How In-Situ Joints Affect Explosive Energy Distribution During Blasting Rock masses in mining and quarrying environments are rarely intact; they are intersected by natural joints, fractures, and bedding planes. These in-situ discontinuities significantly influence how explosive energy is transmitted and utilized during blasting. When properly understood and incorporated into blast design, they can aid fragmentation. However, when ignored, they may lead to inefficient energy usage and poor blast outcomes (See attached Video). Impact of In-Situ Joints on Energy Distribution Explosives generate high-pressure gases intended to create new fractures and displace rock. In a massive, competent rock with minimal joints, most of this energy contributes directly to breakage. However, in jointed rock masses, energy behaves differently. Joints weaken the structural integrity of the rock, providing planes of weakness through which energy can escape. If the existing joints are not accounted for, explosive energy may simply displace in-situ rock blocks along these planes rather than fracture them (See attached Video). Instead of breaking the rock into controlled fragments, the blast may push intact blocks outward, resulting in oversize fragments, back-break, and uneven muck profiles. This inefficiency increases downstream processing costs and reduces overall blast performance. Using WipFrag to Analyze In-Situ Blocks and Joint Orientation Modern photo-analysis tools offer a practical solution for evaluating geological structures before and after blasting. With WipFrag, blasters can take pictures of the bench face to analyze joint orientation and in-situ block conditions. This information is critical for determining the appropriate burden and spacing, especially for the first row of blast holes where rock structure strongly influences burden relief. The WipJoint tool enhances this capability by providing detailed assessments, including: 1. Joint spacing 2. Apparent Joint orientation 3. Rock Quality Designation (RQD) 4. In-situ block size distribution 5. Joint frequency across the face These parameters help blasters understand the structural geology of the bench and design more effective blast patterns tailored to the rock mass. After the blast, blasters can capture images of the muck pile with WipFrag to evaluate how well the fragmentation matches expectations. Comparing pre-blast joint conditions with post-blast fragmentation results allows engineers to refine designs and continuously improve blast performance. Both capabilities are available and fully accessible on WipFrag 4. Download the software here (https://lnkd.in/dAVP7Py9) and create a free account today. Then share your WipFrag username along with a short sentence about what you plan to use the software for, and you could win free demo credits to analyze at least one image at no cost.

Rock Failure and Stress Redistribution in Rock Masses Rock masses exist in a natural state of equilibrium, where in-situ stresses are balanced by the strength and confinement of the rock. Rock failure occurs when this equilibrium is disturbed, causing the stresses within the rock mass to exceed its strength. Such disturbances can result from both natural processes and human activities, particularly in mining, tunneling, and quarrying operations. One common cause of stress disturbance is the creation of a cavity within a rock mass. When material is removed, the original stress field can no longer be maintained, and stresses are redistributed around the opening. This redistribution often leads to stress concentration along the boundaries of the excavation, increasing the likelihood of deformation, cracking, or failure if the rock mass cannot adequately support the new load conditions. Blasting represents a more dynamic and intense source of stress disturbance. Beyond simply removing rock, blasting introduces shock waves, high gas pressures, and ground vibrations that temporarily but significantly alter the stress environment. These stress waves can propagate through the rock mass, activating existing discontinuities such as joints, bedding planes, and faults. The reduction in confinement and the weakening of these structural features can substantially reduce rock mass stability. As stresses are redistributed and confinement is lost, rock faces may experience sliding, spalling, or collapse. In slopes and open excavations, this can manifest as rock falls or planar and wedge failures, particularly where geological structures are unfavorably oriented. The risk of failure is further influenced by rock quality, in-situ stress conditions, blast design, and the proximity of excavations to free faces. Understanding the relationship between stress redistribution and rock failure is critical for safe and efficient rock engineering. Proper excavation sequencing, controlled blasting techniques, and continuous monitoring of rock mass response are essential measures to manage stress-induced instabilities. By accounting for these factors, engineers can minimize the risk of rock failure and maintain the long-term stability of rock structures. The video shared by Bernard Saw as attached to this post clearly demonstrates how excavation activities can trigger rock failure. As material is removed from the rock mass, the natural stress equilibrium is disturbed, forcing stresses to redistribute around the newly created opening. When the rock mass is unable to accommodate these changes, instability develops, resulting in cracking, sliding, and eventual failure of the rock face. The video provides a practical visual example of how excavation-induced stress changes can directly compromise rock mass stability.

[PT] Esta tese propõe sistemas de perigo e risco para taludes de mina usando PCA + discriminante, regressão logística e uma árvore de decisão para consequências, com base em 88 taludes. Introduz um gráfico de perigo (distância de Mahalanobis) e uma matriz de risco que facilitam comunicação entre engenharia e gestão. Os métodos são rápidos e aplicáveis a minas de diferentes portes, apoiando priorização de medidas. O resultado é um processo mais objetivo e rastreável de tomada de decisão. [EN] This thesis proposes hazard and risk systems for mine slopes using PCA + discriminant, logistic regression, and a decision tree for consequences on 88 slopes. A hazard plot (Mahalanobis distance) and a risk matrix make communication between engineering and management easier. The methods are fast and deployable across mine sizes, supporting prioritisation of actions. The result is a more objective and traceable decision-making process.

[PT] A dissertação classifica taludes de mina como estáveis ou instáveis usando um conjunto com 84 taludes e 18 variáveis geotécnicas. Combina PCA, boosting e discriminante de Fisher, alcançando alta acurácia com erro mínimo de falsos “estáveis”, o que é crucial para segurança operacional. O fluxo é objetivo e reprodutível, adequado para triagem rápida de risco e priorização de inspeções de campo. Os resultados mostram que pequenos bancos de dados bem curados já permitem decisões confiáveis quando aliados a técnicas multivariadas. [EN] This MSc work classifies mine slopes as stable or unstable from a dataset of 84 slopes and 18 geotechnical variables. It blends PCA, boosting, and Fisher’s discriminant, achieving high accuracy with negligible “unsafe-as-safe” errors—vital for operational safety. The workflow is straightforward and reproducible, ideal for fast risk screening and field-inspection prioritization. Findings show that small, well-curated datasets can support reliable decisions when combined with multivariate methods.

This research paper studies and compares two popular rock classification systems — Rock Mass Rating (RMR) and the Tunneling Quality Index (Q-system) — which are very important for designing safe and stable tunnels. When engineers build tunnels underground, they need to understand the condition of the surrounding rocks. Some rocks are strong and stable, while others are weak and may collapse if not supported properly. The RMR and Q-systems help engineers measure rock quality, identify possible risks, and choose the best support methods such as rock bolts, shotcrete, steel ribs, or concrete lining. The study uses real tunnel projects to test both systems and see how accurate they are in predicting rock stability and support requirements. It also discusses the advantages and limitations of each system. The RMR system is easier to apply and gives quick results, making it suitable for simple projects. On the other hand, the Q-system is more detailed and works better in complex geological conditions where more precision is needed. The paper concludes that both systems are useful, but the best choice depends on the type of rock, tunnel depth, and construction method. Understanding these systems helps engineers make better design decisions, reduce risks of tunnel failure, and save time and money during construction. In simple terms, this research shows how science and engineering come together to make underground tunnels safer and more reliable for people and industries.

[PT] O trabalho simplifica a tarefa para duas classes (estável/instável) e melhora o acerto da rede neural mesmo com poucas amostras. Ele discute tempo de processamento, facilidade de entender o modelo e entrega um app simples para uso prático. O resultado é um fluxo direto para classificar taludes rapidamente e com apoio visual. Bom para equipes de campo e gestores. [EN] This study simplifies the task to two classes (stable/unstable) and improves a neural network’s accuracy with small datasets. It discusses compute time, interpretability, and ships a simple app for practical use. The result is a straightforward way to classify slopes quickly with visual support. Handy for field teams and managers.

[PT] O trabalho aplica aprendizado de máquina para dizer se um talude está estável ou instável. Ele monta um pequeno conjunto de dados com variáveis escolhidas por especialistas, treina o modelo e confere o resultado. A ideia é ganhar velocidade na triagem de riscos, em vez de depender só de métodos tradicionais. É útil para minas próximas a comunidades e para órgãos públicos que precisam de respostas rápidas. [EN] This report applies machine learning to classify slopes as stable or unstable. It builds a small expert-curated dataset, trains the model, and checks results. The goal is to speed up risk screening instead of relying only on traditional methods. It’s useful for mines near communities and for public agencies needing quick decisions.

Open pit mining is one of the most common and cost-effective methods used to extract valuable minerals from the earth. It’s like digging a giant bowl-shaped hole in the ground — layer by layer — to reach the desired ore. But behind this massive excavation lies the critical role of a Geotechnical Engineer — often working silently in the background to keep everything stable, safe, and efficient. 🧠 So, what exactly does a Geotechnical Engineer do in open pit mining? Let’s break it down with simple examples: 🪨 1. Slope Design & Stability Imagine cutting a big slice out of a cake. If the sides are too steep, it collapses. In mining, we design pit walls (slopes) that are stable enough to stand safely while also allowing the maximum amount of ore to be recovered. 📌 We study: Rock and soil strength Water pressure in the ground (pore pressure) Discontinuities (like fractures or faults) 🛠 Tools like limit equilibrium analysis, finite element modeling, and slope monitoring systems help us make decisions. 🌧️ 2. Water Control Water is a major enemy of open pit stability. 💧 Scenario: During heavy rain, water can seep into the pit walls, weaken the rock, and trigger landslides. ✅ Geotechnical Engineers design drainage systems, dewatering wells, and piezometers to manage groundwater and prevent failures. 🏗️ 3. Rock Mass Classification Every rock behaves differently under stress. We classify the rock mass using systems like: RMR (Rock Mass Rating) Q-System GSI (Geological Strength Index) 📌 This helps in selecting: Support systems (bolts, mesh) Slope angles Excavation methods 🚧 4. Monitoring & Risk Management We don’t stop after design — we monitor pit walls continuously. 📡 Using instruments like: Inclinometers Extensometers Prism monitoring with total stations Drone-based LiDAR and photogrammetry 📈 This allows us to detect movements early and warn the operations team before a slope failure occurs. 🛑 Real-Life Example: At a gold mine in a mountainous area, unexpected rainfall can cause slope instability. The geotechnical team may install piezometers and modify the pit slope angle. This timely intervention can prevent a major failure and save millions in lost ore and equipment. 💼 Whether it’s copper in Chile, gold in Ghana, or phosphate in Saudi Arabia — open pit mining cannot operate safely without geotechnical expertise. 👉 A small misjudgment in slope angle can result in catastrophic slope failure, risking lives, equipment, and production.

[PT] A dissertação investiga o fluxo de materiais granulares por três frentes complementares: um modelo matemático a partir de EDPs, um modelo experimental em escala reduzida (silo) e um modelo numérico via Método dos Elementos Discretos, usando gnaisse britado em faixas granulométricas distintas. As abordagens foram comparadas para gerar um banco de dados e compreender fenômenos como formação de arco, vazão e velocidade de fluxo, culminando em padrões de comportamento associados à razão abertura/diâmetro de partícula. O trabalho entrega um caminho prático para transformar caracterização física e simulação em decisões de projeto e operação. [EN] This MSc thesis studies granular flow through three complementary approaches: a mathematical model from governing PDEs, a reduced-scale experimental setup (silo), and a numerical model using the Discrete Element Method, with crushed gneiss across different size classes. The methods are cross-validated to build a data bank and to understand effects such as arching, discharge rate, and mean velocity, leading to behavior patterns tied to the aperture/particle-size ratio. The work provides a practical bridge from physical characterization and simulation to engineering design and operations.

[PT] Este artigo apresenta um método analítico para calcular volumes de blocos rochosos em maciços fraturados usando dados simples de campo (orientação de descontinuidades e uma dimensão linear), aplicável a blocos tetraédricos, prismáticos/tabulares e com extensão a poliédricos. A proposta supre lacunas dos modelos tradicionais ao exigir entradas mais realistas, tornando o dimensionamento de contenções e a avaliação de estabilidade mais ágil e reprodutível em obras de mineração e túneis. É leitura útil para quem precisa transformar mapeamentos geotécnicos em decisões práticas de projeto. [EN] This paper introduces an analytical method to compute rock-block volumes in jointed masses using field-friendly inputs (discontinuity orientations plus one linear size), covering tetrahedral and tabular/prismatic blocks and extending to polyhedra. It overcomes limitations of classic approaches by requiring more realistic data, enabling faster, reproducible support design and stability checks for mining and tunneling projects. A concise, practical bridge from geotechnical mapping to engineering decisions.

[PT] O estudo aplica as classificações geomecânicas RMR, Q e RMi em um maciço de xisto localizado em uma encosta na rodovia dos Inconfidentes, próxima a Ouro Preto. Foram identificados dois setores com diferentes graus de intemperismo; o setor 1 é altamente alterado e apresenta falhas por material e grande quantidade de detritos, enquanto o setor 2 é menos alterado e apresenta falhas em blocos. O artigo discute dificuldades na obtenção de parâmetros geotécnicos, como a influência do intemperismo na resistência medida com o martelo Schmidt, e utiliza as classificações para estimar propriedades de resistência e deformabilidade do maciço. [EN] This study applies the RMR, Q and RMi geomechanical classifications to a schist rock mass on a slope along the Inconfidentes highway near Ouro Preto. Two distinct sectors were identified: Sector 1 is highly weathered with material failures and abundant debris, while Sector 2 is less weathered and exhibits block failures. The paper addresses challenges in obtaining geotechnical parameters—such as the influence of weathering on unconfined strength measured by Schmidt hammer—and uses the classifications to estimate the rock mass strength and deformability.

[PT] O artigo discute métodos analíticos e numéricos para analisar o tombamento de blocos em taludes rochosos, ressaltando que mecanismos de deslizamento são bem conhecidos, mas que o tombamento é pouco estudado na prática de engenharia. Muitas abordagens analíticas exigem simplificações exageradas da geometria das descontinuidades e do talude, e os modelos numéricos adequados precisam representar explicitamente as descontinuidades. O trabalho apresenta as vantagens e limitações de diferentes métodos, tanto contínuos quanto descontínuos, para estudar o tombamento de blocos. [EN] This paper examines analytical and numerical approaches to study block toppling in rock slopes, noting that sliding failures are well understood but toppling is less common in engineering practice. Many analytical solutions oversimplify the geometry of discontinuities and slope, and numerical models must represent the discontinuities to capture toppling mechanisms. The authors discuss the advantages and limitations of various continuous and discontinuous methods for modelling block toppling.

[PT] O cálculo de volumes de blocos em maciços rochosos fraturados é essencial na mineração subterrânea para o dimensionamento de contenções como tirantes e telas. Este trabalho apresenta uma solução analítica geral para calcular volumes de blocos de diferentes formas, aliada a uma abordagem probabilística que define a população de blocos a partir de dados de mapeamento geotécnico. A metodologia inclui implementação em Mathcad e Excel e gera uma curva de distribuição volumétrica dos blocos, possibilitando otimizar projetos de contenção tanto economicamente quanto em termos de segurança operacional. [EN] Calculating block volumes in jointed rock masses is fundamental for designing support systems in underground mining. This paper introduces a general analytical solution that accommodates wedge‑shaped, tabular or prismatic blocks and integrates a probabilistic approach to characterize block populations using geotechnical mapping data. A computational implementation produces a volumetric distribution curve, enabling optimized support design by balancing cost efficiency and operational safety.

[PT] O estudo avalia diversos métodos analíticos e numéricos para investigar a ruptura por tombamento de blocos em taludes rochosos. Destaca-se que modelos existentes apresentam limitações práticas porque exigem dados geométricos detalhados difíceis de obter em campo e a aplicação de métodos computacionais ainda não é trivial. O artigo compara as vantagens e limitações de diferentes abordagens analíticas e numéricas para modelar esse mecanismo de falha. [EN] This paper reviews analytical and numerical methods for studying block‑toppling failures in rock slopes. Existing analytical models are difficult to apply in practice due to the detailed geometry required and computational approaches must treat the rock mass as a discontinuous medium. The authors analyse various methods, discussing their respective strengths and limitations in representing toppling mechanisms.

[PT] Este trabalho relata um estudo de caso sobre a falha de um bloco rochoso em uma encosta urbana em Ouro Preto, utilizando projeções hemisféricas inclinadas para identificar o mecanismo de ruptura. Foram analisadas duas condições: apenas carregamento gravitacional e a combinação de carregamento gravitacional com pressão de poros nas descontinuidades. A metodologia inclui uma solução analítica para obter a geometria precisa do bloco antes de aplicar os métodos de equilíbrio limite. [EN] This case study examines a rock block failure in an urban slope in Ouro Preto, Brazil. Kinematic analyses using inclined hemisphere projections on the slope face were carried out to determine the failure mechanism. Two situations were considered—purely gravitational loading and gravitational loading plus pore pressure—and an analytical procedure was used to compute the block geometry for stability analysis.