Techniques and Hardware Used
Phase 1 works were carried out whilst the station was closed and detailed core logs drawn up for the design team detailing the depth, type of material drilled etc.
Phase 2 works were carried out with the station in full operational mode. Several techniques were explored including stitch drilling from ground level down to the required depth, plunge wiresawing from ground floor level. Through the use of 3D modelling each technique was explored and the pros and cons assessed.
The technique that fitted best with the client’s and H&S requirements was to wiresaw the wall in sections to the required line from the base of the wall and then peeling the cut section away using a brokk. The wall foundation was then drilled and burst.