Soils Midterm 1 Page 4
Show all work. Read the questions carefully before you answer.
3 points per question, 1 point for your name.
1. What are the three main categories of rock from a geologic view (the three types in the Rock Cycle), and how are they formed?
2. Plot and calculate the LL of the following data (#blows, %m): (9,40), (15,37), (35,33), (36,30). Show the CORRECT graph.
3. What are the two kinds of processes that break rock down into sediment? Briefly describe.
4. Two types of geologically deposited soils:
a. Residual and excavated
b. Silty and windy
c. Residual and transported
d. Brown and gray
e. Colluvium and Archastic
5. The four major types of soils (in terms of particle size) in construction are:
6. If a soil sample starting dry weight is 400 grams, it is washed through a #200 sieve and dried, and weighed again at 340 grams, what is the soil’s LBW ? Show work.
7. The 3 main physical states of clay (in a volume-moisture relationship) are ______________, _____________, and ______________.
8. How many blows per second is the liquid limit device cranked?
9. What is “PI”? How is PI calculated? If an LL is 35 and PL is 20, what is the PI?
10. Liquid Limit is the lower moisture limit of what state of clay? Draw the diagram showing the moisture contents vs. states of clay.
11. In the PL test, what is the diameter of the thread that we must roll that determines the PL moisture? What is the ASTM standard that tells you that?
12. Define “Fat Clay” and “Lean Clay”
13. The three types of physical materials (volumes) in a soil phase diagram are:
14. If the WATER in a phase diagram is ZERO, the soil is what state?
15. Describe IN DETAIL a modified Proctor test, including mold and hammer description, and procedure, including lifts and calculations for ONE POINT on the curve.
16. Ww is 13#, Ws is 130#, Vt is 1.3 cubic feet, what is dry unit weight?
17. In the above question, what is Wt ?
18. Vv= (Volume of Voids) is? (Circle all that apply):
a. VA+VS
b. WA+VA
c. VA+VW
d. Vt-VS
e. WA+VW
19. The following is data from a PL test. PL is___________
| Tin # | 73A |
| Tare | 6.31g |
| Wet + tare | 34.53g |
| Dry + tare | 24.65g |
20. If a sieve test is run with the #8 sieve accidently place above the #4 sieve instead of below it, how would this affect the contents of the two sieves?
21. Can a Liquid Limit test be run on sand? Yes or No
22. ASTM is an abbreviation for_________ ________ for _________ and __________
23. What is the nominal opening size of one opening in a #8 sieve mesh?_____” x _____”
24. What are two ways a Standard Proctor is different from a Modified Proctor?
25. If an object’s density is 150 pcf, what is its Specific Gravity?
26. The “spaces” between solid soil particles are called __________, and can be filled with _______ or _________.
27. LBW stands for ___________ by ______________.
28. Clay strength is primarily due to :
a. Capillary Forces
b. Shear Forces
c. Cohessive Forces
d. Granular Forces
e. Pressure Forces
f. Special Forces
29. Sand strength is due primarily to:
a. Armed Forces
b. Capillary Forces
c. Shear Forces
d. Cohessive Forces
e. Frictional Forces
f. Pressure Forces
30. Silt is Granular or Cohesive? CIRCLE ONE
31. _________________ receding from the last Ice Age deposited many of the soils found in northern North America. (“ice” is not the answer…..).
32. 400.0 grams into the sieve stack yield the following results: (Double Point Question). Show ALL work.
| Sieve # | wt retained | % Retained | % Passing |
| 30 | 0 | ||
| 50 | 160.0 | ||
| 100 | 120.0 | ||
| 200 | 80.0 | ||
| Pan | 40.0 | ||
| Total | 400.0 | 100.0 | x |