Scope of Works
The proposed sewer pipe was a gravity main that connected into existing services and was required to be installed at 0.5% grade. The major issue on the project was the inconsistency of the ground conditions – bore 1 was in hard displaceable clay, bore 2 was in hard shale, and bores 3 and 4 were in hard rock.
UEA used a combination of a guided boring machine and a laser guided rock case boring machine to complete the required on-grade pilot bores. The GBM provided a suitable level of accuracy in the mixed ground conditions at +/- 25mm accuracy. A conventional auger boring machine was then used to install the 450mm steel casing, inside of which the carrier pipes were installed and grouted.
All works were completed on time and within required tolerances.