Hearn Street

Supply of labour, plant and materials to excavate and construct sprayed concrete enlargements within existing 2.85m ID tunnel. Two enlargements up to 6 metre diameter were formed one for launching of TBM.

Works involved constructing a 3m diameter sprayed concrete lined shaft 15m deep within and below an existing live substation in poor ground conditions.

Upon completion of the shaft Shotcrete then drove the TBM segment lined tunnel from one of the enlargements to the shaft.

Considerable challenges were overcome with the extremely restricted site logistics and constructing the works within a live substation environment.