Casagrande & Standpipe Piezometer

Casagrande & Standpipe Piezometer

Casagrande piezometers are used for measuring pore water pressure in medium to low permeable soils. The Casagrande piezometers consist of a filter unit that is connected to the surface using a single or twin tube. The filter can be installed with a bentonite seal at the top and sometimes at the bottom of the filter. For easy maintenance, a twin tube configuration allows for internal flushing of the filter.

Standpipe piezometers are designed to monitor the groundwater table level in high permeability soils. The filter unit is typically made up of a Casagrande filter or a slotted tube covered with geotechnical fabric for filtered water entry. The standpipe piezometer is connected to the surface with tubes and can be read using a portable water level meter or automatically with a pressure transducer.

The Casagrande and Standpipe piezometers are ideal for monitoring ground water levels, hydrological investigations, stability control of embankments, and performing permeability tests in dewatering activities.

Typically, the user should select bill of materials based on deployment scenario:

• Casagrande Filter Unit: A key component of the piezometer, the Casagrande filter allows for the measurement of pore water pressure in low permeability soils.
• Slotted Tube with Geotextile Filter (Standpipe Piezometer): Used for standpipe piezometers to monitor groundwater levels in permeable soils.
• Bentonite-Cement Ground: A sealing material used during installation to ensure that the piezometer remains in place and prevents contamination from surrounding soil.
• Geotextile Filter: A filter material used in piezometer installations to Prevent soil particles from entering the piezometer, ensuring accurate pressure readings.
• Water Level Meter: A portable device used to manually measure the water column in the piezometer to measure the water level in standpipe piezometers.

Applications of Casagrande and Standpipe Piezometers

• Control of Ground Water Level: Used to monitor changes in groundwater levels over time.
• Hydrological and Water Supply Investigations: Essential for studying groundwater flow and water resources.
• Construction and Stability Control: Used in the construction of embankments, earth dams, and foundations to ensure structural stability.
• Investigation of Stability in Natural and Cut Slopes: Used to assess the stability of slopes in both natural and engineered environments.
• Permeability Tests for Drainage and Dewatering Activities: Assists in evaluating the permeability of soils for drainage and dewatering purposes.