When IHC resumed its tunnelling activities in 2016, one of the key research areas identified concerned the renovation or replacement of existing underground infrastructure. As well as considering newly built utilities for fresh water, drainage and sewerage, we also learnt that there are hundreds of kilometres of pipes below the surface that are more than 50 years old.
In the coming years, a significant section of these pipes will have to be upgraded for various reasons. This could be due to the pipes leaking or the fact that they have been displaced by natural ground settlement. In some cases, they need to be replaced with pipes that can deliver a higher capacity.
A smarter solution
The standard method for replacement is currently to dig up streets, extract the old pipe and replace it with a new one. Although this seems cost effective, it can cause significant economic damage due to roads being closed for a period of time making houses and shops inaccessible.
IHC was convinced that this could be done in a smarter and more sustainable manner, using trenchless technologies. As a result, a project was initiated to develop a (semi-) automatic system capable of removing an existing pipe and leaving a new one in its place.
The final concept consisted of a robotic pipe-eating and replacing system, that can work silently underground with minimal disturbance. Once designed, our vision needed to be put into a practical solution.
This stage was accomplished by partnering with our customer – Woerden-based Gebr. Van Leeuwen Boringen – which specialises in microtunnelling. Gebr. Van Leeuwen had previously been working on a similar idea, as the pipe-eating method is not an entirely new concept but it has never been put into practice on a large scale.
The solution we developed presents a number of features based on both new and existing technologies. One key innovation is the excavation method and the fact that the pipe can remain operational during the replacement process.
This is achieved by the presence of a temporary pipe that runs through the centre of the machine to connect the old and new pipe. For the pipe construction, the system relies on existing pipe-jacking technology, however the team are exploring new theories technologies in this area that could be developed in the future.
The concept has been presented to several potential customers and their reactions have been highly positive. While the potential of trenchless technologies is not yet fully recognised among planners of utility infrastructure, the city of Rotterdam is an exception, having recently changed its policy to ‘trenchless unless…’ instead of the other way around.
Our current aim is to continue the detailed engineering and find a pilot project where the machine can be tested under real-life conditions.