scope:

1.1 This European Standard establishes general principles forthe execution of micropiles. They are for drilled piles constructedusing a drilling tool with a diameter less than 300 mm. NOTE 1 ThisEuropean Standard is not applicable to driven piles, the executionof which is governed by EN 12699. NOTE 2 For a definition of shaftdiameter see 3.3. 1.2 Micropiles are structural members to transferactions to the ground and can contain bearing elements to transferdirectly or indirectly loads and or to limit deformations. Forexamples of micropiles see Figure 1, Figure 2 and Figure 3. Theirshaft and base resistance can be improved (mostly by grouting) andthey can be constructed with (see Figure 4): ? uniform crosssection (straight shaft); or ? telescopically changing shaftdimensions; ? shaft enlargements; and/or ? base enlargement. 1.3Other than practical considerations, there are no limitationsregarding, length, inclination (definition of inclination, seeFigure 5), slenderness ratio or shaft and base enlargements. 1.4The provisions of this European Standard apply to (see Figure 6): ?single micropiles; ? micropile groups; ? reticulated micropiles; ?micropile walls. 1.5 The material of micropiles covered by thisEuropean Standard can be: ? steel or other reinforcement materials;? grout, mortar or concrete; ? a combination of above. 1.6Micropiles can be used for: ? working under restricted accessand/or headroom conditions; ? foundations of new structures(particularly in very heterogeneous soil or rock formations); ?reinforcing or strengthening of existing structures to increase thecapacity to transfer load to depth with acceptable load settlementcharacteristics, e.g. underpinning works; ? reducing settlementsand/or displacements; ? forming a retaining wall; EN 14199:2015 (E)6 ? reinforcing of soil to form a bearing and/or retainingstructure; ? improving slope stability; ? securing against uplift;? other applications where micropile techniques are appropriate.1.7 Deep mixing columns according to EN 14679 are not included inthis European Standard. Columns constructed by jet grouting arecovered by EN 12716. Ground anchors are covered by EN 1537.