3 Definitions

For the purposes of this standard, the following definitions apply:

3.1

anchorage

anchoring system for the sheet pile wall, for example anchor plates or anchor walls including the connecting rods (tie rods), screw anchors, ground and rock anchors, driven ground anchors, anchoring piles and anchors with grouted or expanded bodies

3.2

auxiliary structures

all structures necessary for the proper and safe execution of the sheet piling works

3.3

bracing

a system of walings and struts to support the structure

3.4

combined wall

retaining wall composed of primary and secondary elements. The primary elements can be steel tubes, beams, or box piles. The secondary elements are normally U or Z-shaped steel sheet piles. Figure 1 shows examples of combined walls

3.5

comparable experience

documented, or other clearly established information related to the ground and installation conditions, involving similar types of soil and rock and for which similar behaviour is expected. Information gained locally is considered to be particularly relevant

3.6

cushion

material, fitted into a recess in the driving cap, which smoothes the impact force of the falling hammer on the driving cap and on the head of the sheet pile (see figure 2)

3.7

de-clutching

disconnection of the interlock during sheet pile driving

3.8

de-clutching detector

instrument for determining whether or not the interlocks of adjacent sheet piles are fully engaged during driving

3.9

driving cap

device, placed on the top of the sheet pile which transmits the blow of the hammer evenly, thereby preventing damage of the sheet pile head (see figure 2)

3.10

driving

any method of installing the sheet piles to the required depth

3.11

driving method

method of driving such as panel driving, pitch and drive, staggered driving by means of impact, vibration pressing or by a combination of these

3.12

driving assistance

method to reduce the penetration resistance during driving, such as jetting or pre-augering

3.13

fish plate, splice plate

steel plate which joins two lengths of sheet pile together (see figure B.2)

3.14

guide frame

frame consisting of one or more stiff guide beams, normally of steel or wood, to position and maintain the alignment of sheet piles during pitching and driving

3.15

hammer

part of piling equipment for driving sheet piles by percussion impact

3.16

leader

beam or similar, attached to the driving rig to lead the sheet pile and the hammer (or the vibrator) during driving (see figures 2, 3 and 5 )

3.17

leader slide

guiding device connecting the drive cap and/or the hammer to the leader (see figures 2 and 3)

3.18

leading system

whole system to guide the sheet pile and the hammer (or the vibrator) during driving (see figure 3)

3.19

rock dowel

rod protruding from the toe of the sheet pile, used for fixing sheet piles to the bed-rock (see figure 13)

3.20

screw anchor

rod with a screw blade at the end, which is rotated into the natural ground behind the sheet piles to provide an anchorage

3.21

shackle

device for lifting sheet piles from the ground and placing them in the vertical position (see figure A.7)

3.22

sheet pile

individual element of a sheet pile wall (single, double or multiple sheet pile)

3.23

sheet pile wall

screen of sheet piles which forms a continuous wall. For steel sheet piles continuity is provided by interlocking of the joints, fitting of longitudinal grooves or by means of special connectors and for timber sheet piles, by tongue and groove

3.24

sheet pile wall structure

structure, consisting of sheet piles, soil and rock, anchorages, bracings and walings, which retains ground and water. The elements are shown in figure 4

3.25

site inspection

inspection of the construction site and its surroundings

3.26

site investigation

geotechnical investigations on and near the construction site

3.27

slippage

relative longitudinal displacement between the interlocks of adjacent sheet piles

3.28

strut

long compression member, usually of steel, wood or reinforced concrete, for the support of the sheet pile walls and normally connected to the walings

3.29

template

specific type of guide frame, used for positioning curved or angled sheet pile walls. They often incorporate a working platform or access staging for piling operatives

3.30

threader

device fixed to the toe of a sheet pile in order to guide the sheet pile into the interlock of a sheet pile already placed in the guide frame (see figure A.8)

3.31

vibrator

vibrating unit for the driving and extraction of the sheet piles and the primary and secondary elements of a combined wall

3.32

waling

horizontal beam, usually of steel or reinforced concrete, fixed to the sheet pile wall and connected to the anchorage or struts, in order to distribute the applied anchor– or strut forces equally over the sheet pile wall.