Railway standard coarse-grained soil permeameter with constant water head for vertical infiltration of granular soil

Railway standard coarse-grained soil permeameter with constant water head for vertical infiltration of granular soilUsed for measuring large particle sizes not exceeding75mmThe permeability coefficient of coarse-grained soil and graded crushed stone. This device complies with the new standardTB10751-2018Construction Quality Acceptance Standards for High speed Railway Roadbed Engineering.

Product Technical Parameters

Water supply tank capacity:80 L；

Inner diameter of metal cylinder:300 mm；

Metal cylinder height:500mm；

Metal cylinder wall thickness:10 mm；

Number of pressure measuring tubes: 5；

Internal diameter of pressure measuring tube:8 mm；

Scale division value of pressure measuring tube:1 mm；

Distance between pressure measuring holes:50 mm；

Diameter of seepage hole:16 mm；

Inner diameter of overflow pipe:16 mm；

透水板孔径：3.5 mm；

Instructions for use

1. Install the instrument and check if there is any water leakage at the joints of each pipeline. Connect the regulating pipe to the water supply pipe, fill the bottom of the instrument with water until the water level is slightly higher than the metal orifice plate, and close the water clamp.

2. Take a representative air dried sample of 2500g and weigh it accurately to 1.0g.

3. Place the sample in layers into a cylinder, with each layer 2-3cm thick, and gently compact it with a wooden hammer to a certain thickness to control its porosity.

4. After each layer of the sample is installed, connect the water supply pipe and the regulating pipe, and let water enter through the regulating pipe. Slightly open the water stop clamp to gradually saturate the sample. When the water surface is level with the top surface of the sample, close the water clamp. When saturated, the water flow should not be too fast to avoid impacting the sample.

5. Install the sample layer by layer according to the above steps until the sample is 3-4cm higher than the upper pressure measuring hole. Place a metal orifice plate as a buffer layer at the top of the sample. After the next layer of the sample is saturated, continue to slowly raise the water level to the overflow hole. When water overflows, close the water clamp.

After the sample is installed, measure the remaining height from the top of the test sample to the upper opening of the instrument and calculate the net height of the sample. Accurately weigh the remaining sample mass to 1g and calculate the total mass of the loaded sample.

After standing for a few minutes, check whether the water level of each pressure measuring tube is level with the overflow hole. If it is not level, it indicates that there is a gas collection barrier in the sample or at the joint of the pressure measuring tube. Use a water absorbing ball to absorb water and exhaust the gas.

8. Raise the regulating pipe above the overflow hole. Then separate the regulating pipe from the water supply pipe and place the water supply pipe inside the metal cylinder. Open the water stop clamp to allow water to be injected into the metal cylinder from the top.

9. Lower the regulating pipe opening to the upper one-third of the sample, causing a water level difference. Water seeps through the sample and flows out through the regulating tube. During the infiltration process, the clamp of the water supply pipe should be adjusted so that the flow rate of the water supply pipe is slightly higher than the overflow amount. The overflow hole should always have excess water overflowing to maintain a constant water level.

10. After the water level of the pressure gauge tube stabilizes, record the water level of the pressure gauge tube. Calculate the water level difference between each pressure measuring tube.

11. Start the stopwatch and use a graduated cylinder to measure the amount of water that has been seeping in for a certain period of time, and repeat once. When receiving the amount of permeate, the regulating pipe mouth must not be submerged in water.

12. Lower the regulating pipe mouth to the middle and lower parts of the sample to change the hydraulic slope. Repeat the measurement according to regulations 10 and 11

Railway standard coarse-grained soil permeameter with constant water head for vertical infiltration of granular soil

Used for measuring large particle sizes not exceeding75mmThe permeability coefficient of coarse-grained soil and graded crushed stone. This device complies with the new standardTB10751-2018Construction Quality Acceptance Standards for High speed Railway Roadbed Engineering.

Product Technical Parameters

Water supply tank capacity:80 L；

Inner diameter of metal cylinder:300 mm；

Metal cylinder height:500mm；

Metal cylinder wall thickness:10 mm；

Number of pressure measuring tubes: 5；

Internal diameter of pressure measuring tube:8 mm；

Scale division value of pressure measuring tube:1 mm；

Distance between pressure measuring holes:50 mm；

Diameter of seepage hole:16 mm；

Inner diameter of overflow pipe:16 mm；

透水板孔径：3.5 mm；

Instructions for use

1. Install the instrument and check if there is any water leakage at the joints of each pipeline. Connect the regulating pipe to the water supply pipe, fill the bottom of the instrument with water until the water level is slightly higher than the metal orifice plate, and close the water clamp.

2. Take a representative air dried sample of 2500g and weigh it accurately to 1.0g.

3. Place the sample in layers into a cylinder, with each layer 2-3cm thick, and gently compact it with a wooden hammer to a certain thickness to control its porosity.

4. After each layer of the sample is installed, connect the water supply pipe and the regulating pipe, and let water enter through the regulating pipe. Slightly open the water stop clamp to gradually saturate the sample. When the water surface is level with the top surface of the sample, close the water clamp. When saturated, the water flow should not be too fast to avoid impacting the sample.

5. Install the sample layer by layer according to the above steps until the sample is 3-4cm higher than the upper pressure measuring hole. Place a metal orifice plate as a buffer layer at the top of the sample. After the next layer of the sample is saturated, continue to slowly raise the water level to the overflow hole. When water overflows, close the water clamp.

After the sample is installed, measure the remaining height from the top of the test sample to the upper opening of the instrument and calculate the net height of the sample. Accurately weigh the remaining sample mass to 1g and calculate the total mass of the loaded sample.

After standing for a few minutes, check whether the water level of each pressure measuring tube is level with the overflow hole. If it is not level, it indicates that there is a gas collection barrier in the sample or at the joint of the pressure measuring tube. Use a water absorbing ball to absorb water and exhaust the gas.

8. Raise the regulating pipe above the overflow hole. Then separate the regulating pipe from the water supply pipe and place the water supply pipe inside the metal cylinder. Open the water stop clamp to allow water to be injected into the metal cylinder from the top.

9. Lower the regulating pipe opening to the upper one-third of the sample, causing a water level difference. Water seeps through the sample and flows out through the regulating tube. During the infiltration process, the clamp of the water supply pipe should be adjusted so that the flow rate of the water supply pipe is slightly higher than the overflow amount. The overflow hole should always have excess water overflowing to maintain a constant water level.

10. After the water level of the pressure gauge tube stabilizes, record the water level of the pressure gauge tube. Calculate the water level difference between each pressure measuring tube.

11. Start the stopwatch and use a graduated cylinder to measure the amount of water that has been seeping in for a certain period of time, and repeat once. When receiving the amount of permeate, the regulating pipe mouth must not be submerged in water.

12. Lower the regulating pipe mouth to the middle and lower parts of the sample to change the hydraulic slope. Repeat the measurement according to regulations 10 and 11