"High-speed railway subgrade engineering construction quality acceptance standard"
TB 10751-2018 (Summary of Appendix)
Appendix C Permeability Test Method of Coarse Grained Soil
C.0.1 This permeation test method is used to determine the permeability of coarse-grained soil and graded gravel with a maximum particle size of not more than 75mm
Permeability coefficient k. For coarse-grained soil with a maximum particle size of not more than 10mm, the "Regulations for Railway Engineering Geotechnical Test"
The constant head method in (TB 10102) measures the permeability coefficient k.
C.0.2 The test water should be clean natural water, and the air extraction method or boiling method should be used for degassing before the test. test
During the test, the water temperature should be 3℃~4℃ higher than room temperature.
C.0.3 The equipment used in this test should meet the following requirements:
1 Normal head permeameter device:
The inner diameter of the back cover metal cylinder is 300mm, the height is 500mm, and the wall thickness should not be less than 10mm; inside the glass pressure measuring tube
The diameter should be 6mm, the graduation value is 1mm; there are five pressure measuring holes, numbered from top to bottom as 1#, 2#,
3#, 4#, 5#, the spacing of pressure measuring holes is 50mm; the diameter of the seepage hole should not be less than 15mm; inside the overflow pipe
The diameter should not be less than 15mm; the permeable plate is divided into upper permeable plate and lower permeable plate, the aperture of the permeable plate should be selected
3mm~5mm. Adjusting pipes and overflow pipes should use rubber pipes that match the seepage holes and overflow holes.
2 Platform scale: weighing 30kg, the division value is 1.0g.
3 Measuring cylinder: the volume is 1000ml.
4 Thermometer: the graduation value is 0.5℃.
5 Compaction hammer: mass 9kg ±100g, diameter 100mm.
6 Other accessory equipment: stopwatch, steel ruler, rubber tube, adjusting tube, bracket with ruler, water bucket
Wait.