Basic concepts of Engineering geology from various books and internet images, which will be helpfull to many civil, petroleum and mining engineering students at basic level.
2. ADITYA
Unit-3 Outcomes
At the end of the Course, Student will be able to:
CO 1 : Understand the origin, occurrence and
distribution of groundwater.
CO 2 : Understand the causes of earthquakes.
CO 3 : Understand the causes of landslides.
CO 4 : Understand importance of groundwater,
earthquakes and landslides.
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Contents
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
Ground Water
Water table, Cone of depression, Geological controls of Ground Water
Movement and types of aquifers, Ground Water Exploration Techniques.
Earthquakes
Terminology, Classification, causes and effects, Shield areas and Seismic
bells, Richter scale intensity, Precautions of building constructions in
seismic areas.
Land Slides
Classification of Landslides, Causes and Effects, measures to be taken to
prevent their occurrence at Landslides
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
Module 1 : Introduction to Groundwater and its
hydrology
Module 1 : Introduction to Groundwater and its
hydrology
6. ADITYA
Learning Outcomes
At the end of this lecture, Student will be able to:
LO 1 : Understand the origin and occurrence of
groundwater.
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
7. ADITYA
Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Hydrology is the study of the distribution and movement of water both on and below
the Earth's surface, as well as the impact of human activity on water availability and
conditions.
Groundwater, water that occurs below the surface of Earth, where it occupies all or part
of the void spaces in soils or geologic strata. Anyhow both surface and subsurface water
are related through the hydrologic cycle (the continuous circulation of water in the
Earth-atmosphere system).
Study of groundwater is more relevant for civil engineers as it concerns in the following
ways:
1. Groundwater as endogenic geological agent in weathering and erosion.
2. Groundwater influences the slip produced in fault in subsurface strata.
3. It is one of major reasons for the occurrence of landslides and rock fall.
4. And it is the major source of life, construction, agriculture and industries.
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Water Table the level below which
the ground is saturated with water.
Water bearing properties of rocks
1. Aquifers as both porosity and
permeability
2. Aquitards as porosity with limited
permeability
3. Aquicludes as porosity and no
permeability
4. Aquifuges as neither porosity not
permeability.
Types of Aquifers
1. Confined
2. Unconfined
3. leaky
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Types of groundwater
Zone of aeration Zone of saturation
Soil water Unconfined or free groundwater
Pellicular water ( percolating water
stick to voids )
Confined water
Vadose water (gravity water) Fixed groundwater( not influenced by
gravity)
Perched water (water in clay
formations)
Connate water (origin of rock)
Capillary water Internal water (very deep in the
interior of the earth)
Juvenile water (Magmatic water)
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Geological controls of Ground Water Movement
Groundwater movement in the zone of aeration is not much influenced by gravity and
topographic factors, while in zone of saturation the influencing factors are of geological
concern.
They are:
1. Permeability of rocks.
2. Presence of fractures.
3. Attitude of bedding of the formations.
4. Buried river channels.
5. Presences of impermeable formations like dolerite dykes and sills, salt plugs.
6. Difference in water table levels between each cone of depression and as well as
between various geological formations based on type of material ( clayey formations
and confined formations).
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Ground Water Exploration Techniques
The purpose of exploration is to detect the indirect indicators (subsurface aquifer formations) and
locate the potential zones for exploitation (extraction of groundwater). The main geophysical
methods which are useful in solving some of the problems of hydrogeology, are the Electrical, Seismic,
Gravity, and Magnetic methods.
There are two wats of conducting the investigation of an area; preliminary and final investigations.
There are three kinds of geophysical investigation of groundwater
They are:
Geological investigations:
1. Study of rock types
2. Study of topography
3. Study of weathering
4. Study of geological structures
5. Study of intrusive rocks
6. Geological mapping of the area after field study (marking of identified formations)
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Hydrological investigations
1. Study of water table
2. Study of surface water bodies
3. Study of springs and seepages
4. Quality of water
5. Study of rainfall and climate
6. Pump tests
Geophysical Investigations
The geological and hydrological investigations will give only limited amount of information, while
the remain information is forbidden due to soil cover, vegetation etc.,.
Geophysical investigations are much more reliable in such cases as the methods can be applied
both on surface and subsurface of the crust.
The most commonly used geophysical method is electrical resistivity method as it give information
in the form of profiling and sounding of the formations.
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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Effects of excess of use of groundwater or
over tapping
1. Excavation of open wells or drilling
of bore wells near to each other can
effect in drastic decrease the yield of
groundwater.
2. Saline water intrusion.
3. Water scarcity
4. When groundwater is overused, the
lakes, streams, and rivers connected
to groundwater can also have their
supply diminished.
5. Land subsidence occurs when there is
a loss of support below ground.
Water Logging
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE
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After completion of module 1 the student is now able to understand the
origin, occurrence and distribution of groundwater.
Summary
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Summary
From this unit – 2 students are now able illustrate and
understand the occurrence of minerals and rocks,
their identification.
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Engineering Geology
P Shiva Kumar, Sr. Assistant Professor, CE