First vertical drilling successfully completed using the dry drilling method.
After many years of successful execution of the roadway development at Kazchrome in Chromtau (Kazakhstan), the team of TOO SCHACHTBAU KASACHSTAN has reached a new milestone - the first raise drilling with a diameter of 1.8 m and a depth of 52.2 m has been successfully completed
On 9 March at around 2:20 a.m. local time, the pilot bore was successfully widened as part of the project to excavate the weather heave of the explosives store on the -480 DNK shaft level. This step confirms the completion of the drilling phase in full compliance with the approved project. The raise boring was carried out in two phases using the Wirth HG-160/2 drilling rig: Pilot Hole (D=250.8 mm) and Raise Hole of the Pilot Hole (D=1829 mm). Due to the difficult geological conditions and the negative effects of water inflow on the stability of the rock, a dry drilling method without flushing fluid (i.e. compressed air flushing) was used. This success underlines the effectiveness of the chosen technology and the expertise of the team.
The team is currently preparing for the responsible task of securing the shaft. For this purpose, a centrifugal shotcrete system is used to apply the fibre-reinforced shotcrete, which enables the concrete to be applied radially and evenly to the joint in a 360° radius.
It should be emphasised that this type of work has not yet been carried out in Kazakhstan. We are currently in the final phase of testing the shotcrete equipment on a pre-installed model setup in order to simulate the upcoming shaft stabilisation work. The next step will be to transfer the experience gained to real underground conditions.
Glück Auf
Wirth HG160/2 drilling rig in the drilling chamber
Completion of the drill hole - the expander head is at the top
Overview of the breakthrough from above
Shotcrete system - condition on delivery
Adaptation of the system in the course of the test trials
Simulation on the model structure
Successful test trial