Geosynthetics puller test method - Database & Sql Blog Articles

Single chip microcomputer STM32L151CCU6

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Determination of geosynthetics by testing the frictional resistance of geosynthetics and surrounding soils

Pulling resistance characteristics. Suitable for all kinds of soil and state soil and various types of geotextiles, geomembranes, geotechnical belts and geogrids.

[[Standards compliant]:

ISO12957.1, GB/T17635.1, ASTM D5321, JTGE50T1129, SL/T235-2012

Features:

1 using stepper motor shear rate accuracy

2 Normal pressure is easy to use and pressurized

3 large screen LCD controls,

4 can be connected with the microcomputer to achieve computer control, print reports

Two [technical parameters]:

l Pulling box inner diameter 290 × 290 × 290 mm

2 force accuracy error ≤ ± 0.3%

3 Force range 0 to 10 KN

4 normal pressure 0～200 kPa

5 horizontal drawing rate 0.5mm/min

6 horizontal pull displacement 0 ~ 30mm

7 Displacement accuracy error ≤ ±0.3%

8 power supply 220V 50Hz

experiment method

1 Cut the specimen according to the provisions. The width of the specimen should be slightly smaller than the width of the test chamber. The length of the specimen should be such that the specimen is not broken and determined by the test.

2 Each group of tests should be no less than 3 samples.

3 The end of the sample taken from the test chamber shall be reinforced, and the sample outside the box shall not be deformed greatly during the test.

4. Carefully fill the soil in the lower half of the test box according to the density and condition of the design. The fill height is flush with the seam and level the surface.

5 Place the sample on the soil surface, and draw the end from the seam. Pay attention to the symmetry of the two sides, then gently lay a layer of soil on the sample to position the sample.

6 Fill the soil in the upper half of the box according to the density and condition required by the design.

7 Place the end of the specimen flat into the tension clamp and center it evenly.

8 Put the top cover and the dial indicator in turn, apply the normal pressure, and the time required for consolidation can be carried out according to the relevant test procedures.

9 Adjust the horizontal loading device and press the LCD display Chinese display. The test parameters required for the test are performed in sequence. Start the test. The up and down arrow keys are used to adjust the desired position of the fixture. The pull start point is when the tension clamp begins to be stressed. Press the start button to read and record the displacement and horizontal pull. The drawing rate can be referred to the working test procedure, and it is preferable to take 0.5 mm/min for the sandy soil.

10 When the pull-out force peaks, continue drawing until the pull-out force is stable, and the test can be stopped.

11 Change one piece of specimen and apply another normal pressure. Repeat the above steps in this section to complete all tests.

Calculation

Calculate the interface pull friction strength as follows:

(17.5.1)

Ï„

p

- pull the frictional strength,

kPa

T _p

- the measured peak horizontal total pull,

kN

L

,

B

- the length and width of the specimen buried inside the soil,

m

17.5.2 Calculate the drawing friction strength under normal pressure at each level and plot the Ï„p~p curve.

17.5.3 Calculate the drawing friction coefficient f of soil-geosynthetic materials by the following formula:

f=

Ï„

p

/p

(17.5.3)

In the middle

p

- normal pressure,

kPa

Ï„

p

- corresponding to the drawing friction strength of σ,

kPa

The experiment is over. . . . . .