Underground reservoirs in coal mines, consisting of goafs (By goaf, we mean the space that remains underground after extraction valuable minerals), are commonly utilized for mine water storage and drainage, with their primary load-bearing structures being “roof–coal pillar” systems. Consequently, this structure must endure repeated immersion behavior resulting from fluctuations level, risk geological disasters. This paper analyzes variation mechanical properties sandstone–coal composite...

Predictive model and formula of jacking force has been well-established for circular pipe in the past decades. However, frictional mechanism pipe–soil–slurry prediction rectangular not well understood. Nowadays, is widely used, because its over 20% larger effective usable area than that as underground facilities, with same cross-sectional area. Nevertheless, corresponding models thrust are lacking. In order to further understand slurry jacking, five classical analytical calculation have...

Soil water erosion is frequently reported as serious problem in soils Southeast Asia with tropical climates, and the variations pH affect development of erosion. This study investigated effects changes on soil based physical properties simulated adjusted from 2.0 to 10.0 through artificial rainfall tests. The zeta potential was entirely shifted positive direction at each condition due Al, Ca, Mg. In range 6.0 2.0, aggregation particles resulting release Al3+ clay minerals and/or molecular...

Bulking characteristics of gangue are great significance for the stability goafs in mining overburden caving zones. In this paper, a particle discrete element method with clusters to represent was adopted explore bulking coefficient time effect broken rock zone under three-dimensional triaxial compression condition. The phenomena stress corrosion, deformation, and failure blocks were simulated numerical model. Meanwhile, new criterion fragments damage put forward. It found that has obvious...

During pipe-roof construction using pipe-jacking technology, lubricants are injected into the tail void to reduce pipe–soil friction and minimize soil loss. However, research on ground settlement caused by multiple adjacent pipe jackings remains limited, influence of lubricant Young’s modulus control is not clear. To address these gaps, this study conducts a comprehensive investigation Fast Lagrangian Analysis Continua in 3 Dimensions (FLAC3D). Initially, model validated against case Japan....

Stability of the retained goaf-side gateroad (RGSG) is influenced mainly by movements roof strata near coal seam after coalface passes by. To make effective controlling technology for stability RGSG, we analyze structure over RGSG to illustrate mechanism causing instability under different conditions. We then examine dynamic evolution deformation and abutment stress in rock surrounding during mining, using FLAC3D numerical software reveal characteristics Next, corresponding technologies...

This paper presents an alternative methodology for the study of flyrock hazards in mining, utilizing Artificial Intelligence (AI) through machine learning by classification. By using distance as a delineator to denote consequences blast, models generated two classes blasts: safe and unsafe. In this study, statistical best suited classification, that is, K Nearest Neighbors (KNN), Support Vector Machine (SVM), Decision Tree (DT), Neural Networks (ANNs), were used, their classification...

Abstract Underground Coal Gasification (UCG) requires monitoring of the gasification area because process is invisible and reaction temperature exceeds 1000 °C. Many fracturing events that occurred due to coal heating can be captured with Acoustic Emission (AE) technique during UCG. However, conditions generate UCG have not yet been clarified. Therefore, experiment small-scale are conducted by measuring AE activities in this research examine applicability instead measurement as a method As...

Blasting remains as an economical and reliable excavation technique, but there are some environmental shortcomings such the control of blast-induced vibration. The impacts vibration over surrounding communities in a blast area have been investigated for decades researchers using myriad empirical predictive attenuation equations. These models, however, may not satisfactory accuracy, since parameters associated to geomechanical properties geology affect propagation seismic waves, making...

In Japan when urban infrastructures need to be constructed, the difficulty of utilizing t he ground or shallow strata will necessarily lead more frequent use deep strata. The common construction methods are open-cut, pipe jacking, and shield methods.In recent years a new jacking method has been established that can adap ted 20 m below more. Using method, drivage machine continue move an underground until completion driving. Therefore over-cutting area (so-called tail-void) must formed lower...

In the drilling processes of machine tools an increase speed is usually required, but it often leads to breakage drill due excessive torque. Thus necessary measure and control cutting torque in real time. this study a new sensorless system developed irrespective wear material target work-pieces. The authors (1994) proposed estimation method for using disturbance observer. This paper concerned with PID process based on estimated information. Experimental results demonstrate effectiveness method.

The size distribution of fragmented rocks depends on not only the blasting standard but also mechanical properties, joint system and crack density rock mass. As, especially, cracks in mass are heavily developed at limestone quarries Japan, joints and/or have big impacts effects such as rocks. Therefore, if can be known evaluated quantity, operation done more effectively, efficiency safety. However, guideline for designing appropriate based condition cracks, discontinuities, from scientific...

Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting designed process plays an indispensable role these industries, it can also have multiple adverse environmental impacts. One such effect flyrock, which poses risks nearby machinery, residential structures, even lead injuries or fatalities. To optimize efficiency as well restrict side effects, prediction of blast aftereffects vital....

Accurate estimation of the mean fragment size is crucial for optimizing open-pit mining operations. This study presents an approach that combines clustering, hyperparameter optimization, and data augmentation to enhance prediction accuracy using Xtreme Gradient Boosting (XGBoost) regression model. A dataset 110 blasts was divided into 97 training testing, whereas a separate set 13 new, unseen used evaluate robustness generalization Hierarchical Agglomerative (HA) K-means clustering...

Soil erosion is one of the major environmental problems in open-cut mines tropical regions. It causes negative impacts including removal nutrient-rich topsoil, destroys aquatic habitat, dam and pond siltation, clogs river by deposition sediment, water pollution rehabilitation process. texture an important factor to affect soil erosion. In this study, artificial rainfall experiment laboratory scale was conducted clarify mechanism under different composition discuss methods for minimizing The...

In Japan when urban infrastructures need to be constructed, the difficulty of utilizing ground or shallow strata will lead a more frequent use deep strata. The common construction methods are open-cut, pipe jacking, and shield methods. recent years, new jacking method has been established that can adapted 20 m below more. Using this method, drivage machine continue move an underground until completion driving. Therefore over-cutting area (so-called tail-void) must formed lower friction...

A new method is proposed for in-process detection of torque working on a drill. In this method, can be directly detected from drill itself, which, in principle, allows quick dynamic response. Static experiments were carried out to investigate fundamental characteristics. The possibility was demonstrated experiments. Prototype sensors solenoidal design showed promising results.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>