A self-contained, fl oor-standing unit consisting of a tank with tappings connected to a bank of piezometer tubes. It demonstrates fl ow through permiable media with common structures, such as dams and walls.
Key features
• Visualisation and measurement of fl ow through permeable media
• Dye-injector system to help show fl ow lines
• Clear plate glass resists abrasion and allows students to see fl ow patterns
• Includes pressure tappings and piezometer tubes to measure head distribution
• Plates supplied to simulate models of walls, sheet piling and dams
• Includes adjustable overfl ow pipes to vary the head across the models
• Self-contained, fl oor-standing unit – only needs water supply and drain
Description
The apparatus is a transparent-sided tank, mounted on a steel-framed bench with worktop.
The tank is clear so students can see the fl ow patterns. The sides are plate glass to resist abrasion from the permeable medium. The rear of the tank contains pressure tappings. Each tapping has fi lters that stop any unwanted particles. The tappings connect to a bank of piezometer tubes at the side of the apparatus which allow measurement of the head distribution along the tank.
Removable stainless-steel mesh baffl es at each end of the tank hold the permeable medium (usually sand) in place. At each side of the baffl es are end compartments with adjustable overfl ow pipes for setting the water levels at each end of the model. The top of the tank is open to allow students to fi ll the tank and set up model structures. Supplied are clear, self-sealing plates for students to build models of sheet piling, walls and simulated dams.
Included is a dye-injector system to help show fl ow lines. Around the front edge of the glass tank are scales to help students position and measure fl ow nets correctly. The self-contained apparatus needs only a mains water supply and drain.
Recommended Ancillary
• Permeable Medium (H312a) – Washed sand, graded 0.5 mm to 1.5 mm (nominal 1 mm)
Learning outcomes
• Determination of seepage beneath a structure
• Construction of fl ow nets and determination of coeffi cient of permeability
• Flow under a sheet pile and determination of critical seepage force at which ‘piping’ occurs
• Seepage fl ow under an impermeable dam
• Flow through an earth dam with and without a toe drain
• Drawdown in horizontal fl ow (simulation of ground water fl ow into a river or well)
• Determination of uplift pressures on structures such as building foundations
• General studies of seepage and drainage
• Flow through a porous medium (Darcy’s law)
