Class A Centrifuge Prediction of future SG1 of Full Scale Test with Pile Foundation by Marcelo Gonzalez Tarek Abdoun Ricardo Dobry Rensselaer Polytechnic Institute VTC1 June 2 nd, 2008

I.Previous results of SG1 Full Scale test and Centrifuge test II.Free field comparison between centrifuge model tests SG1 and SG1P III.Pile Foundation Behavior, class A centrifuge prediction of full scale test SG1 with pile IV.Final comments Presentation Outline

Free Field Condition Centrifuge Modeling of Full Scale Tests Sloping Ground Condition C-SG1 Scaled Sand, Water

Free Field Condition Centrifuge Modeling of Full Scale Tests Test N o Test Condition Sand Type Method of Construction Field Angle Degree Void Ratio Relative Density % SG1Full ScaleOttawa F#55 Hydraulic Fill C-SG1CentrifugeScaled SandDry Pluviation Sloping Ground Case Test N o Viscosity of Saturating Fluid Cp Hydraulic Conductivity Coefficient cm/sec Compression Index Cc Soil Behavior SG111.2 x ?? C-SG111.1 x x Contractive

Steady and Quasi Steady State Lines for Scaled and Ottawa Sand F#55 (Ottawa Sand F#55 data) Thevanayagam, 2002 Free Field Condition Centrifuge Modeling of Full Scale Tests C-SG1

Free Field Condition Centrifuge Modeling of Full Scale Tests Centrifuge Test No negative Spikes!! top bottom Zoom view Similar amplification Levels Centrifuge Test

Free Field Condition Centrifuge Modeling of Full Scale Tests No difference in Excess Pore water Pressure development Centrifuge Test

Free Field Condition Centrifuge Modeling of Full Scale Tests In both tests, there is a sequence of events such as the following: 1.The lateral soil displacement 2.(r u = 1) [P] 3.Soil isolation [A] Similar Displacement at Surface Centrifuge Test A AA P AP P P

Free Field Condition Centrifuge Modeling of Full Scale Tests We Know that Scaled Sand in this test is mostly contractive (SSL) Shear Strain, % Shear Stress, kPa

Free Field Condition Centrifuge Modeling of Full Scale Tests Stronger soil structure is created when Ottawa Sand F#55 is deposited by dry Pluviation

Presentation Outline I.Previous results of SG1 Full Scale test and Centrifuge test II.Free field comparison between centrifuge model tests SG1 and SG1P III.Pile Foundation Behavior, class A centrifuge prediction of full scale test SG1 with pile IV.Final comments

Pile Foundation Condition SG1P Simulation of SG1-Full Scale But including pile foundation Container: 18m x 9m x 6m

Test N o Test Condition Construction Method Sand Type Field Slope Degree Void Ratio Relative Density % C-SG1PPile FoundationDry PluviationScaled Sand Test N o Viscosity of Saturating Fluid Cp Hydraulic Conductivity Coef. cm/sec Compression Index Cc Soil Behavior C-SG1P11.1 x x Contractive Pile Foundation Condition SG1P

Pile Foundation Condition SG1P Scaled Sand Kp= 1.1 x cm/sec Cc = 6.61 x Ottawa Sand F#55

Accelerations in Free Field of C-SG1P are the same as C-SG1 free field test Pile Foundation Condition SG1P

EPWP on Free Field of C-SG1P are the same as C-SG1 free field test Liquefaction occurs in C-SG1P Pile Foundation Condition SG1P ICP

Soil Lateral Displacements in Free Field of C-SG1P are the same as C-SG1 free field test There is no doubt that we have free field condition in C-SG1P Pile Foundation Condition SG1P

Presentation Outline I.Previous results of SG1 Full Scale test and Centrifuge test II.Free field comparison between centrifuge model tests SG1 and SG1P III.Pile Foundation Behavior, class A centrifuge prediction of full scale test SG1 with pile IV.Final comments

Pile Foundation Condition SG1P

Pile Foundation Condition SG1P

Pile Foundation Condition SG1P Liquefied soil Pressure according to JRA q c = 0.3  t

(a) Polynomial order 2(b) Polynomial order 3(c) Polynomial order 4 Pile Foundation Condition SG1P

(c) Polynomial order 4 preliminary approximation K p = tan 2 (45 +  /2) P p = 0.5(  L 2 K p ) Q L = q L H L + qLqL PpPp For example  =5 o L=0.45H q L = 10 [kN/m] Mo~379 [kN-m] MoMo H QLQL Pile Foundation Condition SG1P

Preliminary approximation K p = tan 2 (45 +  /2) P p = 0.5(  L 2 K p ) Q L = q L H L + qLqL PpPp MoMo H QLQL Factors to consider  friction angle of the soil located in the “cone suction” From contractive soil to dilative soil: 5 o ~ 45 o L, Depth of the “cone suction” 0.3H ~ 0.6H q L Uniform load between 10 to 30 kN/m  K p and P p depend of the compressibility and Permeability of the soil Pile Foundation Condition SG1P

Final Comments Only 15 sec of shaking are enough to produce large lateral spreading of the liquefied soil The pile does not rebound with the firsts two input shaking phases The cone suction zone decrease in dimensions and it is restricted to be close to the pile foundation The earth pressure distribution need to be confirmed to validate future limit equilibrium models

Thank you