Lift blocks use sand for blocks bedding tamp down bedding about 1/2 " lower than level blocks then lay more sand in to just above the blocks base lay in the blocks board over top and tamp down with sledge hammer evenly over blocks a vibrater plate is expensive to hire.
Leave time in the day to do the job in one hit if you leave the open area over night the other set rows will move and you wont get your last few blocks back.
If you have to leave it then shutter the gap to stop the remaining blocks moving and put in cross bracers across to brace the shuttering. Don't peg the shuttering it won't work as effective as bracers.
I've done this on modular paving on excavations for GPO/BT To lift the existing sunken area you might have to drill in to one block deep enough to allow a rawplug pushed in just below surfaceand screw in large eyelet and attach rope to lift block tapping around blocks with rubber malet to help vibrate block free,.... been there done that.. Drill out rawl plug using twist bit for steel not masonary bit then fill hole in block after with cement or buy matching block.
bob, February 2011
