딜라토미터 시험

DMT (Flat Dilatometer Test)

A Flat Dilatometer probe consists in a steel blade with a circular membrane in one of its sides. The membrane has electrical

DMT (flat Dilatometer Test)

딜라토미터 시험

- 원형 멤브레인을 가스압력으로 수평방향으로 수축과 팽창시켜, 이 때 팽창과 수축 변위에서의 압 력으로부터 지반의 특성을 추정하는 실험

1 2 3

1.05( ) 0.05( )

p A A B B

p B B

p C A

     

  

  

DMT (flat Dilatometer Test)

1 2 3

1.05( ) 0.05( )

p A A B B

p B B

p C A

     

  

  

D

2 1

2

D

1 '

0

D

2 1

1

(dilatometer modulus, E ) 34.7( )

1

(lateral stress index, K )

(material or deposit index, I )

s D

D

v

D

E E p p

p u K

p p

I p u





  



 

 



딜라토미터 계수

수평응력지수

지반지수

PMT (Pressuremeter Test)

http://www.ce.gatech.edu/~geosys/Faculty/Mayne/Research/index.html

Field vane shear test, FVST

2

6

1

10 2 3

(

u

s T K

D H D

K H





 

        비배수전단강도

여기서 D는베인의지름 cm), H는베인의높이(cm)

현장 베인 시험

- 연약하고 포화된 점성토 지반의 비배수 전단강도를 추정하기 위해 실시하는 현장 시험

Undrained shear strength (s _u ) measurement Field Vane

s

(mob) = s

(FV)

Correction factor  to account for:

1. Direction of shearing 2. Time to failure

3. Disturbance

4. Progressive failure

Seismic Reflection Test

Seismic Refraction Test

Vertical Geophones Source

(Plate)

Rock: V _p2 Soil: V _p1

oscilloscope

x1 x2 x3 x4

t1 t2

t3 t4

Note: V

< V

z _R

Determine depth to rock layer, z _R

http://www.ce.gatech.edu/~geosys/Faculty/Mayne/Research/index.html

Crosshole Testing

Oscilloscope

Downhole Hammer

(Source) ^Velocity

Transducer (Geophone Receiver)

t

Shear Wave Velocity:

V _s = x/t

Test Depth

ASTM D 4428

Pump

Downhole Testing

Oscilloscope

Cased Borehole

Test Depth Interval

Horizontal Velocity Transducers

(Geophone Receivers) packer

Pump

Horizontal Plank with normal load

Shear Wave Velocity:

V _s = R/t

z ₁

z ₂

t

R ₁ ² = z ₁ ² + x ² R ₂ ² = z ₂ ² + x ²

x

Hammer

http://www.ce.gatech.edu/~geosys/Faculty/Mayne/Research/index.html

SASW, MASW

Boring Log