SATURATION, DEGREE OF (S.)The ratio,
expressed as a percentage, of the volume of water
in a given soil mass to the total volume of
intergranular space (voids).
SCALEThe ratio between the dimensions of the
graphic representation of an object and the
corresponding dimensions of the object itself.
SCALENE TRIANGLEA triangle in which no
sides or angles are equal.
SECANTThe ratio between the hypotenuse and
the side adjacent an angle in a right triangle:
sec = hyp/ad.
SECONDARY AUXILIARY VIEWAn auxil-
iary view that is used when neither the normal
views nor the primary auxiliary view shows the
features of an object in its true size and shape.
SECTION LINESThin diagonal lines used to
indicate the surface of an imaginary cut in an
SECTION VIEWA view used to show the
internal structure of an object; used when hidden
lines in the normal orthographic views do not
amply describe the object.
SECTOR OF A CIRCLEThe part of a circle
bounded by two radii and their intercepted arc.
SEGMENT OF A CIRCLEThe part of a circle
bounded by a chord and its arc.
SHRINKAGE LIMITThe maximum water
content at which a reduction in water content will
not cause a decrease in volume of the soil mass.
SHRINKAGE RATIO-The ratio between a
given volume change, expressed as a percentage
of the dry volume, and the corresponding change
in water content above the shrinkage limit,
expressed as a percent of the weight of the
SINEThe ratio between the side opposite
an angle and the hypotenuse of a triangle:
sin = opp/hy.
SKETCHA quick freehand drawing, usually
pictorial, used to convey information or an idea.
SOILA mixture of uncemented or loosely
cemented mineral grains enclosing various sizes
of voids containing air (or other gases), water, and
organic matter, or varying combinations of these
SOIL, COARSE-GRAINED-Soil in which more
than half of the material, by weight, is retained
on a No. 200 sieve.
SOIL, FINE-GRAINEDSoil in which more
than half of the material, by weight, passes a No.
SPACE BLOCKSStrips placed under the edges
of triangles, french curves, and like instruments
to prevent ink from running under the edge.
SPECIFIC GRAVITY, APPARENT (G~) The
ratio of the weight in air of a given volume of the
impermeable portion of soil particles to the weight
in air of an equal volume of distilled water, both
at a stated temperature.
SPECIFIC GRAVITY, BULK (G~) The ratio
of the weight in air of a given volume of
permeable material (including permeable and
impermeable voids) to the weight of an equal
volume of distilled water at a stated temperature.
SPECIFIC GRAVITY OF SOLIDS (GS) The
ratio of the weight in air of a given volume of soil
particles to the weight of an equal volume of
distilled water, both at a stated temperature.
SPHEREA solid figure having every point on
its surface equidistant from its center.
SQUAREAn equilateral rectangle.
STATIONA definite point on the earths surface
whose location has been determined by surveying
methods. It maybe a point on a traverse over which
an instrument is set up or a length of 100 ft mea-
sured on a given line-broken, straight, or curved.
STATION POINTSee POINT OF SIGHT.
STITCH LINEDark medium line consisting of
very short dashes closely spaced; used to indicate
stitching or sewing lines on an article.
SUBBASEThe course in the asphalt pavement
structure immediately below the base course is
called the subbase course. If the subgrade soil is
of adequate quality, it may serve as the subbase.