Pipe Jacking &
Trenchless Construction Services
Precision underground pipe installation without the disruption of open trenching. Delcon drives reinforced concrete pipe beneath roads, railways, and waterways across South Africa on grade, on programme, and with minimal surface impact.
Technical Specifications
- Pipe diameters: 900mm – 2800mm
- Reinforced concrete pipe (RCP) jacking
- Culvert & box culvert jacking
- Laser-guided bore alignment
- Launch and reception shaft construction
- Annular void grouting
- Inter-jack stations on long drives
- National coverage South Africa
The Problem with Open Excavation
Traditional open-cut excavation has a fixed and often underestimated true cost: long trenches through live roads, weeks of reinstatement, traffic management schemes, utility service diversions, and the compounding delays that follow. On any crossing where the ground above must remain intact a national route, a rail line, an active drainage channel open trenching is rarely the right answer.
Pipe jacking eliminates the trench entirely. Using hydraulic jacks at a pre-constructed launch shaft, Delcon pushes reinforced concrete pipe through the ground in a controlled, steerable bore reaching a reception shaft on the far side with the surface above undisturbed. It is the established trenchless construction method of choice for large-diameter gravity sewer, stormwater, and culvert crossings across South Africa.
How a Pipe Jacking Drive Works
Every pipe jacking project follows a structured sequence engineered for accuracy, safety, and programme certainty from first mobilisation through to hydraulic handover.
Ground Investigation & Drive Design
Targeted geotechnical boreholes characterise the soil profile, groundwater conditions, and any obstructions along the bore alignment. The bore profile, shaft locations, jacking load estimates, and lubrication strategy are all resolved on paper before any machine mobilises to site.
Launch & Reception Shaft Construction
Shafts are excavated and lined using sheet piling, precast concrete rings, or in-situ reinforced concrete, depending on depth and ground conditions. The jacking frame, thrust wall, and guide rails are installed and surveyed into the launch shaft before boring begins.
Boring & Pipe Jacking
A steerable cutting head is advanced by the hydraulic jacking frame. RCP sections are added progressively in the launch shaft as the bore advances. A laser guidance system monitors line and level throughout the drive, maintaining grade within ±10mm of design alignment.
Lubrication & Jacking Load Management
Bentonite slurry is injected at the cutting head and through intermediate ports in the pipe string to reduce skin friction on longer drives. Jacking loads are monitored continuously, and inter-jack stations are deployed when required to manage force across extended pipe strings.
Grouting, Testing & Handover
Once the bore reaches the reception shaft, the annular void behind the pipe is pressure-grouted to prevent ground settlement. Shafts are connected to the pipeline, the bore is cleaned out, and full hydraulic testing is completed before as-built survey and formal client handover.
Why Clients Specify Trenchless
Zero Surface Disruption
Roads, pavements, rail lines, and landscaping above the alignment remain intact. Only two compact access shafts are required one at the drive start, one at the end.
Compressed Programme
Eliminating the reinstatement cycle excavate, lay pipe, compact backfill in lifts, resurface dramatically reduces time on site, particularly on live road and railway crossings where every day of disruption carries a cost.
High-Precision Grade Control
Laser guidance maintains bore alignment and invert level within ±10mm of design making pipe jacking the correct method wherever gravity sewer hydraulic gradients are critical and cannot be approximated.
Reduced Risk to Existing Services
A steerable bore head navigates between buried utilities with accuracy. Compared to open excavation, the risk of striking live gas, water, or electrical services is substantially lower.
Minimal Environmental Footprint
Less spoil, lower noise, no damage to tree root systems, and no long corridor of disturbed ground. Underground pipe installation using trenchless methods is the preferred approach in sensitive environmental zones, riparian areas, and flood plains.
Long-Term Asset Performance
Jacked reinforced concrete pipe benefits from controlled jointing conditions, consistent ground support, and the structural arch effect of the undisturbed surrounding soil all factors that contribute to a longer operational service life than open-cut equivalents.
What Delcon Delivers
Typical Applications
Pipe jacking is specified wherever surface access is restricted, the structure above must be protected, or the programme demands a faster and lower-impact alternative to conventional excavation.
- Stormwater and sewer crossings under national roads and provincial routes
- Culvert jacking under active railway embankments
- Water supply pipeline crossings beneath rivers and flood channels
- Utility duct installation under airport taxiways
- Multi-cell culvert jacking for high-flow stormwater relief
- Gravity sewer mains under developed urban areas where open trenching is not viable
- Pipeline crossings through conservation areas and wildlife corridors
- Infrastructure connections to new developments in constrained environments
Pipe Jacking vs. HDD
Both pipe jacking and horizontal directional drilling (HDD) are trenchless methods, but they suit fundamentally different applications. Specifying the wrong one adds cost and risk to a project. Delcon provides a formal method selection recommendation on every project before procurement is finalised.
| Factor | Pipe Jacking | HDD |
|---|---|---|
| Typical diameter | 900mm – 2800mm | 100mm – 900mm |
| Pipe material | Reinforced concrete, steel, GRP | HDPE, steel, fusible PVC |
| Grade control | ±10mm high precision | Approximate (curved bore path) |
| Gravity sewer | Ideal method | Not suitable |
| Ground conditions | Wide range, including rock with correct tooling | Soft to medium soil; rock-free preferred |
| Drive length | 10m – 500m per individual drive | Up to 1500m continuous |
| Settlement risk | Low (controlled face pressure) | Moderate (annular grouting required) |
| Unit cost tendency | Competitive at large diameter | Lower at small diameter / long runs |
Delcon covers both methods. Where HDD is the right tool typically HDPE or steel pressure mains from 100mm to 900mm our team delivers that too. One contractor, full trenchless capability.
Related Services
Ready to Eliminate the Trench?
Whether you're scoping a road crossing, a railway culvert, or a gravity sewer main, Delcon's team is ready to assess your site and put real numbers to your project.