SAMPLING WITH PISTON SAMPLER AND OBSERVATION OF WATER TABLE Flashcards
______________ are thin walled equipment that come in various types to obtain undisturbed soil samples. Its main distinction is the use of pistons to maintain soil integrity.
Piston samplers
advantage of piston sampler where you have precise control over the sampling depth
precision
is created which helps retain sample
during withdrawal in piston sampler
vacuum
typical sampling depth of piston sampler
0.75-2m
a phenomenon where the piston in the piston sampler will stop from moving after encountering stiff soils
piston seizure
is the upper boundary of the underground zone of saturation, where the soil and rocks are permanently filled with water.
water table
WHY IS IT NEEDED TO
EXPLORE/OBSERVE WATER TABLE?
-foundation design
-soil stability
main water table in an area,representing the upper surface of the zone ofsaturation in the primary aquifer
REGIONAL WATER TABLE
occurs when a localized zone of saturation sits above the regional water table
perched water table
specially constructed wells designed to monitor groundwater levels over time.
observation wells
type of measurement in water table observation where Using a tape or water level meter to
measure water levels manually.
Manual Measurement
type of measurement in water table observation where Equipped with sensors for
continuous recording of water levels.
Automated Monitoring:
Specialized instruments
measuring pressure head of
groundwater in confined
aquifers.
PIEZOMETERS
MEASUREMENT AND
TECHNIQUES FOR PIEZOMETERS where Determines height of water
above a reference point.
Hydraulic Head Measurement
MEASUREMENT AND
TECHNIQUES FOR PIEZOMETERS where
Equipped with sensors for continuous logging
of groundwater pressure fluctuations.
Data Logging:
Monitors
overall groundwater levels using a
slotted pipe with gravel/sand
packing
Observation Well:
Measures water
pressure at a specific depth with
a screened section and bentonite
seal.
Piezometer:
