Slope Stability

Which mode of slope failure is characterized by the detachment of soil and/or rock fragments that fall down a slope?

The factor of safety for a slope is generally defined as the ratio of what two parameters?

For an infinite slope in granular soil (c' = 0) with a friction angle of 30 degrees, what is the factor of safety if the slope angle β is 20 degrees?

What is the critical height (Hcr) for an infinite slope with c' = 400 lb/ft^2, γ = 115 lb/ft^3, β = 50 degrees, and φ' = 25 degrees?

In the analysis of finite slopes with plane failure surfaces using Culmann's method, what is the critical angle of the failure plane, θcr, for a slope with an angle β and a developed friction angle φ'd?

A cut slope is to be made in a soil having γ = 105 lb/ft^3, c' = 600 lb/ft^2, and φ' = 15 degrees. The slope angle is 45 degrees. If a factor of safety of 3 is required, what is the developed friction angle, φ'd?

When a slope failure surface passes at some distance below the toe of the slope, what is this mode of failure called?

For a slope in a homogeneous clay soil with φ = 0, what is the critical height (Hcr) if the undrained cohesion cu = 40 kN/m^2, the unit weight γ = 17.5 kN/m^3, and the stability number m = 0.195?

What is the term for the dimensionless parameter 'D' used in the stability analysis of clay slopes (φ = 0) when the slope angle is less than 53 degrees?

A cut slope was excavated in a saturated clay at a 40-degree angle. Failure occurred when the cut reached 6.1 m. A rock layer was located 9.15 m below the ground surface. What is the value of the depth function, D?

For a saturated clay slope (φ = 0) with a slope angle β = 40 degrees, a depth function D = 1.5, a unit weight γ = 17.29 kN/m^3, and a critical height Hcr = 6.1 m, what is the undrained cohesion, cu, of the clay?

In the stability analysis of a saturated clay slope with earthquake forces, the moment of the driving forces is given by Md = W*l1 + kh*W*l2. What does the term kh represent?

A cut slope in saturated clay has an angle of 56 degrees. Assuming a horizontal seismic coefficient kh = 0.25, what is the stability factor M based on Koppula's analysis for β >= 55 degrees?

For a slope in a homogeneous c'-φ' soil, the factor of safety is determined using Taylor's stability number, m. What is this stability number a function of?

A slope with an angle β = 45 degrees is to be constructed with a soil that has φ' = 20 degrees. Using Taylor's stability number chart, what is the value of the stability number, m?

A slope has a height of 10 m, γ = 18.9 kN/m^3, c' = 24 kN/m^2, and β = 45 degrees. If the developed friction angle is assumed to be 15 degrees, what is the required developed cohesion, c'd, based on Taylor's stability chart?

Using Michalowski's solution for a slope with β = 45 degrees, c'/(γH tan φ') = 0.349, and φ' = 20 degrees, what is the resulting factor of safety, Fs?

In the Ordinary Method of Slices, what is the primary assumption made regarding the forces acting on the sides of each slice?

Which method of slices is considered more refined than the Ordinary Method because it accounts for the effect of forces on the sides of each slice to some degree?

In Bishop's Simplified Method of Slices, the term mα(n) is used in the factor of safety equation. What is this term a function of?

For stability analysis with steady-state seepage, Bishop and Morgenstern developed tables for stability coefficients m' and n'. The factor of safety is calculated as Fs = m' - n'*ru. What does ru represent?

A slope has a 2H:1V configuration, which corresponds to β = 26.57 degrees. Given φ' = 25 degrees, c'/γH = 0.05, and D = 1.00. Using the stability coefficients from Table 15.3b, what is the value of m'?

Using the data from Example 15.9, for a 2H:1V slope with φ' = 25 degrees, c'/γH = 0.05, and ru = 0.25, what is the factor of safety, Fs, when the depth function D = 1.00?

Spencer's solution for slope stability is an advancement over Bishop's simplified method because it satisfies equilibrium with respect to what?

Using Spencer's solution charts for a slope with ru = 0.25, β = 26.57 degrees, and an assumed Fs = 1.2, what is the required developed friction angle, φ'd, if c' = 20 kN/m^2, γ = 18.5 kN/m^3, and H = 21.62 m?

In the case history of the I-95 test embankment failure, what was the approximate factor of safety for the actual surface of sliding as obtained by using Bishop's simplified method with vane shear test data?

What key conclusion was drawn from the I-95 embankment case history regarding the predicted versus actual failure surface?

Morgenstern's method for analyzing rapid drawdown conditions assumes that the unit weight of saturated soil (γsat) is equal to what?

For a slope with tan(β) = 1/3, a friction angle φ' = 30 degrees, and c'/γH = 0.025, what is the factor of safety, Fs, for a rapid drawdown where L/H = 0.6?

What is the primary reason for the initial decrease in the factor of safety during the construction of a clay embankment on saturated soft clay?

For a cut slope in saturated soft clay, why does the factor of safety decrease over time after excavation is complete?

An infinite slope has a steady-state seepage with the groundwater table at the ground surface. Given c' = 10 kN/m^2, φ' = 20 degrees, β = 15 degrees, H = 6 m, and γsat = 17.8 kN/m^3. The effective unit weight γ' is 7.99 kN/m^3. What is the factor of safety?

A factor of safety of 1.5 for a slope is generally considered to be:

Which analysis method for finite slopes approximates the potential failure surface as a plane?

In the mass procedure for a homogeneous clay slope with φ = 0, for a slope angle β greater than 53 degrees, the critical circle is always what type of circle?

For a homogeneous c'-φ' slope with a 1V:2.5H profile, γ = 18 kN/m^3, c' = 12 kN/m^2, φ' = 20 degrees, and H = 10 m, what is the factor of safety, Fs, according to Singh's charts?

What type of failure surface is assumed in the stability analysis by Michalowski (2002), which uses the kinematic approach of limit analysis?

Using Michalowski's analysis charts (Figure 15.27), what is the critical height of a slope with β = 45 degrees, c' = 24 kN/m^2, φ' = 20 degrees, and γ = 18.9 kN/m^3?

In the Ordinary Method of Slices, the factor of safety Fs is calculated based on the equilibrium of moments of which two forces about the center of the trial circle?

Why is Bishop's simplified method of slices generally preferred over the ordinary method of slices in modern practice?

What is the primary difference in the failure surface assumed by Morgenstern's drawdown analysis compared to Michalowski's general slope analysis?

An infinite slope in a c'-φ' soil without seepage has reached critical equilibrium (Fs = 1). If the slope angle β is 30 degrees and the soil friction angle φ' is 20 degrees, what is the value of the term γHcr/c'?

For a finite slope in a homogeneous c'-φ' soil, what is the stability number, m = c'/(γHcr), for a slope with an angle β = 30 degrees and a friction angle φ' = 20 degrees?

Using Michalowski's solution for a slope with steady-state seepage (ru=0.5), a slope angle β = 30 degrees, and a soil friction angle φ' = 30 degrees, what is the value of Fs/tan(φ')?

For a homogeneous clay slope (φ = 0) with a slope angle of 60 degrees, find the radius, r, of the critical toe circle if the critical height is 11.72 m.

For a slope in c'-φ' soil, the friction circle method is used. The friction circle is a circle to which the resultant force F is tangent. What is its radius?

When analyzing a slope in layered soils using the method of slices, how are the soil properties for each slice handled in the calculation?

In the analysis of an infinite slope with steady state seepage parallel to the slope, and the water table at the surface, which unit weight is used for the frictional resistance term?

What does a stability analysis factor of safety of 1.0 signify?

For the stability analysis of a rapid drawdown condition in an embankment, what does L/H represent in Morgenstern's charts?