There was a time when the city required rock drilling services, Melbourne also experience a major shutdown. Roads were closed and services are suspended. There was an ugly trench cut through the surface. But those days are gone now. With the use of trenchless techniques, precisions drill technology is utilised to make tunnels that leave the surface almost completely undisturbed.
Victoria Trenchless Solutions is a leading name in this field. They are working with and for some of Australia’s biggest corporate names and local government over the last 22 years on various projects. These include communication, electrical and utilities supply upgrades.
When hiring a contractor for rock drilling in Melbourne, there must be some key points to consider. Written below are just a few of them.
1. Type of Operation
When it comes to rock drilling, Melbourne has seen several types of trenchless drilling techniques used, including:
● HAB, or Horizontal Augur Boring, where a straight tunnel is drilled from one
● Pipe Ramming, where a steel casing is installed using a percussion hammer
● Pipe Jacking, where a pipes are installed as a continuous string directly behind a shield machine, using hydraulic jacking techniques
● HDD, or Horizontal Directional Drilling, used to lay conduits, cables and plastic piping through a shallow arc tunnel drilled from the surface. A reamer is used to widen the tunnel to the required size.
● Pipe Bursting, where old pipes are broken up by a drill and replaced by a new plastic piping.
● Micro-tunneling, where narrow tunnels are drilled with the help of precise micro-technology (laser-targets destinations)
2. Ground Conditions
While the techniques used when rock drilling in Melbourne can vary, the soil or rock type has a definite influence on the choice of drill bit or blade that is chosen for the job. The different types of ground condition range from:
● Hardpan, found just under the top-soil, can be so compact it is impervious to water
● Soft Rock includes shale and siltstone
● Medium Rock like danstone, limestones and other types of marble and granite
● Hard Rock includes quartzite, basalt, granite and siliceous limestone
● Very Hard Rock, includes taconite and rhyolite
3. Types of Drill Bits
So, what are the rock drills and drill bits (heads) that need to be considered when planning rock drilling in Melbourne?
● Drilling Blades – The blade of a drill bit has an obvious impact on the efficiency of the drilling project. They need to be made of tungsten carbide, one of the toughest materials known to man. That makes them ideal for cutting through hard pack clay, mixed soil and rocky soils.
● Slant-Face Bits
● Flat or Bent Spade – This type of drill bit head is suitable for clay, sand and organic soils. These can be modified for hard or compact grounds
● Rock Bit – This is for soft to medium rock and hard pan ground
● Rotary Rock Bits
● Drag Bit – This is one of the most popular and reliable options. It is ideal for sands, clays and soft rock conditions. It usually have short blade that cut rapidly through the ground,
● Roller Bit – This is the favoured option for cutting through medium to hard rocks. It gets its name from the cones (usually 3), tipped with tungsten carbide inserts that ‘roll’ rapidly and effectively crush and grind out the rock. A good choice for back reaming to expand the tunnel width.
● Reamer Bit – This is used in sandy soils or wet clay. It is a hardened cutting surface attached to drill pipe and is used to widen the borehole. The Roller or Drag bit that is fitted in front helps keep the borehole straight during the reaming process.
● Percussive Bits (with hammer drill)
● Eccentric Flat Faced – With carbide button inserts added, it can handle soft to hard rock
● Carbide Button Slant Faced and Round Faced – These are excellent for soft to hard rock and on hardpan ground.
Victoria Trenchless Solutions
Over the years, we have worked on many projects involving soft and hard rock drilling in Melbourne. Specialists in Trenchless technologies, we have a track record of drilling the Victorian landscape in a manner that maximises the use of technology while minimising disruption. So, it could ease both social and environmental concerns.
For more details on our services in rock drilling in Melbourne and elsewhere, visit our website or contact us directly at (03) 9795 0608.