3 Terms, definitions and symbols

3.1 Terms and definitions

For the purposes of this document, the following terms and definitions apply.


bearing plate

fr: plaque d’appui

de: Kopfplatte

plate connected to the head of the soil nail to transfer a component of load from the facing or directly from the ground surface to the soil nail


design life

fr: durée de service

de: Entwurfslebensdauer

service life in years required by the design


drainage system

fr: système de drainage

de: Dränagesystem

series of drains, drainage layers or other means to control surface and ground water



fr: parement

de: Frontausbildung

covering to the exposed face of the reinforced ground that may provide a stabilising function to retain the ground between soil nails, provide erosion protection and have an aesthetic function


facing drainage

fr: drainage de parement

de: Dränage der Frontausbildung

system of drains used to control water behind the facing


facing system

fr: système de parement

de: Frontausbildungssystem

assemblage of facing units used to produce a finished facing of reinforced ground


facing unit

fr: élément de parement

de: Frontausbildungselement

discrete element used to construct the facing


flexible facing

fr: parement flexible

de: bedingt nachgiebige Frontausbildung

flexible covering which assists in containing soil between the nails



fr: terrain

de: Baugrund

soil, rock and fill existing in place prior to the execution of the construction works


hard facing

fr: parement rigide

de: starre Frontausbildung

stiff covering, for example sprayed concrete, precast concrete section or cast in-situ concrete


production nail

fr: clou de l’ouvrage

de: Bauwerksnagel

soil nail which forms part of the completed soil nail structure


reinforcing element

fr: élément de renforcement

de: Bewehrungselement

generic term for reinforcing inclusions inserted into ground


reinforced ground

fr: massif renforcé, sol cloué

de: bewehrter Boden

ground that is reinforced by the insertion of reinforcing elements


sacrificial nail

fr: clou sacrificial

de: Sondernagel

soil nail installed in the same way as the production nails, solely to establish the pullout capacity but not forming part of the soil nail structure


soft facing

fr: parement souple

de: vollkommen nachgiebige Frontausbildung

soft facing has only a short-term function to provide topsoil stability while vegetation becomes established


soil nail

fr: clou

de: Bodennagel

reinforcing element installed into the ground, usually at a sub-horizontal angle, that mobilises resistance with the soil along its entire length


soil nail construction

fr: ouvrage en sol cloué

de: Vernagelungsbauwerk

work that incorporates soil nails, and can have a facing and/or a drainage system


soil nail system

fr: système de clouage de sol

de: Bodennagelsystem

reinforcing element which may include joints and couplings, centralisers, spacers, grouts and corrosion protection


test nail

fr: clou d’essai

de: Prüfnagel

nail installed by the same method as the production nails for the purpose of verifying the pullout capacity and durability, and could be forming a part of the structure


proof load

fr: chargement d’essai

de: Prüflast

load applied in the testing

3.2 Symbols

3.2.1 Agt elongation of a metallic reinforcement.

3.2.2 fy yield strength of steel.

3.2.3 Ldb debonded nail length.

3.2.4 pp proof load (maximum load to which the nail is subjected during the test).

3.2.5 P0 datum load.

3.2.6 Rt load at which pullout failure occurs.

3.2.7 Rt,k characteristic value of the structural tensile resistance of the test soil nail or any of the extension pieces.

3.2.8 Rt0.1,k characteristic value of the 0,1 % yield resistance of the test soil nail or any of the extension pieces.

3.2.9 s1, s2 measured nail displacement at time t1 and t2 respectively.

3.2.10 sr residual nail displacement.

3.2.11 s0 initial nail displacement.

3.2.12 t1, t2 measurements taken at time t1 and t2.

EN 14490:2010 Execution of special geotechnical works – Soil nailing