The easiest and cheapest of drilling methods. Unmatched ease for short distance and small diameter holes.
Basic description: The impact mole’s pneumatic hammer functions as a broach. It presses the soil material to the side, creating a hole in the ground. A plastic pipe – carried by the tool – is inserted.
Used in: Gravel, sand and dry clay
Limitations: Large rocks, bedrock, loose clay, sub-groundwater levels
Launch pit: Small pits. No thrust support needed
Used for: Conduit pipes for power, fiber, water, gas
Excellent and reliable method for gravel, and soil with rocks and boulders. See also Rock drilling below.
Description: The pneumatic DTH-hammer allows the drill bit to crush the material in its way. The outer ring bit pulls a steel casing, which keeps the hole open and functions as a conduit pipe after competed drill. Cuttings are transported out through the casing.
Used in: All soil types, and bedrock
Limitations: None in terms of geotechnology
Launch pit: Provides room for drilling equipment, ranging from 3×7 m
Pipe length, diameter and material: 0-80 m, 100-1200 mm, steel
Used for: Conduit pipes for power, fiber, gas, district heating, pressurized wastewater, as well as gravity sewers for waste- and storm water.
Used for somewhat larger pipes under roads, railways and more. Primarily developed for clay and sand.
Description: The pneumatic hammer drives the pipe into the soil, “punching” out a hole. The pipe is emptied after the entire pipe is through.
Used in: Clay and sand
Limitations: Larger rocks, bedrock
Launch pit: Provides room for drilling equipment, ranging from 3×10 m. Thrust support not needed.
Pipe length, diameter and material: 0-50 m, 300-1500 mm, steel
Used for: Conduit pipes for power, fiber, gas, district heating, water, sewer force mains, and gravity sewers for waste- and storm water.
Used for conduit pipes under for example roads and railways. Primarily developed for clay and sand.
Description: The conduit pipe is pushed into the soil. The pipe is emptied parallel with the drilling process by a large screw placed inside the pipe.
Used in: Clay and sand
Limitations: Larger rocks, bedrock
Launch pit: Provides room for drilling equipment, ranging from 4×10 m. Thrust support needed.
Pipe length, diameter and material: 0-50 m, 300-1200 mm, steel
Used for: Conduit pipes for power, fiber, gas, district heating, water, sewer force mains, and gravity sewers for waste- and storm water.
Amazing technology that enables the drilling of long and curved holes. Primarily developed for clay and sand.
Description: The pilot rod is drilled through the ground according to a projected bore alignment. The direction of the drilling bit is controlled with the help of a radio transmitter in the bit itself, and steered by a steering tool ahead. As the rod is reversed, the hole is reamed out and the pipe is inserted into the hole.
Used in: Mainly clay and sand
Limitations: Gravel, rocks and bedrock
Launch pit: Only needs small launch- and receiving pits
Pipe length, diameter and material: 0-1000 m, 40-1000 mm, plastic, steel, MG ductile iron
Used for: Conduit pipes for power, fiber, gas, district heating, water, sewer force mains, and gravity sewers for waste- and storm water.
Similar to HDD, the difference being that this method can be used in more challenging soil.
Description: The pilot rod is drilled through the ground according to a projected bore alignment. The rotary drill head is made to rotate by an internal shaft, grinding the material in its way. The drill head is steered by altering the angle of the outer drilling rod, and tracking is allowed through a built-in transmitter. The hole is reamed out and pipe inserted as the rod is reversed.
Used in: Frictional soils and clay, stony hard ground, including bedrock
Limitations: Larger dimensions in swiftly shifting soil materials
Launch pit: Needs only a smaller launch- and receiving pit
Pipe length, diameter and material: 0-300 m, 100-500 mm, plastic, steel
Used for: Conduit or service pipes for power, fiber, gas, district heating, water and sewer force mains.
Used for installing concrete pipes in clay material. Projects often concern gravity sewers for waste- and storm water, with a small incline.
Description: The concrete pipe is pushed into the clay by the force of hydraulic cylinders. A steering tool as placed at the front, correcting for deviations from the straight bore alignment. Clay material is extracted from the pipe as the drilling proceeds, using a conveyor, slusher or by flushing etc.
Used in: Clay
Limitations: Frictional soils
Launch pit: Provides room for drilling equipment, ranging from 2×2 m. Thrust support needed.
Pipe length, diameter and material: 0-200 m, 400-2500 mm, concrete
Used for: Gravity sewers for waste- and storm water.
Used for installing concrete pipes. The method is similar to pipe jacking, but can be applied in all kinds of material, even solid rock. Often used for gravity sewers with a small slope, but also for installing conduit pipes for water, cable culvert and more.
Description: The concrete pipe is pressed into the soil using hydraulic cylinders. Drilling and steering tools are placed at the front of the drill head. The drill head makes the soil penetrable, and a crusher cone grinds the fragments. Cuttings are extracted along with the drilling fluid in a closed system to a drill fluid separator placed above ground.
Used in: Clay, sand, gravel, block, boulder and solid rock
Limitations: None in terms of geotechnology
Launch pit: Provides room for drilling equipment, ranging from 2×2 m. Thrust support needed.
Pipe length, diameter and material: 0-1000 m, 250-4200 mm, concrete
Used for: Waste- and stormwater tunnels. Also as conduit for power, fiber, gas, district heating, and water and sewer force mains.
A fast and reliable method for moderate lengths and dimensions.
Description: The pneumatic drill bit crushes and pulverizes the rock. The method is similar to techniques used for drilling wells but offers much higher precision. When the pilot hole is completed, the hole is reamed out in one or several steps to achieve the wanted dimension. The reamer bit resembles a pilot bit connected to a steering rod.
Length, diameter: 0-150 m, 100-400 mm
Used for: Channels for power, fiber, gas, district heating, water, sewer force mains, as well as gravity sewers for waste- and storm water.
A very fast method for longer holes that require steering. Straight or curved.
Description: The pneumatic drill bit crushes and pulverizes the rock. The method is similar to regular HDD but is here especially adapted to drilling in solid rock. When the pilot drilling is completed, the hole is reamed out in one or several steps to achieve the wanted dimension. The reamer bit, equipped with hard-metal rolls, grinds the rock as it is pulled back through the pilot hole.
Length, diameter: 0-300 m, 100-400 mm
Used for: Channels for power, fiber, gas, water, sewer force mains
Method for large holes in solid rock.
Description: A pilot hole is created using for example a rotary drill bit (e.g. All Terrain, see soil drilling methods), hammer drilling or core drilling. When the pilot hole is completed, it is reamed out to the wanted dimension in one step. The reamer bit, equipped with hard-metal rolls, grinds the rock as it is pulled back through the pilot hole.
Length, diameter: 0-1000 m, 600-4000 mm
Used for: Channels for power, fiber, gas, district heating, water, storm- and wastewater. Connections to storm- and wastewater tunnels, mining shafts and power plant tunnels.
Precision drilling for pilot holes or for geological investigation.
Description: A hollow, rapidly rotating drill pipe is used, with a diamond drill bit, which cuts out a core through the rock.
Length, diameter: 0-2000 m, 40-100 mm
Used for: Pilot drilling for reaming with a complementary method, as well as geological investigation.
Microtunneling is commonly used for drilling concrete pipes, see also Microtunneling for boring in soil, but the method could also be suitable for boring in solid rock as an alternative to a tunnel blasting.
Description: Boring- and steering tools are placed at the front of the drill head. Hard metal cutters in the drill head breaks down the solid rock, and a crusher cone grinds the fragments. Cuttings are extracted along with the slurry fluid in a closed system to a slurry fluid separator placed above ground or with a conveyer belt. Concrete pipes behind the drill head push the drilling equipment forward. New concrete pipes are installed at the hydraulic cylinders of the jacking station as the boring proceeds.
The drilling equipment may also be used without pipes, using grippers to press against the bedrock and advance the machine forward or pushing against segment lining installed behind the machine to advance forward.
Pipe length, diameter: Microtunneling 0-1000 m, 1200-4200 mm. TBM 0-10,000 m, 1200-19,000 mm
Used for: Waste- and stormwater tunnels. Also for traffic tunnels for road and railway, conduit for power, fiber, gas, district heating, water and pressurized wastewater.
Fast and easy technique for rehabilitation of pressure pipelines by inserting a pipe of smaller dimension into the existing pipeline.
Description: A new “carrier” plastic pipe is welded together and pulled into the existing “host” pipe with a winch. The annular space between the carrier and host pipes can be filled out with concrete (grouted).
Existing pipe: All types
Space for installation: Insertion pit for the new pipe
Pipe length, diameter and material: 0-1000 m, 50-1000 mm, plastic
Used for: Water and sewage, gas
Pipeline rehabilitation through inserting a pipe of smaller dimension into the existing pipeline. A continuous pipe with a momentarily reduced cross-sectional area is installed into the existing, while regaining normal dimension after installation. Annular space between old and new pipe is minimal.
Description: A new plastic pipe is reshaped at the worksite or folded already at the factory. After installation, the new pipe regains its original shape through added pressure and heat, normally water vapor.
Existing pipe: All types
Space for installation: Manhole or insertion pit for installing the new pipe
Pipe length, diameter and material: 0-1200 m, 100-1000 mm, plastic
Used for: Water and sewage, gas
Bursting carrier pipe for installing a new pipe. The new pipe may be of the same size as the host, or larger.
Description: A hydraulic pulling equipment allows the expander head to break down the existing pipe, while at the same time pulling with it a new pipe, replacing the existing. The equipment may carry a cutting tool to ensure easier bursting of the existing pipe.
Existing pipe: Concrete, ceramics, plastic, cast- or ductile iron, steel
Space for installation: Launch pit provides room for equipment, ranging from 2×2 m
Pipe length, diameter and material: 0-150 m, 50-800 mm
Used for: Water and sewage, gas
Method for bursting an old pipe and installing a new pipe. The new pipe could have the same dimension as the existing, or larger. This pneumatic method is the predecessor to the hydraulic bursting technique.
Description: The pneumatic hammer allows the expander head to crack and expand the existing pipe, while at the same time pulling in a new pipe. The equipment is pulled with a winch.
Existing pipe: Concrete, ceramics, plastic, cast iron
Limitations: Not suitable in surroundings that are sensitive to vibrations. Oil in the compressed air (used for lubrication) may contaminate the pipe.
Space for installation: Launch pit provides room for equipment, ranging from 2×2 m
Pipe length, diameter and material: 0-150 m, 50-600 m, plastic
Used for: Water and sewage, gas
A reinforced flexible liner, impregnated with thermosetting resins, is inflated and set in place in the existing pipeline.
Description: The flexible line is made up of felt or fiberglass, impregnated in polyester resins. The liner, which is coated in a protective foil on the in- and outside, is pulled into the existing pipe, or folded in by the force of water, compressed air or steam. Once in place, the liner is cured with UV-light, hot water or compressed air.
Existing pipe: All types
Space for installation: Manhole for installation of lining
Pipe length, diameter and material: 0-500 m, 100-3000 m, polyester reinforced or not
Used for: Water and sewage
Lateral pipes: Lateral pipes may be cured from inside the pipe using a so-called hat-profile made of flexible lining, installed by robot.
Pipe rehabilitation through installing a pipe of smaller dimension inside existing pipe. Pipe length ranging from 0,5-6 m.
Description: A new short pipe is placed in existing manhole or launch pit. Each short pipe is pushed into the host pipe in turn. The annular space between carrier and host pipe is filled with concrete (grouted).
Existing pipe: All types
Space for installation: Manhole or launch pit for installation of short pipes.
Pipe length, diameter and material: 0-500 m, 100-2000 m, plastic, reinforced plastic
Used for: Water and sewage
Rehabilitation of large pipes through the installation of a new pipe of smaller dimension into the host pipe. The new carrier pipe is assembled in halves or parts of a pipe segment.
Description: A new segment is installed via existing manhole or from a launch pit. Each segment is assembled in its place, successively building up the new pipe. The annular space between carrier and host pipe is filled with concrete (grouted).
Existing pipe: All types
Space for installation: Manhole or launch pit for installation segments.
Pipe length, diameter and material: 0-100 m, 800-2500 m, reinforced plastic, concrete
Used for: Water and sewage
Restoring a corrosion resistant barrier in pipes.
Description: Mortar is sprayed onto the inside surface of the pipe, using a rotary nozzle.
Existing pipe: Steel, cast- or ductile iron
Space for installation: Launch pits for equipment
Pipe length, diameter and material: 0-300 m, 200-2000 mm, concrete
Used for: Water and sewage
Restoring internal corrosion resistant barrier in pipes.
Brief description: Epoxy- or PU is sprayed onto the inside surface of the pipe, using a rotary nozzle.
Existing pipe: Steel, cast- or ductile iron
Space for installation: Launch pits for equipment
Pipe length, diameter and material: 0-150 m, 100-1000 mm, Epoxy, PU (polyurethane)
Used for: Water and sewage
