured by the model. The duration and shape of the strain pulse were also poorly modeled. / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2010-12-22 17:54:05.887

Blasting is a critical part of most mining operations. The primary function of blasting is to fragment and move rock. For decades, attempts have been made at increasing the efficiency of blasting to reduce costs and increase production. Most of these attempts involve trial and error techniques that focus on changing a single output. These techniques are costly and time consuming and it has been shown that as one output is optimized other outputs move away from their optimum level. To truly optimize a blasting program, the transfer of explosive energy into individual components must be quantified. Explosive energy is broken down into five primary components: rock fragmentation, heave, ground vibration, air blast, and heat. Fragmentation and heave are considered beneficial components while the remaining are considered waste. Past energy partitioning research has been able to account for less than 30% of a blast’s total explosive energy. The purpose of this dissertation was to account for a greater percentage of the explosive energy available during a blast. These values were determined using measurement techniques not previously applied to energy partitioning research. Four small-scale test series were completed, each designed to isolate individual energy components. Specific energy components measured include borehole chambering, elastic deformation (ground vibration), translational and rotational kinetic energy (heave), and air overpressure (air blast). This research was able to account for 73% of the total explosive energy. Borehole chambering (13%), rotational kinetic energy (25%), translational kinetic energy (5%), and air overpressure (28%) were determined to be the largest components. Prior research efforts have largely ignored rotational kinetic energy and have only been able to offer predictions for the values of borehole chambering and air overpressure energies. This dissertation accounted for a significantly higher percentage of total available explosive energy than previous research efforts using novel measurement techniques. It was shown that borehole chambering, heave, and air blast are the largest energy components in a blast. In addition to quantifying specific energy partitions, a basic goal programming objective function was proposed, incorporating explosive energy partitioning and blasting parameters into a framework that can be used for future energy optimization.

Esta pesquisa apresenta o projeto, construção e testes, tanto de laboratório como de campo de um sismógrafo de engenharia para o monitoramento dos níveis de vibração e pressão acústica, resultantes do processo de desmonte de rocha utilizando explosivos. Desenvolveram-se filtros e amplificadores com características que atendam às especificações impostas pelo guia intitulado \"ISEE Performance Specifications for Blasting Seismographs\" (ISEE, 2011), bem como, foram utilizados sensores (geofones e microfone) desenvolvidos e fabricados por terceiros, mas que atendam às características impostas pelo guia. A interconexão entre a etapa analógica com a digital foi realizada através da utilização de módulos de conversão A/D com tecnologia Sigma-Delta e resolução de 24-bits. Todas as etapas de aquisição, processamento e armazenamento de dados são controladas através de um microcontrolador ARM Cortex-M de 32-bits, o qual provê os mais diversos e modernos periféricos. Os testes de laboratório demonstraram a eficácia dos circuitos analógicos, pois apresentaram resposta plana na banda de passagem, onde os filtros passa-baixa, do tipo Butterworth, proporcionaram uma atenuação de 36 dB/oitava a partir da frequência de corte de 500 Hz, enquanto os filtros passa-alta, do tipo passivo, proporcionaram uma atenuação de 6 dB/oitava abaixo da frequência de corte de 2 Hz. Os testes de operação confirmaram a fácil e rápida operação do conjunto sismográfico, enquanto os testes de campo demonstraram a praticidade de sua operação e confiabilidade e coerência dos resultados. Concluiu-se que o sistema é exequível, atendendo às necessidades de monitoramento de um processo de desmonte de rochas utilizando explosivos a um preço relativamente baixo, abrindo a possibilidade de utilizá-lo em monitoramentos permanentes em situações onde isto seja necessário. / This research presents the design, construction and laboratory and field testing of an engineering seismograph for monitoring vibration and acoustic pressure levels during rock blasting. Filters and amplifiers with characteristics that meet the specifications of ISEE Performance Specifications for Blasting Seismographs (ISEE, 2011) have been developed. Third part sensors (geophones and microphones) were selected to attend the characteristics suggested by the guide. The interconnection between the analog and the digital stages was accomplished with A/D conversion modules with Sigma- Delta technology and 24-bit resolution. All data acquisition, processing and storage steps are controlled by a 32-bit ARM Cortex-M microcontroller, which provides several and modern peripherals. Laboratory tests confirmed the effectiveness of the analog circuits that presented flat response between 2 and 500Hz. The low-pass filters developed are type Butterworth with an attenuation factor of 36 dB/octave for frequencies above 500 Hz. The high-pass filters are of passive type with rejection factor of 6 dB/octave below 2 Hz. The operation of the system presented to be easy and fast. Field tests demonstrated its friendliness and the results showed to be consistent. It was concluded that the system is feasible and applicable to monitor rock-blasting process. Its relatively low price opens up the possibility of using it for permanent monitoring in situations where this might be necessary.

Esta pesquisa apresenta o projeto, construção e testes, tanto de laboratório como de campo de um sismógrafo de engenharia para o monitoramento dos níveis de vibração e pressão acústica, resultantes do processo de desmonte de rocha utilizando explosivos. Desenvolveram-se filtros e amplificadores com características que atendam às especificações impostas pelo guia intitulado \"ISEE Performance Specifications for Blasting Seismographs\" (ISEE, 2011), bem como, foram utilizados sensores (geofones e microfone) desenvolvidos e fabricados por terceiros, mas que atendam às características impostas pelo guia. A interconexão entre a etapa analógica com a digital foi realizada através da utilização de módulos de conversão A/D com tecnologia Sigma-Delta e resolução de 24-bits. Todas as etapas de aquisição, processamento e armazenamento de dados são controladas através de um microcontrolador ARM Cortex-M de 32-bits, o qual provê os mais diversos e modernos periféricos. Os testes de laboratório demonstraram a eficácia dos circuitos analógicos, pois apresentaram resposta plana na banda de passagem, onde os filtros passa-baixa, do tipo Butterworth, proporcionaram uma atenuação de 36 dB/oitava a partir da frequência de corte de 500 Hz, enquanto os filtros passa-alta, do tipo passivo, proporcionaram uma atenuação de 6 dB/oitava abaixo da frequência de corte de 2 Hz. Os testes de operação confirmaram a fácil e rápida operação do conjunto sismográfico, enquanto os testes de campo demonstraram a praticidade de sua operação e confiabilidade e coerência dos resultados. Concluiu-se que o sistema é exequível, atendendo às necessidades de monitoramento de um processo de desmonte de rochas utilizando explosivos a um preço relativamente baixo, abrindo a possibilidade de utilizá-lo em monitoramentos permanentes em situações onde isto seja necessário. / This research presents the design, construction and laboratory and field testing of an engineering seismograph for monitoring vibration and acoustic pressure levels during rock blasting. Filters and amplifiers with characteristics that meet the specifications of ISEE Performance Specifications for Blasting Seismographs (ISEE, 2011) have been developed. Third part sensors (geophones and microphones) were selected to attend the characteristics suggested by the guide. The interconnection between the analog and the digital stages was accomplished with A/D conversion modules with Sigma- Delta technology and 24-bit resolution. All data acquisition, processing and storage steps are controlled by a 32-bit ARM Cortex-M microcontroller, which provides several and modern peripherals. Laboratory tests confirmed the effectiveness of the analog circuits that presented flat response between 2 and 500Hz. The low-pass filters developed are type Butterworth with an attenuation factor of 36 dB/octave for frequencies above 500 Hz. The high-pass filters are of passive type with rejection factor of 6 dB/octave below 2 Hz. The operation of the system presented to be easy and fast. Field tests demonstrated its friendliness and the results showed to be consistent. It was concluded that the system is feasible and applicable to monitor rock-blasting process. Its relatively low price opens up the possibility of using it for permanent monitoring in situations where this might be necessary.

Idag finns det ett behov för mer förståelse kring odetonerade sprängämnen i anläggningsindustrin. Dessa sprängämnen som lämnas kvar kan ha förödande konsekvenser och leda till dödsfall. Varför sprängämnen inte detonerar under sprängning kan bero på många faktorer såsom klimat, handhavandefel och fabrikationsfel. Generellt sätt är det farligare i arbeten på ett område där det har sprängts tidigare eftersom det är svårare att förutse farorna.Det saknas en klar rutin kring hanteringen av dessa sprängämnen och befintliga dokument kring kan förbättras.För att få förståelse kring ämnet behövs det studier i åldringsprocess, referensobjekt, hantering och orsaksfaktorer till de odetonerade sprängämnena. Även grundläggande information om hur bergschaktning och sprängning går till är nödvändigt.Trafikverket har därför ett påtalat behov av att skapa en rutin och kartläggning kring problemet.Målet är att underlätta hanteringen, förebygga skador och rädda liv. Odetonerade sprängämnen som detonerat under arbete har orsakat ett antal dödsfall i Sverige. Nollvisionen i byggbranschen kräver att ämnet ska lösas. I denna rapport är målet att skapa en rutin som kan underlätta hanteringen och komplettera nuvarande dokument men även analysera uppkomsten av odetonerade sprängämnen. Med hänsyn till erfarenheter och litteraturstudier ligger denna rapport som grund för fortsatta studier och forskning. / There is a need for higher understanding regarding unexploded ordnance in the infrastructure industry. These explosives that are left behind can have grave consequences and result in the loss of life. Why explosives don`t detonate during blasting may be due to several factors like climate, handling-error or factory errors. Generally, it is more dangerous to work in an area where previous blasting has occurred because it is harder to predict the dangers. There is a lack of routines for handling unexploded ordnance and current documents can be improved.To gain understanding on the matter you need to study aging process, specific cases, handling and possible reasons of unexploded ordnances. Also, basic knowledge about rock removal and rock blasting is required.The Swedish department of transportation (Trafikverket) has a strong need to create a routine and mapping of the issue. The goal is to facilitate handling, prevent damages and save lives.Unexploded ordnance that have detonated during labor have caused several deaths in Sweden.The no deaths vision of the construction industry demands that the problem be solved. In this report the goal is to create a routine and facilitate handling and to supplement current documents but also to analyze the emergence of unexploded ordnance. With regard for past experiences and literature studies this report stands as a foundation for continued studies and research.

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