CE 540 HW

 

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Mon. Well
 

CE En 540
Homework #4

Soil Compaction Specifications

A series of density tests were performed on a soil which is being considered for use on a clay liner at a landfill.  Assume Gs=2.60.  The results of the tests are as follows:

Modified Proctor Test

Samp. #

w [%]

gd [pcf]

k [cm/s]

Su [psf]

1

2.3

114.4

4.5 X 10-7

3250

2

4.7

117.3

2.0 X 10-7

3300

3

8.0

119.3

3.0 X 10-8

3280

4

12.0

117.2

3.2 X 10-9

3030

5

15.0

113.2

2.6 X 10-9

2550

Standard Proctor Test

Samp. #

w [%]

gd [pcf]

k [cm/s]

Su [psf]

1

7.6

106.1

4.1 X 10-6

2530

2

9.7

109.4

3.0 X 10-6

2600

3

12.6

110.3

4.0 X 10-7

2570

4

16.0

109.2

1.0 X 10-8

2200

5

18.5

105.9

5.0 X 10-9

1830

Reduced Proctor Test

Samp. #

w [%]

gd [pcf]

k [cm/s]

Su [psf]

1

11.0

98.3

8.1 X 10-6

1720

2

12.4

100.7

7.2 X 10-6

1790

3

14.4

102.3

3.2 X 10-6

1800

4

18.2

103.0

7.0 X 10-8

1650

5

22.0

99.2

1.0 X 10-8

1020

All of the plotting/data manipulation described below should be done in Excel.

Using the data shown above, generate the following:

1. A plot of K vs. w (using a log scale for K).

2. A plot of gd vs w that includes the following:

(a) gd vs w curves for each of the three tests.

(b) zero air voids curve

(c) line of optimums (Draw this line using the curve tool in the Drawing toolbar)

(d) contours of Su at interval of 500 psf.  (Draw these lines using the curve tool in the Drawing toolbar)

(e) A shaded polygon representing the acceptable zone for construction which ensures that the EPA requirements for K (<10-7 cm/s) will be met. The zone should also ensure that Su >= 1500 psf.

Draw the polygon using the freeform tool in the Drawing toolbar.  Fill the polygon with a transparent color).

When picking the left boundary of your zone, you will need to select a minimum moisture content.  Just pick a value that encloses your measured sample values that have sufficiently low K. I have never heard a good explanation for how to determine the lower limit here.

In case you have forgotten, the zero air voids curve can be found using the following equation:

 

Submittal Instructions:

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