The no-dig , or trenchless technologies , of which IATT – a no- profit association, promotes the awareness, experimentation and diffusion in Italy, allow the laying, maintenance and rehabilitation of networks minimizing or completely avoiding open trenches and, compared to the latter, have the evident advantage of reducing:
- movement of debris and consequent heavy vehicle traffic and pollution;
- change of course (for pedestrian and vehicles) and public transportations delay, traffic jams;
- occupation area of public soil for the work site
- acoustic emissions;
- dust lifting;
- deterioration of road surface;
- disruption of commercial, residential or leisure activities;
- accidents for both worker and citizen walking by the interested area
There are called “ low environmental impact “ technologies, thanks to the results of important studies that tested how their use, in the urbanized area, reduces social environmental costs by 80% , energy consumption by 56% and by 67% on-site accidents.
No dig technologies are also extremely attractive options for crossing roadways and other transportation corridors, rivers and waterways, or in areas where there are restriction restricted due to the existence of structures or vegetation, for the laying of large diameter pipelines if necessary also at high depth.
In general compared to trench excavations, the no dig technologies are more economical, equally reliable and less invasive in terms of social inconvenience and deterioration of road surfaces. Their convenience appears even more clear if, in a whole financial evaluation, social costs are taken into consideration.
Internationally trenchless technologies may be subdivided into five groups:
- SURVEY INVESTIGATION
- DIRECTIONAL HORIZONTAL DRILLING
- NON GUIDED HORIZONTAL DRILLING
- ASSOCIATED TECHNOLOGIES
- REHABILITATION AND EXPLOITATION OF EXISTING INFRASTRUCTURES
Each technology will be described in the chart flow.