MY CONNECTIONS TO JERRY

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2 MY CONNECTIONS TO JERRY Research Engineer, AF Weapons Lab 1963 My first job after M.S. as project monitor on Jerry s AFWL research. Invited to apply to Ph.D. program at Purdue. Tokyo ISSMFE Conference 1977, post conference tour with Jerry and Beryl, Jorg Osterberg and others.

3 GROUND SETTLEMENT FROM PILE DRIVING GENERAL CONCEPTS EXAMPLES FROM PRACTICE

4 HAMMER PARTICLE VELOCITY PILE SHEAR WA VE VELOCITY ELASTO-PLASTIC ZONE ELASTIC ZONE P L A S T I C Z ZO ON NE Z E { ż 1 m/s SHEAR STRAIN SHEAR STRAIN 10-1 % 10-3 % < 10-3 %

5 COMPONENTS OF PILE VIBRATION ANALYSIS TRANSFER OF ENERGY FROM PILE TO SOIL DISIPATION OF ENERGY THROUGH SOIL DISIPATION OF ENERGY S THROUGH SOIL THRESHOLD OF SETTLEMENT CAUSING VIBRATIONS

6 GENERATION OF GROUND DISTURBANCE TRANSFER OF DRIVING ENERGY INTO SURROUNDING GROUND

7 D = f(µ) CYLINDRICAL SHEAR WAVE FRONT SHAFT RESISTANCE TIP RESISTANCE SPHERICAL WAVE FRONT

8 TIP RESISTANCE GOBLE (1980) R T = J Z P ż IWANOWSKI AND BODARE (1988) J = Damping or loss factor Z P = Pile impedance ż = particle velocity in pile J = ratio of pile and soil impedance and also related to K in Heckman & Hagerty (1978) MASSARSCH AND FELLENIUS (2008) R T = Z P v o Z P = A P v ps ρ s v o = Hammer impact velocity

9 SHAFT RESISTANCE MASSARSCH AND FELLENIUS (2008) R S = z s ż A C z s = specific impendence of soil ż = particle velocity in pile A C = contact area between soil and pile ż = t f / v s ρ (often > 12 in/sec) t f = shearing strength of soil v s = shear wave velocity ρ = mass density of soil {(ż) max 1 m/s Observed in densification studies}

10 DISSIPATION OF ENERGY WITH DISTANCE GEOMETRICAL AND MATERIAL DAMPING

11 EQUATIONS DESCRIBING ENERGY DISIPATION BORNITZ EQUATION w = w 1 (r 1 /r) n exp[-α(r r 1 )] w 1 = amplitude at known distance r 1 w = amplitude at any distance r r 1 = distance from source to point of known amplitude r = distance from source to any point n = coefficient depending on type of wave n = 1 for body waves in half-space n = 2 for body waves along surface n = 0.5 for Rayleigh waves α = coefficient of attenuation

12 N < 5 5< N < 15 15< N < 50 N > 50

13 EQUATIONS DESCRIBING ENERGY DISSIPATION PSEUDO - ATTENUATION ż = k [D/ E] -N ż = peak particle velocity k = intercept at 1 energy unit D = distance from source E = energy of source N = slope of line on log-log plot of ż vs scaled distance

14 P S E U D O A T T E N U A T I O N P E A K P A R T I C L E V E L O C I T Y SCALED DISTANCE (D/ E)

15 VIBRATIONS CAUSING SETTLEMENT SHEARING STRAIN AND VOLUMETRIC STRAIN

16 SHEARING STRAIN γ = ż / v s (For harmonic motion only) γ equivalent for non-harmonic vibrations, displacement gradient suggested by Brandenberg et al (2009) u z / y ż = σ Z v p / E p (free end of pile)

17 THRESHOLD STRAIN SILVER & SEED (1971) γ t 0.01% YOUD (1972) γ t = 0.01 % (limit of his tests) DOBRY (1983) γ t = 0.01% (for liquefaction) HSU & VUCETIC (2004) γ t = <0.01% (10 cycles) MASSARSCH (2008) γ t = % (many cycles) BRANDENBERG ET AL (2009) γ t = <0.01%

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19 VARIABLES AFFECTING γ t N O RELATIVE DENSITY VOID RATIO EFFECTIVE CONFINING PRESSURE Y E S NUMBER OF CYCLES STRAIN LEVEL

20 EXAMPLE 1 BLACKWATER RIVER BRIDGE I-10 PENSACOLA, FLORIDA

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33 MEASURED & PREDICTED SETTLEMENT PREDICTED MEASURED ( H) max = 1.47 ft H H < 0.01 ft

34 BORDEN & SHAO (1995)

35 EXAMPLE 2 INFRASTRUCTURE REHABILITATION INTERSTATE BRIDGE REPLACEMENT

36 1950s BRIDGE RETAINING WALL 3 SPANS SPREAD FOOTINGS PROPOSED REPLACEMENT RETAINING WALL 1 SPAN PILE FOUNDATIONS

37 DEPTH (ft) CL SP SP-ML SP HP 12x53 1 2a 2b 2c 8 < N < 12 (N) avg = 6 8 < N < PILES VIBRO DRIVEN TO THIS LAYER SW 3 N > IMPACT DRIVEN TO FINAL DEPTH

38 DYNAMIC PILE ANALYSIS DELMAG : 40 kip-ft

39 DRIVING 5 PILES WITH D HAMMER, 300 BLOWS EACH 40 K-FT

40 PILECO D30-32 : 70 FT-KIPS DYNAMIC PILE ANALYSIS

41 DRIVING 3 PILES WITH D30-32 HAMMER, 300 BLOWS EACH 70 K-FT

42 SUMMARY D = f(µ) CYLINDRICAL SHEAR WAVE FRONT SHAFT RESISTANCE TIP RESISTANCE SPHERICAL WAVE FRONT

43 HAMMER PARTICLE VELOCITY PILE SHEAR WA VE VELOCITY ELASTO-PLASTIC ZONE ELASTIC ZONE THREE ELEMENTS TO PREDICT SETTLEMENT P L A S T I C Z ZO ON NE Z E 1) Pile to Soil Energy Transfer 2) Transmission of Energy through Soil 3) Vibration Level Required to Cause Settlement { ż 1 m/s SHEAR STRAIN SHEAR STRAIN 10-1 % 10-3 % < 10-3 %

44 ACKNOWLEDGE CONTRIBUTORS John Schmertmann David Crapps Larry Jedele Michael Thelen Robert Rabeler Rainer Messarsch (Vibisol International Sweden)

45 FINALLY CONGRATULATIONS TO VINCE AND ROXANNE ON A BRILLIANT CAREER THANK YOU! DICK