Barrow Reservoir No. 3
Barrow No. 3 reservoir has a long history of leakage and remedial works. The 12m high embankment dam, constructed in 1863, is owned by Bristol Water plc and is one of three reservoirs known locally as “The Tanks”. In the summer of 2012 a phase of remedial works was required to stabilise the embankment of Barrow Reservoir Number 3.
Soil Engineering were appointed by Bristol Water to carry out stabilisation works using Tube-a-Manchette (TAM) techniques, injecting grout into the dam structure and underlying rock
Soil Engineering installed 452 TAMs at 1.5m intervals along the crest of the embankment to a maximum of 18m depth. This was achieved using 3 rigs to install the total of 6875m of TAM pipe required. .
Grouting of the embankment took over approximately 35,000 injections of cement-bentonite grout. This was completed over a period of some 26 weeks, an included a total injected grout volume of 1,101,404 litres.
Phase Two, comprised the construction of a 1.3m thick, 1.4km long slurry wall along the crest of the dam. Soil Engineering appointed Bachy Soletanche’s Specialist Geotechnics division as a specialist contractor to carry out this work.
A catch trench was excavated along the outer edge of the embankment crest to intercept drilling fluids and any surfacing grout. This prevented damage to an adjacent SSSI, and provided for a cleaner and safer working environment.