Soil Mechanics

Jan Záleský, PhD.Department of Geotechnics

Office: B 506 Office Hours: Tuesday: 09:00 – 09:50

Friday: 09:00 – 09:50Phone: 224 354 551, Fax: 233 334 206

Handy: +420 602 316 383E-mail: zalesky@fsv.cvut.cz

Geomechanics / Geotechnics(Science and Application, Technology)

• Soil Mechanics– soil description & testing, behaviour, prognosis, etc.

• Rock Mechanics– rock description & testing, behaviour, prognosis, etc.

• Foundation Engineering– spread / pile footing, foundation pit design, etc.

• Underground openings– tunnels, caverns, etc.

• Monitoring– verification of assumptions being stated at design stage,– in-situ (scale 1:1) - structure & soil/rock mass behaviour,– basic step in application of Observational Method.

Is there any change?

Laboratory and field testingAnalogy?

Shallow footing:bearing capacity and settlement?

Lateral Stress, distribution andwall stability

Lateral stress – how much?

Fondations:From Geology to Soil Mechanics

SoilMechanics:

Theory,

testing,

application,

Knowledge,

experience,

t h l

Investigation boring – TV 01

Geomaterials ⇒ Classification

Fine soilsWeathered rock base

Coarse soils

Grain Silo in Transcona (Canada)

Tower of Pisa (Italy)

?Settlement and or

Soil Collapse

Failure modes of strip footing

(a) General shear, (b) local shear, (c) punching shear in: dense / stiff soil high compressible soils (HCS) HCS / considerable depth.

Rabenov site – North Bohemia“Auxiliary reference point

Borehole MPD 02

BoreholeMPD 01

Slip types

General slip surface0.

00

10.0

0

20.0

0

30.0

0

40.0

0

50.0

0

60.0

0

70.0

0

80.0

0

90.0

0

100.

00

100.

25

Gabion Wall Gravel Stabilizing Berm Road

Patio damagd by slide

SysGeo - Italy

Soil

• Where does it come from?– Weathering of earth crust (mechanical,

chemical)• residual soils / not transported• sedimented soils / transported

– Sediments» eluvial, fluvial, deluvial, glacial, eolic, limnic, marine,

antropogenic

• Terrestrial / extra-terrestrial ?

Side-Hill Cut

Silty shaleAlta Badia - Italy

Soil• Composition & Description

– phases: fluid / liquid / solid• History

– virgin:• normally consolidated / over-consolidated

– made ground• Characterisation and testing

– strength– deformation

Solids - coarse grains

• Single grain structure– boulders– cobbles– gravel– sand

Solids - fine grains

• Clay structures – (a) dispersed, (b) flocculated, (c) book-house,

(d) turbostatic, (e) example of natural clay

Clay minerals

– Basic units of clay minerals– (a) scheme, (b) symbol

Clay minerals