Processes (03 35xxx)

sudden major escape of compressed air (BS EN 12110) from a tunnel (01) or caisson (01), often accompanied by an inrush of soil (01) and water

reduce air pressure in a compressed air caisson (03 46024) to overcome resistance to sinking

temporary frame (01) or layers of horizontal members that transfer a vertical load (01) from one structural member (01) from one level to another

load (01) from one structural member (01) that may be applied to a pile (01), taking account of its ultimate bearing capacity (03 27036), negative skin friction (03 36008), pile (01) spacing, overall bearing capacity of the ground (01) below, allowable settlement (01) and appropriate factor of safety (01)

load (01) from one structural member (01) that a pile (01) is designed to carry

load (01) from one structural member (01) that a pile (01) carries in service

load (01) from one structural member (01) greater than the pile design load (03 36003) applied to a selected pile (01) to confirm its suitability

supportive adhesion (01) by which a pile (01) shaft transfers load (01) from one structural member (01) into surrounding soil (01) or fill (01)

support given by the combined effect of shaft friction (03 37003) and shaft adhesion (03 36006)

cf. skin friction (03 27019)

downdrag

downward pressure, exerted by a combination of frictional forces (01) and adhesion (01) on a pile (01) by surrounding soil (01) or fill (01), when the soil (01) or fill (01) settles relative to the pile (01) shaft

schedules (10 26009) of pressure changes with time, which govern the return to atmospheric pressure of persons subjected to a higher pressure

impact hammer (BS EN 12699) that uses internal power to raise the pile ram (03 36018) and is then allowed to fall

impact hammer (BS EN 12699) that uses internal power to raise the pile ram (03 36018) and to increase the downward force (01)

impact hammer (BS EN 12699) raised by a winch (12 36023) and allowed to fall

movable structure (01) for installing driven piles (BS EN 12699) with an impact hammer (BS EN 12699) in the correct position and alignment

cap placed temporarily on top of a steel pile (03 32017) to distribute the blow (03 34005) over the cross-section and to minimize damage to the pile head (BS EN 12699) during driving (BS EN 12699)

boring tool in the form of a cylindrical container, at the bottom of a kelly bar (03 36017) that incorporates cutting teeth or blades and has corresponding openings in its base plate (01)

sliding shaft on a drilling rig (12 26045) that transmits the driving force (01) or torque to the drill (12 16005) from a driven rotary table

rising and falling part of an impact hammer (BS EN 12699)

airtight platform (06 52012) in a caisson (01) or shaft (01) for compressed air work (03 34006)

decrease or increase in intensity of vertical loading at the base of a foundation (01) due to excavation (01) or the weight (11 27002) of a new structure (01) including earthworks (01)

cf. net loading intensity (03 27037)

mass (11 27001) of soil (01) around and beneath a pile (01) or group of piles (01) that is subjected to stress (01) by the applied loading

cf. bulb of pressure (03 27043)

supportive friction by which a pile (01) shaft transfers load (01) from one structural member (01) into surrounding soil (01) or fill (01)

stroke

distance which a drop hammer (03 36012) or pile ram (03 36018) falls

illness that may be suffered by people who are subjected to a too rapid reduction in air pressure after they have been doing compressed air work (03 34006)

bends

decompression illness (03 39001) caused by the formation of nitrogen bubbles in limb joints

decompression illness (03 39001) affecting cardiovascular,

neurological, respiratory or gastro-intestinal systems

6 Tunnels, shafts and caissons (03 4xxxx)