Pipe Specs:
160mm & 110mm HDPE
Max Length:
600m
Max Depth:
20m
Geology:
Alluvials, Rock
HDD Crossing:
Road
Pipe Application:
Electrical, Comms
Horizontal directional drilling was used to great success in this project to provide increased power and communications capabilities to Tweed Valley Hospital. With limited accessibility and a restrictive construction corridor, HDD’s small site footprint enabled the road crossings to be optimised for maxi-rig construction in an efficient, parallel design.
The narrow, curved easements available for the pipelines, along with the high concentration of existing and future planned services in the area, were key factors in the HDD design from the beginning. Originally conceived as several shorter crossings, by instead opting for longer, parallel crossings with curved alignments, the HDD crossings were able to be designed within the very tight easements while taking into account the variable rock and alluvial ground conditions.
The construction phase also presented some additional challenges. With the project location bordering a residential area, strict noise restrictions applied, and additional limitations to entry and exit pits and pipe stringing areas needed to be factored in. Large boulders identified close to surface added to the difficult conditions, but with a methodical, flexible, and client-focused approach, contractor UEA successfully completed the crossings in early 2022.