

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.