Presentation is loading. Please wait.

Presentation is loading. Please wait.

Oasys SIREN. Bedrock Soil Surface Output motion F = F Input motion Displacement.

Similar presentations


Presentation on theme: "Oasys SIREN. Bedrock Soil Surface Output motion F = F Input motion Displacement."— Presentation transcript:

1 Oasys SIREN

2 Bedrock Soil Surface Output motion F = F Input motion Displacement

3 Response spectrum

4 The use of SIREN in the Seismic Design of Stonecutters Bridge Jack Pappin Site Response Liquefaction Foundation Design

5 Bedrock ? Site Response

6 Mexico City ground conditions

7

8 Ground conditions

9 SIREN - input parameters Soil profile Density Small strain shear modulus G 0 g G/G with shear strain amplitude Input time history – selected to match target bedrock outcrop response from the seismic hazard assessment

10 Geophysical methods for G 0 Down hole insitu test G 0 = V S 2

11 Down hole shear wave testing

12 Time Signals received by orthogonal sensors Shear wave arrival through the ground Reverse polarity signals generated by hitting beam from opposite directions P waves or S waves travelling through casing or grout column Interpretation of Down-hole Seismic Survey

13

14 G sec G0G0 1 0 10.00010.0010.010.110 Cyclic shear strain (%) 15 0 30 50 100 PI = 200 OCR = 1 - 15 Variation of G/G0 with shear strain amplitude

15 G 0(ij) = v s(ij) 2 where G 0(ij) is the elastic shear modulus is the bulk density of soil and v s(ij) is the shear wave velocity through soil V s(vh) V s(hh) V s(hv) v Soil triaxial specimen Bender element Bender element (v s(vh) ) Bender element embedded in base platen Bender element (v s(hv) ) Bender element (v s(hh) ) Bender element probe Hall-effect gauge (radial) Hall-effect gauge (axial)

16 Bedrock Soil Surface Output motion F = F Input motion Displacement Oasys SIREN

17 Calculated Site response effects Serviceability

18 Calculated Site response effects Ultimate

19 Calculated Site response effects Structural Integrity Limit State - SILS

20 Liquefaction

21 Philippines 1989 Liquefaction

22 Philippines 1989 Liquefaction

23 Standard method of assessing the likelihood 50 0 102030 0.2 40 0.1 0.3 0.4 0.5 Corrected SPT N value (N 1 ) Average peak shear stress / vertical effective stress Percent fines (%) 35 15 <5 No Liquefaction Liquefaction 0 Note: figure applies for a magnitude 7.5 earthquake From SIREN Liquefaction

24 Predicted likelihood of liquefaction Serviceability SILS Ultimate

25 Bedrock CDG Alluvium Fill 500 250 Bending Moment (kNM) 0 5 10 15 Horizontal displacement (mm) Soil displacement from SIREN Pile displacement 100 : 30 combination rule Foundation design - Lateral Loads on Piles

26 Large Diameter Bored Piles Pile Caps

27 Pile group modelling Soil Profile Piles Interface elements Free field soil lateral displacement Acceleration

28 Bending moments induced in piles


Download ppt "Oasys SIREN. Bedrock Soil Surface Output motion F = F Input motion Displacement."

Similar presentations


Ads by Google