Table of Contents
What is a toppling failure?
Toppling failure is a common mode of instability in layered and blocky rock slopes where rock blocks rotate about their toes and overturn. In this failure, rock blocks at the toe of the slope are overturned by the pressure of sliding mass from the upper part of the slope.
What are different types of slope failures?
Types of slope failure in geotechnical engineering
- Rotational failure. When rotational failure occurs, the failed surface will begin to move outwards and downwards.
- Translational failure.
- Compound failure.
- Wedge failure.
What is flexural toppling failure?
In flexural toppling failure, rock columns slide on one another and then fail due to bending individually (Goodman and Bray 1976). If this sliding is appropriately prevented, the failure of rock columns will be controlled.
What is rock toppling?
Topple failures involve the forward rotation and movement of a mass of rock, earth or debris out of a slope. This kind of slope failure generally occurs around an axis (or point) at or near the base of the block of rock. A good example of a site experiencing topple failures is Aldbrough, UK.
What are the condition of plane failure?
The plane failure occurs when a structural discontinuity plane such as; bedding plane, fault plane or preferred orientations of a joint set dips or daylight towards the valley or excavation at an angle smaller than the slope angle and greater than the angle of friction of the discontinuity surface.
What is wedge failure?
Wedge failure occurs due to sliding along a combination of discontinuities. The. conditions for sliding require that φ is overcome, and that the intersection of the discontinuities “daylights” on the slope surface.
What is direct toppling?
Direct Toppling can be an issue when you have near vertical intersections dipping into the slope and near horizontal base planes which undercut the blocks and form release planes. We will describe them with respect to the three zones labelled in the figure below.
What is the difference between a topple and a flow?
Types of mass movement A fall or topple happens when rocks and other sediments fall through the air and land at the bottom of a slope. Flows are a mixture of water, rock and sediment. A slide happens when a section of soil or rock suddenly gives way and moves down a slope.
What is soil slope?
The slope of the soil is an important soil property to consider when building or planting. The slope gradient is the angle of incline or decline, expressed in the percent of rise or fall of the soil surface from horizontal over a distance of 100 feet. Soil slope affects the flow of water that can erode the soil.
Can a slope toppling failure produce high velocities?
Such failures prove to be widespread in many ditterent kinds of rock masses. Slope toppling does not usually produce high velocities, like some rock glides, but, if uncontrolled, retrogressive fail ure can encompass a large volume of rockr with deep tension cracks, and considerable rock breakage .
What causes the slope of a slope to fail?
The important factors that cause instability in a slope and lead to failure are: Gravitational force. Force due to seepage water. Erosion of the surface of slopes due to flowing water. The sudden lowering of water adjacent to a slope.
Where does the toppling of a slope occur?
Toppling movement occurs in slopes where a regularly spaced set of joints or bedding planes strike parallel, or nearly parallel, to the slope face and dip at a steep angle into the face. This geological structure forms a series of tall, narrow slabs (Figure 1).
What causes a column of rock to topple on a slope?
Here the column of rock rotates about a fixed point at the base of the slope. This toppling action is due to the column’s center of gravity lying outside the base dimensions.