Prepared by J. P. Singh & Associates in association with Mohamed Ashour, Ph.D., PE

1. Computer Program DFSAPDeep Foundation System Analysis ProgramBased on Strain Wedge Method • Prepared by • J. P. Singh & Associates • in association with • Mohamed Ashour, Ph.D., PE • West Virginia University Tech • and • Gary Norris Ph.D., PE • University of Nevada, Reno • APRIL 3/4, 2006

2. SOIL LIQUEFACTION AND LATERAL SPREADING OF SOIL

3. Current Available Procedures That Assess the Pile/Shaft Behavior in Liquefied Soils (Using the Traditional P-y Curve): 1. Construction of the p-y curve of soft clay based on the residual strength of liquefied sand presented by Seed and Harder (1990) 2. The use of random Pmult < 1 to reduce the stiffness of the traditional p-y curve of sand 3. Reduce the unit weight of liquefied sand with the amount of Ru (Earthquake effect in the free-field ) and then build the traditional p-y curve of sand based on the new value of the sand unit weight. (proposed by Brown based on Cooper River Test)

4. Fig. 1 Corrected blowcount vs. residual strength (Seed and Harder, 1990)

5. P-Y Curve of Completely Liquefied Soil Lower Limit of Sr Treasure Island Test Result (Rollins and Ashford) Upper Limit of Sr using soft clay p-y curve Soil-Pile Reaction, p Corrected blowcount vs. residual strength, Sr (Seed and Harder, 1990) API Procedure 19 Pile Deflection, y

6. Post-liquefaction stress-strain behavior of partially liquefied sand (Duc < s3c and. Ru <1) Post-liquefaction stress-strain behavior of completely liquefied sand (Duc = s3c and Ru =1) Deviator Stress, sd d = 2 Sr Axial Strain, e xo • Fig. 1 Subsequent undrained stress-strain behavior of sand that has experienced partial or complete liquefaction

7. Water Pressure in the Free- and Near-Field Due to the Earthquake Shaking and Equivalent Static Load from the Superstructure A B Fully Liquefied Soil (Ru =1) Partially Liquefied Soil (Ru < 1)

8. Ru = 1 Ru = 1 • Post-liquefaction undrained • stress-strain behavior of • completely liquefied Fraser sand Ru = 0.88

9. Fig. 2 Effect of Cyclic Loading upon Subsequent Undrained Stress-Strain Relationship for Sacramento River Sand (Dr = 40%) (Seed 1979)

10. Validation Example for Pile and Pile Group in Liquefiable soil profile Treasure Island Test Report, Chapter 6

11. Soil Profile and Properties at the Treasure Island Test L o n g i t u d i n a l Upper Limit of Sr using soft clay p-y curve S t e e l Steel Shell Soil-Pile Reaction, p x x Lower Limit of Sr Treasure Island Test Result (Rollins and Ashford) API Procedure S h a f t W i d t h Pile Deflection,y Peak Ground Acceleration (amax) = 0.1 g Earthquake Magnitude = 6.5 Induced Porewater Pressure Ratio (ru) = 0.9 - 1.0

12. TREASURE ISLAND TEST

15. 500 N k C I S S , 0 . 6 1 m , 400 o E I = 4 4 8 3 2 0 k N - m 2 P o s t - L i q u e f a c t i o n P n ( u + u ) o , i x s , f f x s , n f d t c 300 a a f o e u L q i L d 200 - o a N e H - O b s e r v e d 100 e l P r e d i c t e d ( S W M ) i P P r e d i c t e d ( C o m 6 2 4 ) 0 0 100 200 300 400 P i l e - H e a d D e f l e c t i o n , Y o , m m

16. Pile-Head Response (Yo vs. Po) for 0.61-m Diameter CISS at Treasure Island Test.

17. API (Pmult = 0.3) p-y Curve at 1.5 m Below Ground (0.61-m Diameter CISS )

18. 0.2 m Below Ground 1.5 m Below Ground 3.2 m Below Ground p-y Curve of 0.61-m Diameter CISS in Liquefied Soil. (Treasure Island, After Rollins et al. 2005)

19. p-y Curve Empirical Formula in Liquefied Sand by Rollins et al. 2005 p(d=324 mm) = A(By)Cfor Dr = 50% where: A = 3 x 10-7 (z+1)6.05, B = 2.8 (z+1)0.11 C = 2.85(z+1)-0.41 z is depth in (m) y is lateral deflection (mm) pmultiplier = 3.81 ln d + 5.6 p = p (d=324 mm) xpmultiplier

20. Curve # 1 Pile Load (kN) Curve # 2 Deflection at Load Point (mm) Pile-Head Response (Yo vs. Po) for an Isolated 0.324-m Diameter CISS at Treasure Island Test.

21. p-y Curve of 0.324-m Diameter CISS in Liquefied Soil (Treasure Island)

22. Responses of Individual Piles in a 3 x 3 Pile Group in Non-Liquefied Soil Profile at the Treasure Island Test (Rollins et al. 2005a)

23. Curve # 1 Curve # 1 Pile Load (kN) Curve # 2 Curve # 2 Deflection at Load Point (mm) Pile-Head Response (Yg vs. Pg) for a 3 x 3 CISS Pile Group (0.324-m Diameter) at Treasure Island Test. (After Rollins et al. 2005)

24. p-y Curve of a 3 x 3 Pile Group in Liquefied Soil (Treasure Island, 0.324-m CISS) B, C E A

25. Lateral Soil Spread

26. Bartlett and Youd, 1995 (Current Practice) Deviator Stress, sd Soil Lateral Displacement (Xo) in DFSAP xo Axial Strain, e Stress-Strain Behavior of Fully Liquefied Sand SOIL LATERAL SPREADING CHALLANGES: • Amount of Soil Lateral Displacement • Mobilized Driving Lateral Forces • Acting on Piles and Generated • by Crust Layer(s) • Varying Strength of Liquefied Soil(s)

27. (Ishihara)

28. Shaft Cross Section Liquefied Soil Soil Flow Around LATERAL SOIL SPREAD Shaft Diameter

30. Pile head load = 100 kN Pile head moment = 316 kN-m No-Liquefaction Liquefaction Liquefaction + Lateral Spread

31. Pile head load = 100 kN Pile head moment = 316 kN-m No-Liquefaction Liquefaction Liquefaction + Lateral Spread

32. Hokkaido Island Test (Ashford et al. 2006, ASCE J.) LATERAL SOIL SPREAD, TEST 1

33. Hokkaido Island Test (Ashford et al. 2006) LATERAL SOIL SPREAD Peak Ground Acceleration (amax) = 0.4 g Earthquake Magnitude = 6.0 Induced Porewater Pressure Ratio (ru) = 1.0

34. DFSAP 0.314-m-Diameter Steel Pipe Pile Hokkaido Island Test (Ashford et al. 2006, ASCE J.) LATERAL SOIL SPREAD, ISOLATED FREE-HEAD PILE

35. DFSAP Hokkaido Island Test (Ashford et al. 2006, ASCE J.) LATERAL SOIL SPREAD, ISOLATED FREE-HEAD PILE

36. Rotation = 1 Deg. (Not fully fixed) DFSAP Steel Pipe Pile Hokkaido Island Test (Ashford et al. 2006, ASCE J.) 2 X 2 FIXED-HEAD PILE GROUP WITH CAP

37. UC Davis, Centrifuge Test (Brandenberg and Boulanger, 2004) Cu= 44 kPa  = 16 kN/m3 Clay  = 6 kN/m3, Dr = 21-35%  = 30o, 50= 0.01 Loose Sand  = 7 kN/m3, Dr = 69-83%  = 36o, 50= 0.004 Dense Sand Pile Length (m) Diameter (m) Wall Thick. (m) Pile Spacing (m) Pile Cap Height (m) Pile Cap Width (m) Pile Cap Length (m) 23.5 1.17 0.051 4.6 2.2 9.2 14.3

39. Bending Moment UC Davis, Centrifuge Test on 2 x 3 Fixed-Head Pile Group (After Brandenberg and Boulanger, 2004) Pile Displacement amax = 0.67 g Magnitude = 6.5

40. p-y Curves at Different Depths for a Lateral Soil Spreading Case (UC Davis Test, amax = 0.3g)

41. Input Data • 1. Shaft/Pile Properties • Shaft length and diameter • Shaft-head location above ground • Moment and axial load at shaft head • Type of the shaft cross-section and material • Uniaxial fc28 of concrete • Percentage of rebars • Percentage of horizontal steel • Thickness of steel shell (if any) • Fy of steel (nonlinear modeling)

42. Input Data (Continue) • 2. Soil properties: • Thickness of soil layer of soil layer • Effective unit weight of soil () • Normal strain of sand at 50% strength, 50% • Uniformity coefficient (Cu) • Angle of internal friction, (Sand) • Undrained shear strength, Su (Clay) • Relative density (Dr) • Percentage of fines (passing from sieve # 200) • Sand grain roundness parameter () • 3. Earthquake • Magnitude, M • Peak ground acceleration, amax

43. QUESTIONS ????