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LOSS DUE TO LACK OF
SLIDE DUE TO
WHY THIS HAPPENED SOLUTION
STUDY OF AREA IN VIEW OF
SOIL-SUBSOIL NATURE FOR
CONDITION CONSTRUCTION, SAFETY AND
LACK OF SAFTY MEASURES INCLUDING ECONOMICAL
VALUE BEFORE FINALIZE THE
LACK OF AWERNASE
STRUCTURE CONSTRUCTED FOR STUDY THE NATURE OF
SOIL-SUBSOIL AND ITS
WITHOUT PROPER STUDY
OF DEFORMABILTY. COMES UNDER ENGINEERING
Engineering geology is the application of geology in design,
construction and performance of civil engineering works.
Engineering geological studies may be performed during the planning,
environmental impact analysis, civil or structural engineering design,
value engineering and construction phases of public and private works
projects, and during post-construction and forensic phases of projects.
Soil/Rock deformability pattern, stability are main concern of
HISTORY OF ENGINEERING GEOLOGY
The first book entitled Engineering Geology was published in 1880 by
The first American engineering geology text book was written in 1914
by Ries and Watson.
The need for geologist on engineering works gained world wide
attention in 1928 with the failure of the St. Francis dam in California
and the loss of 426 lives.
More engineering failures which occurred the following years also
prompted the requirement for engineering geologists to work on large
IMPORTANCE OF ENGINEERING GEOLOGY IN
• To recognise potential difficult ground conditions prior to detailed
design and construction
• It helps to identify areas susceptible to failure due to geological
• To establish design specifications
• To have best selection of site for engineering purposes
• To have best selection of engineering materials for construction
AREA COVERED BY ENGINEERING GEOLOGY
Landslide & Slope stability
Seismic Studies Etc.
Most important roles of the engineering geologist is the interpretation of
landforms and earth processes to identify potential geologic and related
man-made hazards that may impact civil structures and human
BASIC METHODS USED BY ENGINEERING
Geological field mapping of geological structures, formations, soil units and
Review of Geological literatures, maps, Geotechnical reports, engineering plans,
environmental reports, Arial photographic studies, remote sensing data,
topographical map etc.
The surface and subsurface investigations as the excavation, sampling and logging
of earth/rock materials in drilled borings, backhoe test pits and trenches, fault
trenching, and bulldozer pits, Geomechanical test, hydrological tests etc.
Deformation monitoring of soil (Plate load Test), Rock on surface & subsurface.
Recommendation for safety measures.
MAIN FACTORS AFFECTING THE ROCK QUALITY
Topography of area
Types Soil/rock on Surface as well as Subsurface.
Degree of weathering
Number of Joint sets
Spacing between joints
Dewatering/ ground water inflow
Direction and amount of Dip and strike
EFFECT OF DISCONTINUTY STRIKE & DIP
ORIENTATION IN EXPLORATION/TUNNELING
STRIKE PERPENDICULAR STRIKE PARALLEL TO TUNNEL AXIS
TO TUNNEL AXIS
Drive with dip: Dip Drive with dip: Dip 20- Dip 45-90° Dip 20-45°
Very favorable Favorable Very favorable Fair
Drive against dip: Dip Drive against dip: Dip Dip 0-20° , Irrespective of strike angle
Fair Unfavorable Fair
METHODS OF STUDY THE ROCK QUALITY
A number of Geotechnical parameters govern condition of Rock mass
and the nature of its discontinuities. Main two are:-
(1) RMR (2) Q SYSTEM
(1) RMR (Rock Mass rating):
Bieniawski (1973), proposed RMR system, also know as ‘Geomechanics
Classification” for jointed rock masses. Many modifications has undergone
time to time.
Five basic parameters considered for RMR: STRENGTH OF ROCK, RQD
(Rock Quality Designation), SPACING OF JOINTS, CONDITION OF JOINTS
& GROUND WATER CONDITION.
Final RMR value related to five classes of rock mass i.e. ‘very good’, ‘good’’,
‘fair’, ‘poor’, ‘very poor’ rock.
METHODS OF STUDY THE ROCK QUALITY
Q- SYSTEM (ROCK MASS QUALITY)
Proposed by Basedon in 1974, based on the study of 200 tunnel case histories.
The rock quality Q is determined by estimating six parameters. These are RQD,
JOINT SET NUMBER (Jn), JOINT ROUGHNESS NUMBER (Jr), JOINT
ALTERATION NUMBER (Ja) AND STRESS REDUCTION FACTOR (SRF).
Q= (RQD/Jn) x (Jr/Ja) X (Jw/SRF) (Barton et. al. 1974)
The numerical value Q ranges from 0.001 (for exceptionally poor quality squeezing
ground) to 1000 (for exceptionally good quality rock which is practically
Q-value is divided into 9 categories of rock quality which are related to support
requirement depending upon excavation span and intended use of excavation.
FIELD INVESTIGATIONS LABOURATURY INVESTIGATIONS
(A) Geotechnical (a) Physical properties of Soil & Rock
(B) Hydrological (b) Geomechanical Properties
(C) Geophysical (c ) Petrological studies of rock & soil
(D) Construction material
Main Field tests are Drilling, Pit excavation, Deformability test (Goodman Jack
Test & Hydro Fracture test), Load bearing capacity test (Plate Load Test), Water
Percolation test (permeability test), Earth resistivity test, Seismic reflection test
(know the subsurface fault/ shear zone), aggregate test , topographical studies
Studies of Satellite imageries is very useful to understand the topography,
geomorphology of area.
On the basis of RMR and Q Value, geologist suggest
supporting system in excavated rock/soil.
On the basis of geotechnical & geologist report
project designer has fixed the structure design and
CAREER IN ENGINEERING GEOLOGY
Infrastructure Projects as Hydro Power Plant,
Tunnels for railway/transport, Canal, Dam, reservoir,
highways, bridges, buildings, water treatment plant,
land use, environmental studies etc.
For Mine and Quarry excavations, mine reclamation.
For coastal engineering, sand replenishment, sea cliff
stability, water front development.
For offshore drilling platform, sub sea pipeline and