Microtunneling and horizontal drilling: French national project "microtunnels" guidelines

Trenchless technology allows the installation or renovation of pipelines by limiting the inconvenience caused to residents, particularly in urban areas. These innovative sites were introduced in France at the end of the 1980s. They include various techniques ranging from the installation of new networks by boring or horizontal drilling to the refurbishment or renovation of existing networks.
For almost 15 years these techniques have been widely developed in France, thereby contributing to the taking into consideration of environmental constraints in urban infrastructure projects. To this day, hundreds of kilometers of networks have been laid using these techniques.
But for all that, during the early years when these techniques were first introduced in France, there were difficulties and even setbacks which indicated the need to progress not only in terms of equipment but also in terms of research in order to refine the methods of calculation, bore fluids, work parameters and soil-machine interactions, etc.