Rolkon is a trenchless construction specialist with a team of skilled drillers and operators who together have over 50 years of drilling experience and civil engineering specialisation. These skills are brought to bear using precision machinery and specialised technology which allows Rolkon to deliver practical and efficient solutions such as those described under our Key Projects.
Horizontal Directional Drilling (HDD)
Horizontal Directional Drilling (HDD) is a steerable trenchless method of installing underground pipelines and utilities in a prescribed path bore (straight or curved) by using a surface-launched drilling rig.
An environmentally beneficial technique, as compared to traditional cut and cover pipeline/utility installations, this method is routinely used when conventional trenching or excavating is not practical or when a minimal surface disturbance is required.
HDD can be utilised to cross any number of surface obstacles including roadways, railroads, wetlands, and water bodies of varying sizes/depths. Learn more about this process under The Rolkon Way
Ground Penetrating Radar
Ground Penetrating Radar (GPR) is used across a range of substrates from rock to soil. Using radar pulses to image the subsurface, GPR helps the team detect often-unmapped underground utilities that can cause endless delays and additional construction costs and civil projects if not identified.
This technology and Rolkon’s skill set are applied to carry out the key trenchless services of Horizontal Directional Drilling and Moling /Grundomat Soil Displacement.
Pipe Cracking / Bursting
Pipe cracking is a very effective trenchless service that is used to replace underground water and sewer pipes.
Instead of digging up the old or damaged pipes, this trenchless method makes use of a “bursting head” that is pushed into and through the existing pipe. This head fractures the old pipe and sends the remaining materials and fragments into the surrounding soil area. The new pipe is immediately pulled into place, with no extra step for pipe installation and no need to drill a new bore.
A service that Rolkon has always offered, it has not been a main focus of the business….until now that is!
With 197 000km of reticulation system in South Africa, the majority of which was built 30-60 years ago, ageing infrastructure and its impact on service delivery and new development is a major issue.
It is estimated that our losses on all these systems sit at about 37%, with the majority of this loss experienced in urban and peri-urban areas where trenching is difficult to implement. This of course makes it the perfect environment for trenchless services such as pipe cracking in that disruption is kept to a minimum and the safety of pedestrians is a key benefit.
Along the same vein, stormwater systems face the same ageing issue having exceeded their design life and subsequently collapsing. These need to be re-sleeved or made larger or completely replaced. Again the right environment for trenchless construction.
Environmental protection is another area of demand, where less invasive alternatives to trenching are becoming a baseline requirement of many construction and civil engineering projects.
With these pressing needs, Rolkon has expanded its offering in this space through investment in new machines, staff resources, skills development, and coverage that allows it to undertake mega pipe cracking projects.
The key advantages of pipe cracking are:
- Being a trenchless method, there is no-dig and little rehabilitation
- It can be used to replace pipes of any material ie: plastic, clay asbestos and the replaced pipe can also be of any suitable material.
- It allows for re-sleeving with smaller pipes or those of the same diameter as the old pipe, and it can also be used to expand pipeline capacity by replacing existing pipes with larger ones.
- The limited disturbance of ground, structures, services and traffic
- High-speed efficiency over conventional excavation or trenching
- No bedding or backfill is required
- It is more cost-efficient than conventional construction
How Does Pipe Cracking Work?
Using dedicated equipment and experienced operators pipe cracking is a relatively simple process:
- The rod of the pipe-bursting system is pushed into the existing pipe.
- Bursting blades are attached to the end of the rod and an expander is added which can be as much as 30% larger than the new pipe’s outside diameter.
- The new pipe is connected to the expander.
- The rod is pulled back through the pipe, drawing the bursting blades through the old pipe, breaking it up.
- The expander follows the bursting blades and is immediately pulled through the old pipe, expanding the burst pipe and pushing the fragments into the surrounding earth.
- The new pipe is attached to the expander and is pulled through the length of the existing bore.
When the bursting blades and expander leave the bore, the new pipe is in place, waiting to be connected to the appropriate service.
Grundomat Soil Displacement / Moling
In Moling or Grundomat Soil Displacement, pneumatically-driven hammers work according to the soil displacement method, when moving forward the spoil is displaced into the surrounding soil. A channel is produced into which socketless short or long pipes up to OD 160 made of plastic (LDPE) or cables can be pulled in.
Depending on the type of soil, pipe lengths of up to 25m can either be pulled in simultaneously or later. A compressor with 6 – 7 bar operating pressure is required for this, with the exact alignment of the machine towards the target necessary for high on-target accuracy.
What Is Trenchless Construction?
Trenchless construction is the technique by which a pipe, duct or cable can be installed underground without disturbing service structures such as roads, pavements and driveways, thereby avoiding the disruption caused by traditional open trenching methods.
Using Directional Drilling or Horizontal Directional Drilling (HDD) techniques, this unique offering provides a much-needed non-invasive tunnelling service for underground pipelines for sewer and water; fibre optic installation, and electrical sleeving. This to industries such as developers/consulting engineers/contractors/municipalities and parastatals.