Slopes

B.

Material B is cohesive.

C.

I know this because the intercept, which determines the cohesion value, is much higher for material B than that of material A.

D.

The cohesion value of material B is 3948 pascals.

E.

Material A: Shear strength = (0.696*4000)+59= 2843 pascals

Material B: Shear strength = (0.714*4000)+3948 = 6804 pascals

F.

The data defines a linear relationship between shear strength and normal force.

The general formula for a linear expression is y=mx+b.

Material A: y = 0.696x + 59

Material B: y = 0.714x + 3948

G.

Friction angle of material A: S = 0.696x + 59

(S - 59)/x = 0.696

tan^-1 (S-59)/x = undefined

tan^-1 0.696 = 34.84°

H.

Friction angle of material B: S = 0.714x + 3948

(S - 3948)/x = 0.714

tan^-1 (S - 3948)/x = undefined

tan^-1 (0.714) = 35.53°

Dry density (rho): 1800kg/m^3

Wet density (rho): 2200kg/m^3

Gravity: 9.8m/s^-2

Phi angle: 30°

Slab thickness: 1 meter to 4 meters

Failure plane angle (alpha): 30°

Cohesion: 9800 pascals

Saturation depth: 1 meter to 4 meters

The results shown in these calculations are consistent with land use changes over time in the area. The Riverside Avenue landslide in October 2019 was predicted ahead of time due to factors such as slope instability and shifting of tree growth direction. Aerial photos of the area allow us to see these factors on a regional scale, and it shows a very small number of trees prior to the 2019 landslide. This would have led to a low amount of root cohesion in the soil, allowing a landslide to occur more easily.

In the calculations tested with these graphs, I found that a simultaneous increase in slab thickness and saturation depth played a significant role in the likelihood of landslides. As they both increased, the chance of a landslide increased as well.