A constant head permeability test is performed on soil that is 2 cm x 2 cm square, and 2.5cm long. The head difference applied during the test is 20 cm and 7 cm3 is collected over a time of 100 sec. a) Compute the permeability based on these test conditions and results.  b) A falling head test is conducted on the same soil specimen at the same time  (t1 – t2 = 100 sec), and the standpipe diameter is 0.8 cm. If the average head during the test should be 18 cm, what are h1 and h2 values?

In a falling head permeability test on a soil sample of length 1₁, the head of water in the stand pipe takes 50 seconds to fall from 900mm to 135mm above the tail water level. When another soil sample of length 60mm is placed on the first soil sample, the time taken for the head to fall between the same limits is 150 seconds. The permeameter has a cross-sectional area of 4560 mm² and a stand pipe has an area of 130mm². The permeability of the second soil sample will be

(From Chapter 7) 6. A sample of normally consolidated clay was obtained by a Shelby tube sampler from the midheight of a normally consolidated clay layer (see Figure 7-34). A consolidation test was conducted on a portion of this sample, the results of which are given as follows: FIGURE 7-34 Water Table 9 ft. square Sand and Gravel Unit Weight = 120 lb/ft³ Normally Consolidated Clay Unit Weight = 103 lb/ft³ Gravel and Sand Unit Weight = 125 lb/ft³ p (tons/ft²) 0.250 0.500 1.00 2.00 4.00 8.00 16.00 e Elevation 100 ft 1.72 1.70 1.64 1.51 1.34 1.15 0.95 Elevation 94 ft 1. Natural (initial) void ratio of the clay existing in the field (eo) = 1.80. 2. Pressure-void ratio relationships are as follows: Elevation 85 ft Elevation 76 ft A footing is to be constructed 6 ft below ground surface, as shown in Figure 7-34. The base of the footing is 9 ft by 9 ft, and it carries a total load of 200 tons, which includes the column load, weight of footing, and weight of soil surcharge on the footing. a.…

A specific gravity test was performed on three soil samples, and the following data were collected: Material weight of empty pycnometer weigt of dry soil weight of weight of pycnometer pycnometer Temperature + water +water+soil g Sand 1 106.6 Sand 2 106.6 Sand 3 106.6 2-a) Briefly describe the test procedure and discuss its applications in practice 2-b) The corrected specific gravity of SAND 1 G5,20 2-c) The corrected specific gravity of SAND 2 G5,20 2-d) The corrected specific gravity of SAND 3 G5,20 55.4 50 60 === === g 385.5 371 392 351 340 355 с 18 24 20