Question

What is main principle of post-grouting for mini-piles?

Answer

During course of post-grouting, a tube with a hole at its base is lowered into pile and grout is injected. Device of post-grouting is as follows- pressurized grout is at first confined by hardened grout and is able to hardly get away. Then, it ruptures grout cover and makes its way to surrounding soils and into soft regions to expand an interlock with harder soil zones. In order to improve pressurized grout to rupture initial grout depth, an utmost time limit is usually imposed between time of initial grouting and time of post-grouting to keep away from development of high strength of initial grout.
So, effect of soil disturbance by putting in of casings and subsequent lifting up of casings will be lessened appreciably.