Exam - Citations And Graph Ideas

Question 1

What is the total number of fatal landslide events recorded between 2004 and 2016?

Answer 1

4862 fatal landslide events

This data is sourced from Froude & Petley, 2018.

Question 2

What are the types of movement classified by Hungr et al 2014?

Answer 2

Fall
Topple
Slide
Spread
Flow
Slope deformation

Question 3

What is an example of a complex landslide/ its impacts?

Answer 3

Mt Evans Rock Avalanche (Jan 2013) - flooding, close of SH6 (motorway), loss of fibre optic communications

Question 4

What are the factors for why a slope could reactivate or initiate with effect in graph?

Answer 4

1. Reduced cohesion (take off cohesive factor)
2. Reduce friction (lessen gradient of line)
3. Reduced effective stress (line to the left closer to 0)
4. Increase shear stress (upwards movement arrow)

Question 5

What are the internal causes if instability from Moore et al 2006?

Answer 5

Materials
Weathering
Pore water pressure

Question 6

What are the external causes of slope failure Moore et al 2006?

Answer 6

Removal of slope support
Increased loading
Transient effects

Question 7

What are internal causes of soil strength loss?

Answer 7

Soils subject to strength loss on contact with water or as a result of stress relief (strain softening).

Includes fine grained soils which are subject to strength loss or gain due to weathering, and soils with discontinuities characterised by low shear strength such as bedding planes, faults, joints etc.

Question 8

What is weathering in the context of soil?

Answer 8

Physical and chemical weathering of soils causing loss of strength (apparent cohesion and friction).

Includes slope ripening and soil weakening processes (e.g. loss of vegetation, shrink and swell, desiccation and surface cracking).

Question 9

How does pore-water pressure affect soil strength?

Answer 9

Elevated pore-water pressures causing a reduction in effective shear stress, most severe during wet periods or intense rainstorms.

Question 10

What are the ways of removal of slope support?

Answer 10

Undercutting by water (waves and stream incision), washing out of soil (groundwater flows), and human intervention (e.g. cutting, excavations, tunnelling and mining).

Question 11

What contributes to increased loading on soil?

Answer 11

Natural accumulations of water, snow, talus, and human intervention (e.g. fill, tips, buildings).

Question 12

What are transient effects that can impact soil stability?

Answer 12

Earthquakes and tremors, shocks and vibrations.

Question 13

X

Answer 13

X

Question 14

What causes grain crushing in debris flow slides?

Answer 14

Rapid sliding along the shear zone.

(Okada et al., 2000; Sassa et al., 1996)

Question 15

x

Answer 15

x

Question 16

What initiates creep in soil mechanics?

Answer 16

Increasing pore pressure leading to slow to rapid displacement.

Question 17

What is liquefaction?

Answer 17

A process where saturated soil substantially loses strength and stiffness due to applied stress, often leading to flow.

Question 18

What is the role of groundwater in debris flow slides?

Answer 18

Groundwater path contributes to pore water pressure changes affecting stability.

Question 19

What is the formula for bulk density?

Answer 19

Mass of soil/total volume (kg/m3 or g/cm3)

Question 20

What is the formula for bulk unit weight?

Answer 20

Bulk density * gravity

Question 21

What is the void ratio?

Answer 21

Volume of voids/ volume of solids

Question 22

What is the degree of saturation formula?

Answer 22

Volume of water/ volume of pores

Question 23

What is the equation for specific gravity?

Answer 23

Soul density/ water density

Question 24

What is the formula for porosity?

Answer 24

(Volume of voids/ total volume)x 100

Question 25

What is the formula for porosity?

Answer 25

Volume of voids/ total volume

Question 26

How do gonzalez and ferrer 2011 describe drained and undrained?

Answer 26

Drained - voids filled with water and air and fully water
Undrained - voids filled only with water
Physical properties depends on packing and if drained or undrained (if pore fluid can move rapidly under load)

Question 27

What are the equations for total stress at depth, at depth under water and in multilayer soil?

Answer 27

1. Sigma v = y x z (z depth, y unit weight)
2. Sigma v = above + yw x zw (unit soil and water)
3. “ = y1d1 + y2d2 + y3(z-d1-d2)

Question 28

What did Morgenstern 1995 write on?

Answer 28

Fundamental concepts of the limit equilibrium method for slope stability analysis e.g., slip mechanism results in slope failure

Question 29

What would a graph for confining pressure and normal/ shear stress be like? Hudson and Harrison 93

Answer 29

Increasing confining pressures increases peak and reduces/ removes drop to residual

Question 30

What do graphs look lien for different levels of rock strength?

Answer 30

Very good rock steep increase and vertical big drop to critical medium lesser increase and half drop least curved low increase and no drop

Question 31

How do you work out pore water pressure?

Answer 31

Water unit weight x height

Question 32

How do you get zw for fs calculations?

Answer 32

Assume worst case so full tension crack so = z

Question 33

What papers talk about the effect of temp and size in rock strength?

Answer 33

Jaeger et al 07 for temp (high temp lower peak)
Read and Stacey 09 for size (large less strong)

Question 34

What did potyondy and cundall 04 show with rock failure?

Answer 34

Failure the result of micro-fractures forming and coalescing

Question 35

What is importantly to remember with hoek-brown criteria for intact rock?

Answer 35

Empirical - chosen to fit data

Question 36

What is hoek-brown lacking in and what can aid it?

Answer 36

When minor principle stress becomes negative (tension) so griffths used

Question 37

What factors from Benedetta lecture can I add into essay?

Answer 37

Preconditions and preparatory factors (former being linked to susceptibility)

Question 38

What paper should I mention for talking about the type of slope failures?

Answer 38

Hungr et al 2014

Question 39

What could I put when talking about materials leading to slope failure?

Answer 39

Drained or undrained with their strength diagram (dilation or densification)

Question 40

What things should I add to answer which Jon mentioned?

Answer 40

Factor of safety (1 or below - byerless law)
Slope shear strength main resistor (friction and cohesion)
Drained undrained
Rain water generating pore pressure examples - rescuing effective more instability
Rapid pore pressure and liquefaction
Stress pathway diagrams

Question 41

What did gonzalex and ferrer produce a paper on in 2011?

Answer 41

Drained vs undrained

Question 42

Who put forward the idea of rock mass strength?

Answer 42

Hoek and brown 1997

Question 43

Who produced the geomechanics system?

Answer 43

Bieniawski 76 and 89

Question 44

How has the Hoek-brown failure criterion developed as of 2018?

Answer 44

Accounts for discontinuities

estimates the mechinical behaviour of rock masses

Question 45

What did carey et al 2019 produce a paper on?

Answer 45

The effect of pwp and Eqs on the movement rate of slow moving slides, it found that stong Eq acceleration resulted in rapid strain increases

Question 46

What is a source for liquefaction?

Answer 46

Bishop 1973 - Rapid loss of large proportion of the shear resistance due to the generation high pore water pressures