PERMFILE131137

• Permit No: C1980005
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: LABORATORY PROCEDURES
• Section_Exhibit Name: TAB 06 APPENDIX 6-2
• Media Type: D
• Archive: No

PROCEDURE FOR DETEP`4INATION OF
0.3 AND 15 ATMOSPHERE PRESSURE POINT
1. Preparatory Steps:
a. Sieve soil samples through a 8 mesh screen.
b. Pre-soak the porous plate for 2 hours inside the
pressure chamber.
2. Procedure for setting up the pressure chamber:
a. Place the sample. retainer rings on the porous plate.
b. Pour a soil sample into each rings, level with the top.
c. Allow the samples to stand at least 16 hours with
an excess of water on the plate.
3. At 8:00 a.m. the following day:
a. Remove excess water fro-i the membrane with a pipet
or rubber syringe.
• b. Close the pressure membrane apparatus and admit air
to the soil chamber at a pressure of 1/3 atmosphere
(5 p.s.i.). When running 15 atmosphere pressure
point apply a pressure of 15 atmosphere (220 p.s.i.).
c. Remove the samples when the readings on an outflow
buret indicate equilibrium has been attained. Some
soils will approach equilibrium in 18 to 20 hours.
d. Before releasing the ai= pressure in the pressure
cooker, put a pinch claap on the outflow tube on
each plate. This prevents backflow of water to the
samples after the pressure is released.
e. To avoid changes in the moiiture content of the
samples, transfer the samples quickly to previously
weighed soild moisture cans.
f. Determine the moisture content by drying to constant
weight at 105°C. Express the moisture content as
percent, dry weight basis.
4. Calculate ~ moisture remaining after 1/3 atmosphere or 15
atmosphere•
a. Subtract oven-dry weight of soil plus can from moisture
weight of soil plus'can. This gives weight of water
remaining after 15 atmosphere pressure.
b. Subtract weight of can`_ron oven-dry weight of soil
plus can.
6-68