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V1.4 March 15
7.5 Grouting Methods
7.5.1 Pre-grouting with external grout pipe
The following steps should be carried out when pre-grouting the borehole:-
1.) Flush out the borehole with clean water and check the depth.
2.) Lower the grout pipe to the bottom of the borehole.
3.) Pump in the grout to fill the borehole then and remove and flush out the grout pipe.
4.) Attach the relevant bottom cap to the first length of inclinometer Casing.
5.) Install the Casing into the borehole to the specified depth, ensuring that the Casing is
filled with water to counteract any buoyancy and grout pressure.
6.) Lower a steel bar or drill rods to the bottom of the Casing to further counteract buoyancy
if necessary.
7.) Allow the grout to set.
8.) If necessary add grout to the top of the borehole and fit a protective cover.
IF THE ALIGNMENT OF THE CASING NEEDS CHANGING LIFT THE
CASING UP AND DOWN IN THE GROUT WHILST TURNING. DO NOT
JUST TWIST AS THIS WLL CAUSE TWISTING OF THE CASING
Grout pump
& mixer
Tremie pipe
Bentonite
cement
grout
QJ Casing
Casing clamp
Top cap
Protective
cover
