Research Paper(Term Paper)

1. .........Slope stability.........
Prepared By:Name :- Riyaz Ahmad Bhat;
Email Id: (bhatriyaz1@gmail.com)
Department of civil engineering and technology
Course:- B.Tech. , Section :- C;
System Id : (2012018157);
Roll No.:- (120107192);
Submitted to: Professor, Mr. Gaurav Goel.

2. 1.Abstract
 Despite of our improvement in recognition ,
prediction and mitigative measures, Landslides
still have social, economic and environmental
toll in mountainous regions. This is partly due to
the complexity of the processes driving slopes
failures and our inadequate knowledge of the
underlying mechanisms. Ever increasingly,
Experts are called upon to analyze and predict
the stability of the given slope , assessing its risk,
potential failure mechanisms, and velocities ,
areas endangered, and possible remedial
measures.

3. Slope Stability analysis and the
purpose
 These Notes includes the field of Slope Stabilty
analysis and the purpose such analysis serve in
investigation of potential slope failure mechanism.
Advancements in and the evolution in computer based
analysis techniques are discussed, first with respect to
commonly applied conventional methods .The
determination of kinematics for several common
modes of failure are presented in addition to the
corresponding analytical and limit equilibrium for
factors against slope failure.

4. ….continued
 The main objective of the slope stability Analysis has
been discussed here.
 Slope stability analysis before the computer age and now in
the computer era has been discussed in detail. There are
various softwares/ programmes used for slope stability
purpose. Concept of Hybrid coupled modeling is being also
included.
 Numerical modeling methods and their application to rock
slope stability analysis has been introduced briefly. Yet it
must be emphasized that numerical is a tool and not a
substitute for critical thinking and judgment. As such,
numerical modeling is most effective when by an
experienced and cautious user.

5. 2).Introduction:
 A slope may be an unsupported or supported, inclined surface
of some mass like soil mass. Slopes can be natural or man made.
These may be above ground level as embankments or below
ground level as cuttings. SLOPE STABILITY In
naturally occurring slopes like along hill slopes and river sides,
the forces of gravity tends to move soil from high levels to low
levels and the forces that resist this action are on account of the
shear strength of the soil.
Presence of water increases weight and reduces shear strength
and hence decreases stability.
Weights of man made structures constructed on or near slopes
tend to increase the destabilizing forces and slope instability.

6. Causes of failure of Slopes:
 The important factors that cause instability in slope
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and lead to failure are
1. Gravitational force.
2. Force due to seepage of water.
3. Erosion of the surface of slope due to flowing water.
4. The sudden lowering of water adjacent to the slope.
5. Forces due to earthquakes.

7. 3)
Explanation
 Slope Stability Analysis

Slope stability analysis is performed to assess the
safe design of a human-made or natural slopes (e.g.
embankments, road cuts, open-pit mining,
excavations, landfills etc.) and the equilibrium
conditions.
 Definition: The term
slope stability may be
defined as the resistance of inclined surface to failure
by sliding or collapsing

8. The main objectives of slope
stability analysis
 The main objectives of slope stability analysis are
finding endangered areas, investigation of potential
failure mechanisms, determination of the slope
sensitivity to different triggering mechanisms,
designing of optimal slopes with regard to safety,
reliability and economics, designing possible remedial
measures, e.g. barriers and stabilization.

9. continued….
 Successful design of the slope requires geological
information and site characteristics, e.g. properties of
soil/rock mass, slope geometry, groundwater
conditions, alternation of materials by faulting, joint
or discontinuity systems, movements and tension in
joints, earthquake activity etc. Choice of correct
analysis technique depends on both site conditions
and the potential mode of failure, with careful
consideration being given to the varying strengths,
weaknesses and limitations inherent in each
methodology.

10. Before the computer age
 stability analysis was performed graphically or using
hand-held calculator.
 Today engineers have a lot of possibilities to use
analysis software, ranges from simple limit
equilibrium techniques through computational limit
analysis approaches (e.g. Finite element limit analysis,
Discontinuity layout optimization) to complex and
sophisticated numerical solutions (finite-/distinctelement codes).

11. continued….
 The engineer must fully understand limitations of each
technique. For example, limit equilibrium is most
commonly used and simple solution method, but it can
become inadequate if the slope fails by complex
mechanisms (e.g. internal deformation and brittle fracture,
progressive creep, liquefaction of weaker soil layers, etc.).
In these cases more sophisticated numerical modelling
techniques should be utilised. In addition, the use of the
risk assessment concept is increasing today. Risk
assessment is concerned with both the consequence of
slope failure and the probability of failure (both require an
understanding of the failure mechanism).

12. continued….
 Within the last decade (2003) Slope
Stability Radar has been developed to
remotely scan a rock slope to monitor
the spatial deformation of the face.
Small movements of a rough wall can
be detected with sub-millimeter
accuracy by using inter-ferometry
techniques

13. Conventional methods of analysis:
 Most of the slope stability analysis computer
programs are based on the limit equilibrium
concept for a two- or three-dimensional
model. In rock slope stability analysis
conventional methods can be divided into
three groups: kinematic analysis, limit
equilibrium and rock fall simulators.

14. Numerical methods of analysis
 Numerical modelling techniques provide an approximate
solution to problems which otherwise cannot be solved by
conventional methods, e.g. complex geometry, material
anisotropy, non-linear behaviour, in situ stresses. Numerical
analysis allows for material deformation and failure,
modelling of pore pressures, creep deformation, dynamic
loading, assessing effects of parameter variations etc.
However, numerical modelling is restricted by some
limitations. For example, input parameters are not usually
measured and availability of these data is generally poor.
Analysis must be executed by well trained user with good
modelling practise. User also should be aware of boundary
effects, meshing errors, hardware memory and time
restrictions. Numerical methods used for slope stability
analysis can be divided into three main groups: continuum,
discontinuum and hybrid modelling.

15. • Hybrid/coupled modelling
 Hybrid codes involve the coupling of various
methodologies to maximize their key advantages, e.g.
limit equilibrium analysis combined with finite
element groundwater flow and stress analysis adopted
in the SVOFFICE or GEO-STUDIO suites of software;
coupled particle flow and finite-difference analyses
used in PF3D and FLAC3D. Hybrid techniques allows
investigation of piping slope failures and the
influence of high groundwater pressures on the
failure of weak rock slope. Coupled finite-/distinctelement codes, e.g. ELFEN, provide for the modelling
of both intact rock behaviour and the development
and behaviour of fractures.

16. >> Work Done <<
:-
 Watched Videos and Images:
During the study of paper, I watched
Almost all related Videos and Images which
helped me in understanding the main Objective
Of studying Stabilty of Slope analysis. These
videos helped me to know the work done on slope
stabilty and future plannings done, and helped me
to go further steps.

17. Visited to Kashmir mountain
slopes
 The slopes of western Lesser Himalaya (at Sangaldhan
Block of Udhampur near Ramban, Jammu and
Kashmir India) are being severely affected by tectonic
and erosional activities. These activities result in
deposit of a thick cover of rock fragments and
overburden just above the hard rock. The thickness of
overburden cover has directly affected the stability of
slope in the study area, though the traditional stability
estimation techniques, rock mass rating and slope
mass rating, rate this area as moderately stable which
does not represent the real stability condition.

18. quake on 08th october 2005 of
Muzaffar-abad Kashmir
 The Mw=7.6 Kashmir Earthquake occurred on 8th
October 2005 as a result of rupture on the NW-SE
orientated Muzaffar-abad fault. The hypocenter was
located at a depth of about 20 km about 19 km NE of
Muzaffarabad in the Neelum River valley. The fault
rupture extends for a total distance of about 200 km.
The earthquake resulted in widespread destruction
over 28,000 km2. The official death toll is 87,300, with
landslides being responsible for about 20,000 fatalities
.

19. 6) CONCLUSION
 At the conclusion of this paper we are able to
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conclude following objectives:
Understand the basic concept of slope stability
analysis;
Understand the basic design considerations;
Be familiar with slope stability analysis and design
procedure;
Know how to verify computer analyses and results;
Be able to perform simple slope stability analysis; and
Be able to present the analysis and results effectively.

20. Thanks