Q2 Slopes And Yield

Question 1

How do you work out void ratio?

Answer 1

e = Vv/Vs = (V - Vs)/Vs

Question 2

How do you work out Volume of solids?

Answer 2

Vs = Ms/(Gs * Pw) = W/(Gs * Pw * 9.81)

also multiply by 10^6 if in grams to get cm^3

Question 3

How to work out friction angle?

Answer 3

Tan(PHI) = TAUmax/N

TAUmax may be taken from the graph, look at the data bitch

Question 4

Unconfined compression test, determine undrained shear strength Su

Answer 4

Find initial area Ao, find strain, then find area at failure Af.
Find the stress at failure SIGMA.f.
Finally, find Su

Question 5

How to determine initial area Ao

Answer 5

Ao = (PI * D^2)/4

Question 6

How to determine Area at failure Afail?

Answer 6

Af = Ao/(1-Strain)

Question 7

How to find stress at failure SIGMA.f

Answer 7

SIGMA.f = P/Af

Question 8

Find undrained shear strength of unconfined (last bit)

Answer 8

Su = (SIGMA.f - SIGMA.3)/2
Where SIGMA.3 is zero for an unconfined test

Question 9

BASICS: How to work out specific gravity Gs

Answer 9

Gs = GAMMA.s/GAMMA.w = Ps/Pw

Question 10

For an infinite slope with clay, what is the equation?

Answer 10

TAU <= Su

Question 11

Infinite clay slope, explain the process of getting FoS

Answer 11

Create force triangle (with angle) for good measure.
Find Fd and Fr
FoS = Fr/Fd

Question 12

Infinite clay slope, how to find critical depth?

Answer 12

Find Fr, Fd, FoS = 1 so the equation is:

H = (Su * L)/(GAMMA * b * sin(BETA))

Question 13

Find Fd for clay infinite slope

Answer 13

Fd = W * sin(BETA) = GAMMA * b * h * sin(BETA)

Question 14

Find Fr for an infinite clay slope

Answer 14

S = Su * L = (Su * b)/cos(BETA)

Question 15

For an infinite sand slope, what is the equation?

Answer 15

TAU <= SIGMA * tan(PHI)

PHI being the friction angle

Question 16

How do you find Fd for an infinite sand slope?

Answer 16

Fd = W * sin(BETA) = Gamma * b * h * sin(BETA)

It is the same as for clay

Question 17

For a finite cohesive slope, how do you determine the critical depth?

Answer 17

Same as before, Find Fd and Fr. However when equating them, the angle of THETA is 45 degrees

Question 18

What are the four types of slope failure?

Answer 18

Translational, Wedge, Rotational, and Compound.

TWRC! TWERK!

Question 19

How to find the FoS for a cohesive material in a rotational failure

Answer 19

Find Md = W * x (x is centroid to middle)
Mr = TAU * L * r (L is arc length = r * PI/180 * angle)
TAU = Su

FoS = Mr/Md

Question 20

How to find W in when figuring out Md for a cohesive rotational failure?

Answer 20

W = P * g * A

Question 21

Do card on slice method from coursework

Answer 21

Now bitch