TYPE OF SAMPLE AND SAMPLING IN GEOTECHNICAL ENGINEERING

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Presentation OnTypes of samples and samplers in
Geotechnical engineering

• Submitted by
• Name Indranil Banerjee
• Roll no CEM18005
• DEPARTMENT OF CIVIL ENGINEERING
• TEZPUR UNIVERSITY
• AUTUMN, 2018

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CONTENTS

• INTRODUCTION
• TYPES 0F SAMPLE
• Disturbed sample
• Undisturbed sample
• SAMPLE DISTURBANCE
• Area ratio
• Inside clearance
• Outside clearance
• TYPES OF SAMPLER
• Open drive sampler
• Piston sampler
• Rotary sampler
• REFERENCE

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• INTRODUCTION
• SOIL SAMPLING Soil sampling is the method of
  collecting insitu soil sample by different
  method in view of performing laboratory
  investigation to determine engineering
  properties of soil.
• SAMPLES In geotechnical engineering soil
  sample is collected to learn about the properties
  of the strata below the ground surface .
• SAMPLER Device used for sampling are known as
  soil sampler.

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TYPES OF SAMPLE disturbed sample
Disturbed sample are of two types
(A) Representative
sample Natural water content ,mineral are
preserved but the soil structure get altered
NON-REPRESENTATIVE SAMPLE
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(B) Non-Representative sample Physical structure
get altered but also there will be alternation in
natural water content and minerals constituents.

• UNDISTURBED SAMPLE Physical structure of the
  soil and its mineral constituents and natural
  water content are preserved.
• Fig-Undisturbed soil sample

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SAMPLE DISTURBANCESample disturbance depends on
the type of sampler and is measured in terms of
three parameters.

• Area ratio
• Inside clearance
• Outside clearance
• Area ratio It should be low as possible ,not
  more
• than 20 in stiff
  formation and 10 for
• sensitive clay.
• Ar ( ??????2-??????2 ??????2
  ) 100

.
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Inside clearance Inside diameter of the sampling
tube is more than the cutting edge , it reduces
the friction between samples and wall of
sampling tube .It should be in between 1-3.
I c ( ??????-?????? ?????? ) 100Outside
clearance The outside diameter of the cutting
edgeis higher than that of sampling tube , it
help easy withdrawal of the sampler. It should
lie between 0-2.Oc ( ??????-?????? ?????? )
100Recovery ratio ???????????? ??????????h
???? ??h?? ???????????? ???? ??h?? ????????
?????????????????????? ??????????h ???? ??h??
?????????????? Rr1 Rrgt1Rrlt1
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TYPES OF SAMPLER

• Open drive sampler Open drive sample
• Is use to collect both disturbed (Representative)
  sample
• and undisturbed sample.

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(A) Thick walled sampler
FIG- Thick wall sampler
(Split spoon sampler)
VENT
CUTTING EDGE
SAMPLING TUBE
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(B) Thin walled sampler
FIG- Thin walled sample (shellby
tube sampler)
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Piston sampler

FIG- Sample from piston sampler
FIG - Piston Sampler(Undisturbed sample))
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Rotary sampler

• It is double wall tube sampler, consist of inner
  tube and outer tube or rotating barrel ,the
• rotating barrel consist of cutting bit which
  rotated and the bits cuts an annular ring, which
• then collected in the inner tube by the rotary
  barrel.

FIG ROTARY SAMPLER
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Rock Recovery ratio ?????????? ????????h??h
???? ???????? ??????????????????
?????????????????????? ????????h?? ????
?????????????? 100TABLE- ROCK
QUALITY DESIGNATION CHART
RQD ROCK QUALITY
lt25 VERY POOR
25-50 POOR
50-75 FAIR
75-90 GOOD
90-100 EXCELLENT
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REFERENCE

1. Basic and applied soil mechanics Gopal Ranjan
   and A.S.R Rao.
2. Foundation analysis and Design Joseph E. Bowles.
3. https//en.wikipedia.org/wiki/Geotechnical_investi
   gation
4. https//www.scribd.com/document/117745153/Types-of
   -Samplers

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• THANK YOU