curs 1 - engleza

8/3/2019 Curs 1 - Engleza

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Engineering Geology

2 hours Course /2 weeks

2 hours Laboratory /2 weeks

Titular of course:

Senior lecturer Dr.Eng. geologist Anca- Andreea Balog


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Courses:

1. Introduction to Geology. The Earths interior.

2. Mineralogy notions.

3. Igneous, Metamorphic and Sedimentary Rocks andProcesses.

4. Geologic structures. Tectonic Forces, Folds, Fracturesin Rocks.

5. Earthquakes, Mass Wasting, Karstic Phenomena.

6. Ground water.

7. Geological research for buildings.


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Geotechnics -study the rocks as foundation ground, as regards to their

locations, giving the necessary data for designing and making the buildings,and as construction materials.

The foundation ground can consist of dense rocks or ofsoils (soft or weathered rocks)

geotechnic object of study geology object of study

The foundation ground is the zonelocated at the Earth s surface were, due

to the construction of the building,changes are taking place, given theprevious situation, and where the buildingactions effect is felt.

Introduction to Geology. The Earths interior.

Structure

Foundation

The foundationground


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The geology is the science which study the Earth as a whole: theorigin, the structure, the composition and history, as well as theprocesses and the phenomena involved in all these aspects.

In building it gives the dates concerning:-the geological structure-the tectonics of the region-the petrophysical characteristics of the rocks

-the possibility of their modification in time under the external factors(and of the buildings)-ensure the natural building stones

ENGINEERING GEOLOGY

The technical-geology research methods arebased on :-mineralogy, petrography, tectonics, hydrogeology,geophysic, geochemistry, vulcanology andearthquake-science elements,

next to dates given by other sciences: physics, chemistry, mathematics,

strength of materials


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GENERAL DATA ABOUT THE EARTH

The planets: Vulcano (small, between Mercury and Sun), Mercury, Venus, Mars, Jupiter,

Saturn, Uranus, Neptune, Pluton The Solar System

Pear shape The averagesurface of the seas and

oceans unaffected by thetides and their extension

under the continents

The surface = 510,10 mill.km2

The volume = 1083 mld.km3

The equatorial radius = 6378,14 kmThe polar radius = 6356,75 kmThe equatorial length = 40076,59 kmThe meridian length = 40009,15 km

2. The atmosphere of the Earth-nitrogen (N)- 78%; oxygen (O)- 21%; othergases (Argon, Hydrogen, Neon, Helium,Krypton, Xenon),water vapor, dust, smoke,industrial gas products which are corrosiveand attack buildin materials - 1%,

1. The Earths size and shape


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2. Earths motionsMovement of revolution around the Sun in 365 days and 6 hours

Consequences:

-The seasons (the axe inclination with 23027 from the elliptical plan -ofthe orbit)

Rotation around its axis -within 24 hoursConsequences:-the alternation between day and night

21 March (equinox)22 June (solstice)23 September (equinox)22 December (solstice)

(at a speed of 30 km/s)

The Sun


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3. Physical properties of the Earth

Geomagnetism orientated magnetic field due to the faster rotation ofthe nucleus comparing with the external layers

Gravity(9,81 m/s )2

Pressure due to the own weight (vertical)= geological pressure- orientated (horizontal) = Stress

Ex. Orogens pressure Earths crust mountains

The Heat - Suns energy- thermic energy from the Earths core

-the depth of frost in Romania -0,60- 1,15 m-the geothermal gradient- The temperature increase with depth , with

10 C for each 30-40 m depth

Density The mass of volume unit of the material wich Earth iscompose of.The average value - 5,527 g/cm3

- to surface 2,7-2,8 g/cm3

- to the core 12 g/cm3


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GEOLOGICAL PRESSURE

Df foundation depth

The total load given by

-the building and-its own weightare transmited to the naturalground through the foundation

=hi i

1 = h1

2 = h1 + h2

= h1 + h2 +h33

Monolayer ground

Layered ground

-unit weight of the layer

h-thickness of the layer


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Df foundation depth

Z 0 the depth of active zone

Active zone the depth werethe pressure given by the

foundation, decrease under 20%of geological pressure

Foundation ground, active zone

0,20

= P n

= f ( , Z)

Pn = Pef - i Df

0= 1- In foundation sole

Coefficient (from table)

Net pressureat foundationsole

Effective pressure transmitedby the foundation

The width offoundation sole

The depthconsidered

Foundation

pressure

Geological

pressure

Foundation ground


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EARTH INTERIORTHE EARTHS CRUST (to 80 km depth)

Is thinner beneath the oceans than beneath thecontinents:-Continental crust - 20-80 kmthickness (Granite, schist, gneiss, sedimentaryrockcover)

-Oceanic crust - 10-20 km thickness(Basalt, gabbro in lower crust)The boundary that separate the crust from themantle (beneath it) is called the Mohorovicicdiscontinuity

MANTLE (to 2900 km depth)Litosphere (= the Earths crust and uppermostmantle, together) - to 100 km - solid rockAstenosphere (upper mantle) - to1400 km

- the rocks are close to their melting point(viscous) - magma formationThe boundary is Gutenberg-Wiechertdiscontinuity

THE CORE (about 3400 km radius)- a liquid outer core and a solid inner core

EARTHS COMPOSITION:

The Crust - Si, AlThe Mantle - Si, Mg-upper

-Cr, Iron, Si, Mg, Ni, Mg- lower

The Core -Ni, Iron

-Cross section throughthe Earth

curs 1 - engleza

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