Geosynthetics direct shears - Huaqiang Electronic Network

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First, the scope of application of geosynthetics direct shear

The geosynthetics direct shear tester determines the friction characteristics of the sand/geotextile interface by testing the standard sand/geotextile contact surface. This instrument is suitable for all geotextiles and related products. The instrument uses a high precision servo motor.

[Standards compliant]:

ISO12957.1, GB/T17635.1, ASTM D5321, JTGE50T1129, 2006, SL/T235-2012, GB17642-2008

Second, geosynthetics direct shear instrument technical parameters

1, the cutting box size 300 × 300mm

2, the force range 0 ~ 30KN

3, normal pressure 50KPa 100KPa 150KPa 200KPa

4, horizontal shear rate 0.02 ~ 3mm / min

5, horizontal shear displacement 0 ~ 50mm

6, Dimensions: 1170X580X1600mm

7, the power supply AC220V50Hz

Third, geosynthetics direct shear test method

1. The sample is laid flat on a rigid horizontal base located in the lower portion of the shear box with the front end clamped in front of the shear zone. The sample is bonded to the base by glue. After bonding, the specimen should be flat, without folds and wrinkles. Relative slippage between the sample and the base is not allowed during the test.

2. Install the cutting box: Fill the upper cutting box with the standard sand of the pre-standard quality (Note: the standard sand user-supplied), and fill the thickness of 50mm. The thickness of the sand should be uniform, and the dry density after compaction is 1750kg/m3.

3. Install the horizontal loader and apply a normal pressure of 50KPa to the sample.

4. Apply a horizontal load so that the corresponding displacement between the upper and lower shear boxes is 1 mm/min ± 0.2 mm/min. The shear force T is measured continuously or indirectly, and the corresponding relative displacement ΔL is recorded at the same time, and the interval time is 12 S. The start can also be encrypted as the case until the end of the shear plane length is 16.5%.

5. Operating steps of the liquid crystal table:

1) Turn on the power switch

2) Press the function key to open the new test

3) Enter the speed required for the test and press the enter key

Screen display: "shear force", "shear stress", "peak", "displacement".

4) Press the start button to start the test (ie: incremental stress, the first test normal stress 50KPa, the result is valid, automatically enter the next 100KPa, 150KPa and 200KPa)

5) When the displacement starts counting, when the total contact surface is 16.5%, the test is completed, the machine stops automatically, and the test data results are displayed. If the test is correct, press the confirm button.

4. Geosynthetics Direct Shears After the end of each work class, the countertops should be completely cleaned. Do the maintenance of the machine for the next operation.