scope:

1.1 This European Standard establishes general principles forthe execution of bored piles (see 3.2). NOTE 1 This standard coverspiles or barrettes which are formed in the ground by excavation andare structural members used to transfer actions and/or limitdeformations. NOTE 2 This standard covers piles with circularcross-section (see Figures 1 and A.1a)) and barrettes (see 3.3)with rectangular, T or L or any other similar cross-section (seeFigure 2) concreted in a single operation. NOTE 3 In the standardthe term pile is used for circular cross-section structure and theterm barrette for other shapes. Both are bored piles. 1.2 ThisEuropean Standard applies to bored piles (see Figure 3) with: ?uniform cross-section (straight shaft); ? telescopically changingshaft dimensions; ? excavated base enlargements; or ? excavatedshaft enlargements. NOTE The shape of a pile base and of anenlargement depends on the tool used for the excavation. 1.3 ThisEuropean Standard applies (see Note) to: ? bored piles with a depthto width ratio ? 5; ? piles (see Figures 1 and 3) with a shaftdiameter 0,3 m ? D ? 3,0 m; ? barrettes (see Figure 2) with theleast dimension Wi ? 0,4 m, a ratio Li / Wi between its largest andits least dimensions ? 6 and a cross-sectional area A ? 15 m?; ?piles with circular precast elements used as structural member (seeFigure 7) with a least dimension DP ? 0,3 m; ? barrettes withrectangular precast elements used as structural member with a leastdimension WP ? 0,3 m. NOTE The standard covers a large range ofdiameters. For small diameter bored piles less than 450 mm, thegeneral specification can be adapted to cater for the lack of space(e.g. minimum bars number and spacing). 1.4 This European Standardapplies to piles with the following rake (see Figure 4): ? n ? 4 (?? 76?); ? n ? 3 (? ? 72?) for permanently cased piles. 1.5 ThisEuropean Standard applies to bored piles with the followingdimensions of the shaft or base enlargements (see Figure 3): a)base enlargements: 1) in non-cohesive ground: DB / D ? 2; 2) incohesive ground: DB / D ? 3; b) shaft enlargements in any ground:DE / D ? 2; c) slope of the enlargement in non-cohesive ground m ?3; 1) in non-cohesive ground: m ? 3; 2) in cohesive ground: m ?1,5; d) base enlargements area of barrettes: A ? 15 m?; 1.6 Theprovisions of this European Standard apply to: ? single boredpiles; ? bored pile groups (see Figure 5); ? walls formed by piles(see Figure 6). 1.7 The bored piles which are the subject of thisEuropean Standard can be excavated by continuous or discontinuousmethods using support methods for stabilizing the excavation wallswhere required. 1.8 This European Standard applies only toconstruction methods that allow the designed cross-sections to beproduced. 1.9 The provisions apply to bored piles (see Figure 7)constructed of: ? unreinforced (plain) concrete; ? reinforcedconcrete; ? concrete reinforced by means of special reinforcementsuch as steel tubes, steel sections or steel fibres; ? precastconcrete (including prestressed concrete) elements or steel tubeswhere the annular gap between the element or tube and the ground isfilled by concrete, cement or cement-bentonite grout. 1.10Micropiles, mixed-in-place columns, columns constructed by jetgrouting, ground improvement for piling, mixed-in-place pile basesand diaphragm walls are not covered by this European Standard.