HGE CE REF

convex (downward curve)

mercury in an open manometer forms a ____ meniscus

concave (upward curve)

water in an open manometer forms a ____ meniscus

surface tension

primary force that causes water droplets to assume a spherical shape

cohesion

helps hold molecules together

adhesion

refers to the attraction to other materials

viscocity

resistance to flow; affects droplet behavior when moving

RM

resisting moment to overturning

triaxial test

standard laboratory test for determining shear strength under controlled drainage/ consolidation conditions

direct shear test

common lab test where a soil sample is sheared along a predetermined plane

permeability test

both constant-head and falling head permeability tests are routinely performed in the lab

vane shear test

designed as an in situ field method (especially for soft clays) and isn’t a conventional lab procedure

Liquefaction

loss of shear strength in saturated soils during such earthquakes where cyclic or dynamic loading increases pore water pressure

Standard Penetration Test

involves driving a standard thick-walled sample tube into the ground at the bottom of a borehole by blows from a slide hammer with standard weight and falling distance

N value

SPT blowcount value or standard penetration resistance

relative density

the N value provides an indication of the _____ of the subsurface soil and it is used in empirical geotechnical correlation to estimate the approximate shear strength properties of the soils

Very loose

SPT N < 4

Loose

SPT N = 4 to 10

Medium dense

SPT N = 10 to 30

Dense

SPT N = 30 to 50

Very dense

SPT N > 50

specific weight

used to characterize the heaviness or density of material

capillary action

results from the combination of cohesive and adhesive forces, allowing liquids to move through narrow spaces against gravity

metacentric heigh

measure of the stability of a floating body

center of gravity of the body

metacentric height measures the distance between the _____ and metacenter

metacenter

point where the buoyant force acts vertically upwards when the body is tilted slightly from its equilibrium position

stable equilibrium

M is above G

its original position

in stable equilibrium, a small tilt will generate a righting moment that returns the body to

overturn

in unstable equilibrium, a small tilt will

unstable equilibrium

M is below tG

neutral equilibrium

M is at the same level as G

hydraulic gradient

represents the total energy at any given point in a pipeline system due to the elevation head and pressure head in the system

mass

continuous flow of fluid is based on the law of conservation of

barometer

instrument used to measure atmospheric ressure

mercury barometer

uses a column of mercury in a glass tube. atmospheric pressure pushes down on a reservoir of mercury causing the mercury to rise in the tube

aneroid barometer

uses a small, flexible metal box with dial to measure atmospheric pressure