1.1 This European Standard establishes general principles for the execution of bored piles (see 3.2). NOTE1 This standard covers piles or barrettes which are formed in the ground by excavation and are structural members used to transfer actions and/or limit deformations. NOTE2 This standard covers piles with circular cross-section (see Figures1 and A.1a)) and barrettes (see 3.3) with rectangular, T or L or any other similar cross-section (see Figure2) concreted in a single operation. NOTE3 In the standard the term pile is used for circular cross-section structure and the term barrette for other shapes. Both are bored piles. [Image removed.] [Image removed.] 1.2 This European Standard applies to bored piles (see Figure3) with: uniform cross-section (straight shaft); telescopically changing shaft dimensions; excavated base enlargements; or excavated shaft enlargements. NOTE The shape of a pile base and of an enlargement depends on the tool used for the excavation. [Image removed.] [Image removed.] 1.3 This European Standard applies (see Note) to: bored piles with a depth to width ratio≥5; piles (see Figures1 and 3) with a shaft diameter 0,3m≤ D ≤3,0m; barrettes (see Figure2) with the least dimension W i ≥0,4m, a ratio L i /W ibetween its largest and its least dimensions≤6 and a cross-sectional area A ≤15m 2; piles with circular precast elements used as structural member (see Figure7) with a least dimension D P ≥0,3m; barrettes with rectangular precast elements used as structural member with a least dimension W P≥0,3m. NOTE The standard covers a large range of diameters. For small diameter bored piles less than 450mm, the general specification can be adapted to cater for the lack of space (e.g. minimum bars number and spacing). 1.4 This European Standard applies to piles with the following rake (see Figure4): n≥4 ( Θ≥76°); n≥3 ( Θ≥72°) for permanently cased piles. 1.5 This European Standard applies to bored piles with the following dimensions of the shaft or base enlargements (see Figure3): base enlargements: in non-cohesive ground: D B/ D≤2; in cohesive ground: D B/ D≤3; shaft enlargements in any ground: D E/ D≤2; slope of the enlargement in non-cohesive ground m≥3; in non-cohesive ground: m≥3; in cohesive ground: m≥1,5; base enlargements area of barrettes: A≤15m 2; 1.6 The provisions of this European Standard apply to: single bored piles; bored pile groups (see Figure5); walls formed by piles (see Figure6). [Image removed.] [Image removed.] 1.7 The bored piles which are the subject of this European Standard can be excavated by continuous or discontinuous methods using support methods for stabilizing the excavation walls where required. 1.8 This European Standard applies only to construction methods that allow the designed cross-sections to be produced. 1.9 The provisions apply to bored piles (see Figure7) constructed of: unreinforced (plain) concrete; reinforced concrete; concrete reinforced by means of special reinforcement such as steel tubes, steel sections or steel fibres; precast concrete (including prestressed concrete) elements or steel tubes where the annular gap between the element or tube and the ground is filled by concrete, cement or cement-bentonite grout. [Image removed.] 1.10 Micropiles, mixed-in-place columns, columns constructed by jet grouting, ground improvement for piling, mixed-in-place pile bases and diaphragm walls are not covered by this European Standard.