Geotechnics & Foundation Presentation 2011

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Geotechnics & Foundation


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1. Introduction

2. Geology of Singapore

3. Underground Building Works

4. Foundations

5. Earth Retaining Systems


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Geotechnics is

the application of scientific methods and

engineering principles to civil engineering

problems


through acquiring, interpreting, and using

knowledge of materials of the crust of the

earth.


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Bored Piling

Jet Grouting

Contiguous Pile

Soil Nailing

Tunnelling

Grouting

Secant Pile


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Geotechnical engineering

is the branch of engineering concerned


w t t e eng neer ng e av our o eart

materials.


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Jet Grouting


Sheet Piles

Grout Mix Piles

Ground Anchors


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Steel H-Piles


Soil

Improvement


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Geotechnical engineering involves:

site investigation determination of soil/rock properties slope stability


earth retaining method for excavation settlement and wall movement analysis

instrumentation & monitoring system


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1. Introduction



4. Foundations



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fSing

apore

Geology



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Clay mineralsClay minerals are produced mainlyfrom the chemical weathering anddecomposition of feldspars, such asorthoclase and plagioclase, and somemicas.They are small in size and very flakyin shape.


clay soils, e.g. plasticity,compressibility, swelling/shrinkagepotential, lies in the structure of clayminerals.There are three main groups of clayminerals:kaolinites, illites montmorillonites


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Size range of grains

The range of particle sizes encountered in soil is very large:

from boulders with a controlling dimension of over 200mm

down to clay particles less than 0.002mm (2mm).



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In geotechnical

engineering, soils are

considered a three-phase material

composed of:


particles, water andair.

The voids of a soil, the spaces in betweenmineral particles, contain the water and air.


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1. Introduction



4. Foundations



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1. Introduction



4. Foundations



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FOUNDATION DESIGN PROCESS

Design Criteria

Geotechnical capacity


Differential settlement & tilt

Structural strength of foundation elements

Durability


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1. Introduction



4. Foundations5. Earth Retaining Systems


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FORMS OF RETAINING SYSTEMS

Commonly used retaining systems: Sheet Piling


Secant Piling King Post Walls

Diaphragm Walls


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Installation of Diaphragm Wall



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Construction of Contiguous Bored Pile Wall



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Construction of Secant Pile Wall



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Secant Bored Pile Walls



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Steel strutting

forunderground


.


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Installation

of steelsheet piles


piler.


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Soldier piles

with timber

lagging.



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Cofferdamwith 5

layers of

strutting.



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Circular Diaphragm Wall in Taiwan


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Circular Diaphragm Wall in Northern Europe D=90m


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Top down

construction

ofbasemente.


Bored pile

supporting

floor slab.


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Documents

Geotechnics & Foundation Presentation 2011