03-01-2013, 03:03 PM
METHOD STATEMENT for INSTALLATION OF MICROPILE
1METHOD STATEMENT.pdf (Size: 761.77 KB / Downloads: 1,253)
Grout
Grout shall be mixed from Ordinary Portland Cement and clean water free from harmful
substances. Usage of other cement which has a higher strength and/or workability shall
also be allowed.
Grout Test
Two sets of three test cubes shall be taken per one grouting operation for testing purpose.
Three test cubes shall be tested at 7 days and the remaining cubes at 28 days after casting.
The characteristic strength of the grout shall be 21 N/mm2 and 30 N/mm2 at 7 days and
28 days. (Note that expansion admixtures may cause a slight decrease in cube strength)
Main Load Bearing Component – Reinforcing Steel
The main steel component and the grout shaft of the micropile shall be designed to
support the external loads and bending to be transmitted to/from the load bearing stratum
for end-bearing/tension piles, which shall consist of a top anchorage or pilecap (provided
by the structural/pilecap contractor) and an axial steel component.
Typical axial steel component consisting of hot rolled deformed high tensile bar with
minimum yield stress of 460 N/mm2 or API Pipe.
Reinforcement Bars
1. The reinforcement of the piles are typically prefabricated on-site or elsewhere
and brought to site. The bars and links are tied together with tie wire to form
prefabricated cages.
2. To join the lengths of the cages, the reinforcement bars shall be lapped 40 times
the diameter or 40D. The joining of the bars (if necessary) shall be done by tie
wire or welding.
3. Spacers used shall be PVC pipes cut into small lengths and tied to the
reinforcement bars. Alternatively, ready-made PVC round spacers can be clipped
to the links. A second alternative consist of PVC lantern which is clipped to the
main-bars.