Soil Mechanics Final |113 questions| with correct answers

What is the sieve number that is used to separate fine sand from medium sand? CORRECT ANSWER 40 What is the grain size diameter (in mm) that is the dividing line between fines and sand particles sizes? CORRECT ANSWER 0.075 TF: The diffuse double layer is the basic structure of each clay particle, and these clay particle diffuse double layers are the 2 different mineral sheets bonded together CORRECT ANSWER False. The diffuse double layer is the region of attracted positive ions in solution and the negatively charged surface of the clay The plastic limit test involves rolling out a soil thread until it just breaks into smaller pieces when thread is what diameter? CORRECT ANSWER 1/8 inch List the 4 conditions necessary for Liquefaction to occur in a natural sand deposit CORRECT ANSWER Loose soil, fine sand, below GWT, earthquakes TF: A clay soil is considered to be at its liquid limit when the slot closes for 1/2 inch of its length at 35 drops of the brass cup CORRECT ANSWER False. 25 drops TF: All the clay soils exhibit the same behavior and shear strength when at their Liquid Limit, even if one clay has LL=130% and another clay has LL=25% CORRECT ANSWER True List the three most common clay minerals that were discussed in class CORRECT ANSWER Montmorillonite, Kaolinite, Illite Which common clay mineral has the most potential for shrink and swell when water content changes? CORRECT ANSWER Montmorillonite