Mine Surveying

• Drill holes


  Integral to mining operations for gathering subsurface geological data
• Drill holes


  • Play a crucial role in the mining industry as they provide valuable subsurface geological data for exploration, resource estimation, and mine planning
  • Assumptions about their straightness are often incorrect due to deflection, especially in inclined holes
• Deflection of drill holes


  Deviation of the drill hole from its intended path
• Type of drill


  • Diamond drills used in vertical holes may experience more deflection compared to percussion drills due to their design and operation
• Length of drill rods


  • Shorter drill rods in percussion drills may increase the risk of deflection, especially in deeper holes
• Drilling angle


  • Maintaining the desired angle in inclined drill holes can be particularly challenging, especially with diamond drills
• MAAS method


  Utilizes hydrofluoric acid to mark the angle of inclination of a borehole, and a compass to provide directional information
• Gelatine clinometer and compass


  A clinometer is placed in melted gelatine inside a tube to measure the inclination of the drill hole, and a compass provides the direction
• Downhole surveying instruments


  • Specialized instruments designed to be lowered into the drill hole to measure its orientation and deviation from vertical, often utilizing electronic sensors such as accelerometers and magnetometers
• Gyroscopic surveying instruments


  • Use gyroscopes to measure the orientation of the drill hole accurately, maintaining their orientation even when the drill string is rotating
• Magnetic surveying tools


  • Incorporate magnetometers and sophisticated algorithms to compensate for magnetic interference and accurately determine the azimuth of the drill hole
• Solving for strike and dip using boreholes


  Given the locations and depths of three drill holes, the bearing of strike and angle of dip can be determined
• All underground mines shall have at least two (2) interconnected, properly maintained openings to the surface
• Mine opening


  Any opening or entrance from the surface into a mine
• Location of shaft or primary opening


  • Governed by both technical and economic parameters, such as geological, geotechnical, topographical, and hydrological factors, as well as transport effort and ventilation efficiency
• Adit


  Horizontal or near-horizontal tunnels driven into the side of a hill or mountain to access the underground mine workings
• Adit


  • Less energy is required to transport miners and heavy equipment, air current easily enters the mine, and it is easier to drain water by gravity alone
• Incline


  Also referred to as drifts, are mild in inclination usually less than 30 degrees from horizontal and are the most common mode of entry for opening up deposits within a depth of 300 m
• Incline


  • Construction is simpler and cost-effective, maintenance and repairs are easy and cheap, and it is ideal for trackless mining
• Shaft


  A vertical or inclined excavation in a mine extending downward from the surface or from some interior point as a principal opening through which the mine is exploited
• Shaft


  • Takes less time for material transport, can be located at any convenient place, and power cost of ventilation is less compared to incline
• Geological consideration, safety measures, and operational efficiency are key factors in locating a mine plant
• Shaft sinking


  The action of excavating a mine shaft from the top down, where there is initially no access to the bottom
• Shaft sinking process


  Involves preparatory activities, designing, construction, and safety/environmental considerations
• Preparatory activities


  • Site selection and evaluation, geotechnical investigation, and environmental considerations
• Designing


  • Shaft design, stability analysis, and risk assessment
• Construction


  • Site preparation, drilling and blasting, excavation and support, dewatering, and monitoring/quality control
• Safety and environmental considerations


  • Hazard identification, safety protocols, and environmental management
• Shaft sinking


  1. Use explosives to excavate rock and create initial shaft opening

  2. Employ shaft sinking equipment to remove excavated material and install ground support systems

  3. Implement dewatering techniques to manage groundwater and prevent flooding

  4. Continuously monitor ground conditions, excavation progress, and safety parameters
• Blasting techniques


  • Vary depending on the geology and size of the shaft
  • Explosives create high-pressure gas that fractures and crumbles the rock
• Drilling and blasting


  Simple and economical way of accessing underground mineral deposits
• Shaft sinking is a crucial aspect of mining and civil engineering projects, requiring innovative techniques and technologies to ensure efficiency, safety, and cost effectiveness
• Innovative techniques and technologies employed in shaft sinking


  • Blind Boring
  • Shaft Boring Roadheader (SBR)
  • Raise Boring
  • Shaft Freezing
  • Micro tunneling
  • Shaft Jacking
  • Automated Shaft Sinking
• Blind Boring


  • Involves drilling a shaft without any access to the surface
  • Suitable for urban areas or areas with limited surface access
  • Utilizes directional drilling and remote-controlled equipment
• Shaft Boring Roadheader (SBR)


  • Combines the principles of roadheader excavation with shaft drilling
  • Utilizes a roadheader machine equipped with a cutting head to excavate the shaft while simultaneously installing lining segments
  • Efficient and suitable for various ground conditions
• Raise Boring


  • Method used to create vertical or inclined shafts from a lower level to a higher level
  • Involves drilling a pilot hole from the lower level and then reaming it to the desired diameter using specialized raise boring machines
  • Often employed in deep mining operations and underground construction projects
• Shaft Freezing


  • Technique used to stabilize the ground and prevent water ingress during shaft sinking in water-bearing strata
  • Involves circulating a refrigerants such as brine or calcium chloride solution through pipes installed around the perimeter of the excavation
  • Freezes the surrounding ground, creating temporary barrier that allows excavation to proceed safely
• Micro tunneling


  • Trenchless method used for constructing small-diameter tunnels and shafts with minimal surface disruption
  • Involves remotely controlled micro tunneling machines equipped with cutting heads and spoil removal systems
  • Particularly useful for shaft sinking in urban areas or environmentally sensitive locations
• Shaft Jacking


  • Also known as hydraulic jacking or pipe jacking
  • Method used to sink shafts by pushing precast concrete or steel segments into the ground using hydraulics jacks
  • Suitable for relatively shallow shafts in stable ground conditions
  • Offers advantages such as minimal surface disruption and reduced environmental impact
• Automated Shaft Sinking


  • Automation technologies such as robotics, remote controlled equipment, and advanced monitoring systems are increasingly being employed
  • Can perform tasks such as drilling, blasting, excavation, and rock reinforcement with greater efficiency and accuracy than traditional manual methods