Question $6[5$ Marks$]$

Fill in the missing words:

$6\mathrm{.}1$ The natural slope, known as the angle of repose, of soil is measured in relation to the vertical and ranges from $37$ for dry sand and gravel to almost $0$ for

$1$

$6\mathrm{.}2$ Name the square timbers used to support the walings in excavation timbering.

$1$

$6\mathrm{.}3$ refers to the topmost part of the embankment of the dam. It is sometimes used as a road.

$6\mathrm{.}4$ Machines like bulldozers and angledozers are primarily high$-$powered tractors on $($instead of tyres$)$ to reduce the risk of punctures and provide more traction when moving large amounts of soil.

$1$

$6\mathrm{.}5$ A is a watertight enclosure used to enable excavation in waterlogged sites or water bodies by preventing water from entering the area, and it is constructed using interlocking steel sheet piles.

$1$