DLY-1 coarse-grained soil vertical permeability deformation instrument - Database & Sql Blog Articles

DLY-1

Coarse grain vertical permeability analyzer

This test is in accordance with

DL/T5356-2006

The test procedure for coarse-grained soil in hydropower and water conservancy projects. The test method uses osmotic water flow from bottom to top and is suitable for coarse-grained soil. It is used to determine the permeability coefficient, dry density, porosity, osmotic gradient, and seepage flow rate of coarse-grained soil.

Technical Parameters

1,

Test tube specifications:

Ñ„

30

0

Mm

2,

Test tube height:

340

Mm

3,

Water supply tank specifications: Ñ„

510

Mm, height

500

Mm

4,

Measuring cylinder:

1000ML

5,

Measuring cylinder:

100ML

6,

Total Weight:

Instructions:

1,

Connect the lower water inlet to the water supply pipe to fill the instrument with water, check the instrument

Whether the components of the device are blocked or leaking. After the inspection is completed, lower the water supply tank so that the water level in the instrument is flush with the lower edge of the lower water permeable plate.

2,

Remove the top cover, lay the filter on the lower permeable plate, and apply a ring of water stop material along the contact gap between the barrel wall and the filter.

3,

Open all pressure taps to vent them.

4,

Sample should be divided

3

~

5

Layer loading, the gradation of each layer should be the same. Filling layer thickness: sand soil can be

2

Cm~

3

Cm; gravel soil can be sample size

1.5

~

2

Times. If necessary, add the equivalent of the sample quality

1%

~

2%

The water is mixed and even after filling.

5,

Each of the weighed samples is evenly layered into the measuring cylinder, compacted with a compacting hammer and reached the required height, and vibration encryption can be used for the weathered stone slag or the crushed earth material.

6,

The sample is saturated in the instrument using a capillary saturation method. Adjust the height of the water supply tank so that the water level of the water supply tank is slightly higher than the bottom surface of the sample, and the water supply tank is slowly raised.

1

Cm, should be stable

10min

After lifting the water supply tank. As the water level of the sample rises, the corresponding pressure measuring tube is turned on, and the sample is fully saturated and saturated until the water overflows the water outlet. At this time, the water level of each pressure measuring tube should be flush with the water level of the water outlet.

7

According to the fine particle content in the sample, the failure form of the sample seepage deformation is preliminarily judged: when it is a tube failure form, the initial slope of the infiltration should be

0.02

~

0.03,

Increment value

0.05, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50,

0.70, 1.00, 1.50, 2.00

, later press

1.00

~

2.00

Incremental, when approaching the critical slope, the incremental value of the osmotic gradient should be reduced as appropriate; when it is in the form of fluid failure, the value can be increased appropriately.

8

Raise the water head one by one according to the above regulations. After each rise of the water head, the outlet water should flow out

30min

~

60min,

After the water flow is stable, the water level of each pressure measuring tube is measured and the amount of water seepage is measured by the measuring cylinder. The number of readings and readings under each level of water head should not be less than three times. The interval between each reading and reading should be determined according to the amount of water seepage.

10min

~

20min,

At the same time, the temperature of the inlet and outlet water is measured. When the water level and water permeability of the three readings are basically stable, the water head can be raised to the next level. Take the three average values ​​close to the reading as the test values. For non-pipes, the time can be extended.

9

Observe the various phenomena that occur during the test, such as the degree of turbidity of the effluent, the bubble emerging, the fine particles jumping, moving or being carried out by the water flow, the suspension of the soil, the seepage flow and the change of the water level of the pressure measuring tube, etc. A detailed description. When a critical slope occurs or the precursor of the slope is destroyed, the incremental value of the slope should be adjusted in time.

10

When the sample is damaged or the water head can no longer continue to increase, the test can be ended. For permeation tests that require only a determination of the permeability coefficient, continue to apply after a critical slope has occurred

1

~

2

The test was terminated after the level of water head.

11

After the test is finished, close the nozzle, draw the remaining water on the sample, observe the sample change, and test the height of the sample according to the required amount. The sample with load should be unloaded in time and observe the rebound condition. Remove the top cover, absorb the residual water on the sample, and remove the upper permeable plate. Release the remaining water from the instrument and remove the sample. Test the particle grading after the test as needed.

12

At the same time as the test, it is advisable to plot the relationship between the osmotic gradient and the seepage velocity. Taking the osmosis slope as the ordinate and the seepage velocity as the abscissa, draw on the double logarithmic coordinate paper, and if necessary, plot the seepage velocity versus time. According to the curve change, the duration of each stage head and the level difference of the head are adjusted in time.

The results of the test should be consistent

DL/T5356-2006

Claim.

The test is cleaned up for the next use.