1. SLOPES GUILLERMO, MIRA ROELLA MANABAT, JAYZAM LLOYD VIERNES, ARAY

2. SLOPES - basically, it is a ground that has natural slant or incline, especially downward or upward

3. Classifications of Slopes NATURAL SLOPES
Classifications of Slopes NATURAL SLOPES -slopes that have been stable for many years may suddenly fail because o f changes in thopograp hy, seismicitism city, groundwater flows, loss of strength, stress changes, and weathering

4. Classifications of Slopes ARTIFICIAL SLOPES -it is also known as the “ Engineered-Slopes” - may be considered in three main categories: embankments, cut slopes, and retaining walls. As these slopes are man-made less uncertainty exists about their stability.

5. MODES OF FAILURES: -Slope failure occurs when the downward movements of material due to gravity and shear stresses exceeds the shear strength.

6. MODES OF FAILURES: - Slope failures are usually due either to a sudden or gradual loss of strength by the soil or to a change in geometric conditions, for example, steepening of an existing slope.

7. TYPICAL SLIDES THAT CAN BE EXPECTED TO OCCUR IN SOIL SLOPES: (1) FALLS
TYPICAL SLIDES THAT CAN BE EXPECTED TO OCCUR IN SOIL SLOPES: (1) FALLS -This is generally characterized by a rapid to extremely rapid rate of movement with the descent of material characterized by a freefall period. Falls are commonly triggered by earthquakes or erosion processes.

9. (2) TOPPLE -This is characterized by the tilting of rock without collapse, or by the forward rotation of rocks about a pivot point. Topples have a rapid rate of movement and failure is generally influenced by the fracture pattern in rock. Material descends by abrupt falling, sliding, bouncing and rolling.

11. (3)FLOW. -This is the most destructive and turbulent form of landslide
(3)FLOW -This is the most destructive and turbulent form of landslide. Flows have a high water content which causes the slope material to lose cohesion, turning it into a slurry. They are channelled by the landscape and move rapidly.

13. (4) SLIDES -This is one of the most common forms of failure and can be subdivided into translational and rotational slides.

14. (4.1) ROTATIONAL OR SLUMP -relatively slow movement of an essentially coherent block/s of soil, rock or soil-rock mixtures along some well-defined arch-shaped failure surface.

15. (4. 2) PLANAR OR TRANSLATIONAL
(4.2) PLANAR OR TRANSLATIONAL -slow to rapid movement of an essentially coherent block/s of soil, rock or soil-rock mixtures along some well-defined planar failure surface.

16. (4. 3) BLOCK SLIDE. - a single block moving along a planar surface. (4
(4.3) BLOCK SLIDE - a single block moving along a planar surface. (4.4) WEDGE SLIDE -block/s moving along intersecting planar surfaces.

17. (4.5) LATERAL SPREADING -a number of intact blocks moving as separate units with differing displacements (4.6) DEBRIS SLIDE - a soil-rock mixtures moving along a planar rock surface.

18. (4.7) CREEP -slow imperceptible downslope movement of soil or soil-rock mixtures.

20. (5) SPREAD -This phenomenon is characterized by the gradual lateral displacement of large volumes of distributed material over very gentle or flat terrain. -This process is triggered by rapid ground motion most commonly during earthquakes.

22. LANDSLIDE:. -is the movement of rock, debris or earth down a slope
LANDSLIDE: -is the movement of rock, debris or earth down a slope. -also known as landslips, slumps or slope failure.

23. The movement of landslide material can vary from abrupt collapses to slow gradual slides and at rates which range from almost undetectable to extremely rapid. Sudden and rapid events are the most dangerous because of a lack of warning and the speed at which material can travel down the slope as well as the force of its resulting impact.

24. TYPES OF SOIL FAILURES: (1)GENERAL SHEAR FAILURE
TYPES OF SOIL FAILURES: (1)GENERAL SHEAR FAILURE -characterized by well defined failure pattern, consisting of a wedge and slip surface and bulging (heaving) of soil surface adjacent to the footing Sudden collapse occurs, accompanied by tilting of the footing

25. (2)LOCAL SHEAR FAILURE - failure pattern consists of wedge and slip surface but is well defined only under the footing. Slight bulging of soil surface occurs. Tilting of footing is not expected.

26. (3)PUNCHING SHEAR FAILURE. -Failure pattern is not well defined
(3)PUNCHING SHEAR FAILURE -Failure pattern is not well defined. No bulging of ground surface and no tilting of footing occurs. The yield surfaces are vertical planes immediately adjacent to the sides of the foundation

28. SLOPE STABILIZATION -”Stability” is determined by the balance of shear stress and shear strength. A previously stable slope may be initially affected by preparatory factors, making the slope conditionally unstable.

29. SLOPE STABILIZATION -the process of changing the physical property of the slope to strengthen and improve the durability.

30. FACTORS AFFECTING SLOPE STABILITY 1. Strength of soil and rock. 2
FACTORS AFFECTING SLOPE STABILITY 1.Strength of soil and rock. 2.Type of soil and stratification. 3.Discontinuities and planes of weakness. 4.Groundwater table and seepage through the slope. 5.External loading. 6.Geometry of the slope.

31. CAUSES OF SLOPE FAILURE
Erosion.
Rainfall.
Earthquakes.
Geological factors.
External loading.
Construction activities such as excavation of slopes and filling of slopes.
Rapid drawdown*.
Increment of pore water pressure.
The change in topography.

32. Advantages:
1. Stabilizes the soil.
2. Absorbs raindrop impact.
3. Reduces velocity of surface runoff.
4. Improves infiltration.
5. Prevents erosion.

33. Disadvantages:
Rock slope protection can be considered unattractive.
2. Availability of mulch material within or near the Lake Tahoe Basin may be limited.

34. SLOPE STABILIZATION TECHNIQUES: 1. Rock Slope Protection 2
SLOPE STABILIZATION TECHNIQUES: 1. Rock Slope Protection 2. Slope Roughening, Terracing, and Rounding 3. Mulches (pine needle, wood, hydro) 4. Erosion Control Blankets/Mats

35. ROCK SLOPE PROTECTION -a layer of loose rock or aggregate placed over an erodible soil surface -rock slope protection is best suited in areas where revegetation is difficult, and is often used on steep slopes above retaining walls. Rock slope protection should be implemented only when hydrologic conditions prohibit alternative stabilization.

37. SLOPE ROUGHENING, TERRACING, AND ROUNDING
SLOPE ROUGHENING, TERRACING, AND ROUNDING -Slope shaping is well suited for large cut and fill slopes, especially those associated with highway construction.

39. MULCHES -Mulch should be applied where soil has been disturbed and vegetation has been removed. Hydromulch is only recommended for steep, inaccessible areas.

40. EROSION CONTROL MATS/BLANKETS -are cost effective methods for stabilizing disturbed soil on steep slopes and graded construction sites. They can also be used to stabilize constructed channel ways. Consult the manufacturer for appropriate application of a specific product.