Grout Pumping and Injection Operations TR 003 ▪ Monitor grout pressure. ▪ Adjust grout flow and rate of pressure increase using the flow regulation valve. ▪ When grouting finished, turn flow control valve back to zero (clockwise) and turn grout pump lever to OFF position (horizontal). 3.2. Injecting the Grout The following instructions detail the correct methods for the injection of grout: ▪ Pump grout through the delivery hose until neat grout appears and the flow is constant. This means that any oil or water in the line is cleared and that only grout flows continuously from the hose. ▪ Attach the grout delivery hose to the packer and open the packer valve, if not already open. The grouting hole pattern is typically grouted in a sequence from the bottom to the top of the face. ▪ Commence pumping the grout slowly into the hole. ▪ Pump the grout according to the relevant approved grouting flowchart or instruction for the specific area of the mine. ▪ Monitor and record the grout pressure, grout volume and grouting time on the recording sheet at between 5 and 10 minute intervals. ▪ Always mix and transfer the grout to the agitator tank to ensure continuous pumping. ▪ Continually monitor face conditions and the surrounding area for any grouting related disturbance or leakage. If grout leakage occurs from the rock, slow down pump or adjust batches to a lower water binder ratio. Stop if necessary and use timber wedges, rags, discarded cement bags etc to stem the grout leaks and ensure grouting pressure is maintained. The method deemed to be most successful will depend on ground conditions. ▪ If grout flows from an adjacent hole that has not been grouted it must be monitored. Once pure grout flows, the packer valve on the leaking hole must be closed and all connected holes shall be grouted on rotation until each hole achieves stop pressure. If new cracks begin to open up in the fibrecrete or rock mass, especially behind the injection area, immediately stop operations, barricade the area and notify your supervisor. Opening up of cracks may indicate imminent ground failure.
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