Trenchless Technology Advice

Do you need independent professional advice and design experience in selecting and specifying a trenchless technology solution? What are the benefits against costs?

Trenchless technology or “no dig” solutions are becoming more commonly used in the UK. They are, however still specialist techniques, requiring practical design and construction experience along with special construction equipment.

We are one of the few experienced Civil Engineering Consultants in the UK involved in the selection and specification of such trenchless technology techniques.

We provide practical consultant views for international Trenchless Technology magazines and other independent industry publications. See our article in the world leading international trenchless technology publication – Trenchless World Sept 2013 edition, for example.

Wilsham Trenchless World Sept 2013

There are a multitude of trenchless contractors, but far fewer consultants in the industry with hands on experience. The key is often to provide independent professional advice and integrate the proposals with the wider site issues, such as; drainage, foundations, groundwater, tree preservation orders and other services.

Our Trenchless Technology Design Service

Our bespoke service would typically include:

  • Advising a client of trenchless options, the pros, cons and approximate costs.
  • We specify the works.
  • We produce designs and competitively tender.
  • We integrate with the rest of the water/drainage design.
  • We review and advise on contractor selection.
  • We will meet the chosen specialist trenchless technology contractor and run through the proposed works, method statements, risks, safety, environmental and programming constraints.
  • We would usually go to site during the works to check all is acceptable.

Trenchless Techniques

We have experience of of designing and specifying all of the following trenchless techniques:

  • Directional drilling
  • Pipe-bursting
  • Auger boring
  • Pipe jacking
  • Slip-lining

No dig

“No dig” is not really an appropriate description as they practically always require some excavation. Such excavation can however be more limited than would have otherwise been the case. Usually a launch pit and reception pit will need to be dug.

There is an initial set up cost associated with the works which can be several £1000. However, generally they are far more cost effective than deep trenches, over long distances or where there are traffic, building, trees or services issues. The main benefit, more important than cost and time – is safety. Sending men in a deep construction trenches, even with full temporary support, is not idea or something we recommend. We believe a professional consultant has the responsibility to try and design out or minimise the risk, way before a contractor is chosen. By the greater use of trenchless solutions the design can be amended to reduce the need and time for contractors to be in trenches.

For the drilling/auger/jacking techniques obviously the type of ground to go through is critical to the correct selection.

Our trenchless technology experience

The techniques can be used in a multitude of situations. We have specified in the following circumstances:

  • Installation of a 200m long surface water drain by directional drilling under trees with a preservation order and a grade 2 listed house. The drain was installed at an average depth of 6m. Clearly traditional open cut would not have been viable.
  • Installation of a 450mm clean water trunk main under 8 lanes of the A4/M4 in London by directional drilling. Clearly excavation costs and disruption would have been considerable.
  • A 3km long 80mm pumped foul sewerage system, by directional drilling.
  • A 1.2m diameter strategic water main around a hill by pipejacking, including a 12m deep central shaft.
  • Pipe-busting small clean water mains in central London.

More advice can be found on the UKSTT (United Kingdom Society for Trenchless Technology) website. UKSTT is a registered charity involved in the development and promotion of Trenchless techniques, sometimes called ” No-Dig” techniques. We tend to avoid the term no-dig, as clearly you always need to dig something ( a launch and reception pit etc). What you are avoiding is the need for long deep trenches which could be expensive, destabilise foundations or other.