11 Special requirements

11.1 Regarding:

  • a) safety on the site;
  • b) safety of the working practices;
  • c) operational safety of piling and auxiliary equipment and tools.

The respective national standards, specifications or statutory requirements for execution of micropiling works shall be observed, as long as respective European Standards are not available.

Equipment shall be in accordance with EN 791 and EN 996.

11.2 Regarding nuisance and environmental protection, for each particular situation, as long as respective European Standards are not available, the national requirement and the local requirements shall be observed.

11.3 For all materials used during the execution of the micropiles, environmental suitability shall be proven by the contractor and agreed by the Client's Technical Representative, who acknowledges the use of the materials or additives.

11.4 Impact adjacent structures and slopes

11.4.1 When specified in the project documentation the condition of adjacent structures and slopes shall be carefully observed and documented prior and during the execution of the micropile works.

11.4.2 When specified in the project documentation, surrounding structures and slopes shall be adequately monitored by repeated levelling and alarm systems shall be employed where appropriate.

Examples of micropile shafts and bases
Figure 1 — Examples of micropile shafts and bases
Definition of rake
Figure 2 — Definition of rake
Examples of micropile structures

Key

  • 1 Single micopile
  • 2 Micropile groups
  • 3 Reticulated micropiles
  • 4 Micropile walls
Figure 3 — Examples of micropile structures
Examples of base and shaft enlargements

Key

  • 1 Drilled micropile with base enlargement
  • 2 Cast-in-place cased micropile with base enlargement
  • 3 Micropile with base of expanded body
  • 4 Micropile with enlargement by grouting
Figure 4 — Examples of base and shaft enlargements
Definition of overlength

Key

  • 1 Overlength
  • 2 Cut-off level
  • 3 Reinforcement
Figure 5 — Definition of overlength
Filling up a borehole with grout
Figure 6 a) – Filling up a borehole with grout
Single step grouting through a temporary casing
Figure 6 b) – Single step grouting through a temporary casing
Single step grouting through a load bearing element
Figure 6 c) — Single step grouting through a load bearing element
Single step grouting through a tube-à-manchettes

Key

  • 1 Packer
Figure 6 d) — Single step grouting through a tube-à-manchettes
Multiple step grouting through a tube-à-manchettes or special valves

Key

  • 1 Packer
Figure 6 e) — Multiple step grouting through a tube-à-manchettes or special valves
Single step grouting through several post-grouting tubes
Figure 6 f) – Single step grouting through several post-grouting tubes
Figure 6 — Examples of grouting methods

EN 14199:2005 Execution of special geotechnical works — Micropiles