Question

done.

Answer 1

you have a series of values, and need to create ratios out of them. Line up the units you have to make the ratios you're asked for.

Answer 2

no idea

Answer 3

@eyust707

Answer 4

Dry unit weight = weight of solids/volume total

Answer 5

Void ratio = Specific gravity* Unit weight of water/(dry unit weight) - 1

Answer 6

Porosity = e/(1 + e)

Answer 7

Saturation = moisture content* S.G./e

Answer 8

I wouldn't memorize how to derive these just practice how to use and navigate through them given various parameters. I got these from my soils book.

Answer 9

In your book there should be a section on relationships of soil properties.

Answer 10

units are English units

Answer 11

a is unitless
b is lbs/ft^3
c is lbs/ft^3
d is unitless
e is unitless
f is unitless

Answer 12

numbers look very high on some of those

Answer 13

typically soil is 90-160 lbs per cubic foot

Answer 14

moisture content is usually expressed as a percent

Answer 15

okay i'll redue it and get back with you on it.

Answer 16

@eyust707
a)15%
b)120lbs/ft^3
c)104.4lbs/ft^3
d)5.29
e).84
f)94

Answer 17

@eyust707

Answer 18

oh i might have confused you a little with the S calculation.

Usually (unless stated otherwise) when you plug in a percent like "15%" to an equation you should plug in ".15" not 15.

Answer 19

One thing I do to help myself not only become a better student but to also become a better engineer is to constantly ask the question, "does this make sense?" or "is this answer practical?"

The answer you put for f.) is a good example where this might have saved you.

Degree of saturation is a ratio between the volume of the water in the soil sample to the volume of the voids (all the air pockets) in the soil sample. S = Vw/Vv Can there ever be more water than there are air pockets?

Probably not. Therefore S can never be more than 1. If you do get an answer more than 1 you probably made a mistake.

Using this logic more and more you'll be able to tell if your answer is possibly correct or not definitely incorrect without ever even doing the math.

Answer 20

hehe i wasn't going to calc these out but I'll do it since you seem like a great student and very dedicated.

Answer 21

uh i see. I'm guessing to that all my calculations might be off then?

Answer 22

yes yes I made a typo in my formula I gave you

Answer 23

I'm sorry

Answer 24

e = G.s * Unit weight of water/dry unit weight - 1

Answer 25

Here's the values I got
a. .15 or 15%
b. 120 lbs/ft3
c. 104.4 lbs/ft3
d. .572
e. 0.36
f. 0.69

Answer 26

okay i will see where i went wrong. I might have even used the wrong numbers for the last three...

Answer 27

Heres a few things to keep in mind:

Moisture content is a percentage that indicates how mush weight of water is in the sample.

Void ratio: A that tells you how much of the sample is air pockets compared to how much of the sample is solid. e = 1 would mean for every 1 air pocket theres the same volume in soil. e = .5 would mean there are half the amount of voids than there are dry solids.

Porosity: very similar to void ratio. This is the volume of the voids in relation to the total volume of the sample. Porosity can never be more than 1. n =1 the sample is only air, n=0 the sample has no voids.

Degree of saturation: How saturated is the sample? S = 1 would mean the sample is completely saturated. S=0 wouldn't mean the sample is completely dry.

Answer 28

@eyust707 don't mean to bother you but when i get this right i will leave it at that. but i am still having trouble getting the last three d,e,f and i have redone them and still don't get the correct answer.
d) 2.62*62.4/26.1-1= did not get the same thing
e) e/ 1+e= did not get the same thing
f)30*2.62/e= did not get the same thing.

what on earth could i be pluging in wrong with my numbers?

Answer 29

2.62* 62.4/104.4 - 1

Answer 30

G.s * unit weight of water/dry unit weight - 1

Answer 31

okay so for d) i get .572 and for e) i get .36. but f) i'm plugging in something wrong as well?

Answer 32

for f) is it 0.25/.36=?

Answer 33

Saturation = moisture content* S.G./e

Answer 34

Saturation = .15 * 2.63/ .572 = .39/.572 = .68

Answer 35

oh okay i will keep practicing this until it becomes natural to me. thanks for being patient with me and explaining the material the best way you could. I appreciate it. @eyust707