KEY OF MODERN DEVELOPMENT

Dr . VINAY KUMAR PANDEY, Ph.D., M.Sc. (Geology), M. Sc. (Disaster Mitigation)

Dept Of Geology, Lucknow University, Lucknow, India.

E-mail: vinay78pandey@gmail.com

TOWER OF PISA, ITALY

ROAD DAMAGE DUE TO SHINKAGE OF SUBSOIL

ROAD DAMAGER DUE TO SMALL RAIN

SMALL BRIDGE WASH OUT DUE TO LACK OF PROTECTION WORK

LOOSE SOIL

ROAD CONSTRUCTED ON SLOPE WASH MATERIAL WITH UNPROPER PROTECTION

EFFECT OF FLOOD

LOSS DUE TO LACK OF SAFETY AWERNACE

SLIDE DUE TO FLOOD

DANGER ZONE

WHY THIS HAPPENED SOLUTION

POOR SUBSURFACE

CONDITION

LACK OF SAFTY MEASURES

LACK OF AWERNASE

STRUCTURE

CONSTRUCTED WITHOUT

PROPER STUDY OF

DEFORMABILTY.

STUDY OF AREA IN VIEW OF

SOIL-SUBSOIL NATURE FOR

CONSTRUCTION, SAFETY

AND REMEADY MEASURES

INCLUDING ECONOMICAL

VALUE BEFORE FINALIZE

THE PROJECT.

FOR STUDY THE NATURE OF

SOIL-SUBSOIL AND ITS

CONSTRUCTION

PROPERTIES COMES UNDER

ENGINEERING GEOLOGY

SOIL BEARING CAPACITY FAILED

ENGINEERING GEOLOGYEngineering 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 Engineering Geology.

HISTORY OF ENGINEERING GEOLOGYThe first book entitled Engineering Geology was published

in 1880 by William Penning.

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 engineering projects.

IMPORTANCE OF ENGINEERING GEOLOGY IN DEVELOPMENT

• To recognise potential difficult ground conditions prior to

detailed design and construction

• It helps to identify areas susceptible to failure due to

geological hazards

• 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 Geological Hazard

Geotechnical

Material Properties

Landslide & Slope stability

Erosion

Flooding

Dewatering

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 development.

1lb (Pound) = 0.454 kg

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BASIC METHODS USED BY ENGINEERING GEOLOGIST

Geological field mapping of geological structures, formations, soil

units and hazards.

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.

Geophysical survey.

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

Cavity

Filling material

Dewatering/ ground water inflow

Direction and amount of Dip and strike

EFFECT OF DISCONTINUTY STRIKE & DIP ORIENTATION IN EXPLORATION/TUNNELING

STRIKE PERPENDICULAR TO TUNNEL AXIS

STRIKE PARALLEL TO TUNNEL AXIS

Drive with dip: Dip 45-90°

Drive with dip: Dip 20-45°

Dip 45-90° Dip 20-45°

Very favorable Favorable Very favorable Fair

Drive against dip: Dip 45-90°

Drive against dip: Dip 20-45°

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 unjointed).

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.

SURFACE/SUBSURFACE INVESTIGATION

INVESTIGATIONS

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 etc.

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 remedies measures.

RESULTS

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 cables etc.