Oasys SIREN

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Oasys SIREN
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Oasys SIREN
Soil Surface
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Response spectrum
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The use of SIREN in the Seismic Design of
Stonecutters Bridge
Jack Pappin
Site Response
Liquefaction
Foundation Design
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Site Response
Bedrock
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Mexico City ground conditions
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(No Transcript)
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Ground conditions
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SIREN - input parameters

• Soil profile
• Density
• Small strain shear modulus G0 g
• G/G with shear strain amplitude
• Input time history selected to match target
  bedrock outcrop response from the seismic hazard
  assessment

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Geophysical methods for G0
G0 rVS2
Down hole insitu test
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Down hole shear wave testing
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Interpretation of Down-hole Seismic Survey
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(No Transcript)
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Variation of G/G0 with shear strain amplitude
1
Gsec
PI 200
100
G0
50
30
15
0
OCR 1 - 15
0
1
0.0001
0.001
0.01
0.1
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Cyclic shear strain ()
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G0(ij) rvs(ij)2 where G0(ij) is the
elastic shear modulus r is
the bulk density of soil and
vs(ij) is the shear wave velocity through soil
v
Vs(vh)
Bender element (vs(vh))
Vs(hv)
Vs(hh)
Bender element
Soil triaxial specimen
Bender element embedded in base platen
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Oasys SIREN
Soil Surface
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Calculated Site response effects
Serviceability
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Calculated Site response effects
Ultimate
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Calculated Site response effects
Structural Integrity Limit State - SILS
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Liquefaction
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Liquefaction
Philippines 1989
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Liquefaction
Philippines 1989
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Liquefaction
Standard method of assessing the likelihood
Percent fines () 35 15 lt5
0.5
Note figure applies for a magnitude 7.5
earthquake
0.4
Liquefaction
0.3
Average peak shear stress / vertical effective
stress
From SIREN
0.2
No Liquefaction
0.1
0
50
10
20
30
40
0
Corrected SPT N value (N1)
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Predicted likelihood of liquefaction
Serviceability
SILS
Ultimate
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Foundation design - Lateral Loads on Piles
Fill
Alluvium
100 30 combination rule
CDG
Bedrock
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Large Diameter Bored Piles
Pile Caps
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Pile group modelling
Piles
Interface elements
Soil Profile
Free field soil lateral displacement
Acceleration
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Bending moments induced in piles