Trenchless connections combining Grundopit & Grundotugger

TT-UK were contacted by Nick Lewis of Oakland Partners, property developers, who are currently constructing a small development in Cromer Road, Finedon in Northants. The problem that Oakland Partners found themselves with was that they had to connect the new properties to the existing sewer line which is 4 metres deep under the existing highway. Also the second challenge to Oakland Partners was that they also had to connect the properties to the existing storm water outlet, a shorter distance but at a much steeper gradient.

Nick Lewis contacted TT-UK’s specialist drilling engineer, Jim Albarella, to ascertain whether we could assist in carrying out these highly difficult projects.

Following a site visit by TT-UK’s directional drilling specialists, it was agreed that the above works could be carried out on a paid demonstration basis using a Grundopit powerful mini steerable boring system com-bined with a Grundotugger to upsize the pilot bore holes. The 15 m pilot bore from the launch pit down to the existing sewer in the roadway some 4 m deep had to be accurately installed at a gradient of 11%.

The second bore to be carried out from the same launch pit was 7 metres in distance into the existing storm water drain. This also had to be accurately installed but with a steeper inclination of 14% and a depth of 3.35 metres.

Radio Detection’s ITrack system was used to maintain the correct gradient throughout the pilot boring operation.

Having carried out the pilot bore and subsequent pre reaming operation, the demonstration engineers then carried on with the upsizing operation using a Grundotugger and the 190mm pre-reamed bore was upsized to 220mm in diameter to accommodate the new 180mm SDR11 PE pipe which was supplied in 750mm sections with screw type joints. Short length PE pipes were used so they could be lowered down and connected through the 900mm diameter manhole entry

The Grundopit pilot bore, pre-reaming operation, and the Grundotugger upsizing operation on both bores was carried out and completed in 2 working days to the complete satisfaction of Oakland Partners.