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Thesis_Jun7_2012

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This document summarizes a thesis presented to fulfill requirements for a Master's degree in Civil Engineering. The thesis investigated the load transfer mechanisms of drilled shafts in weak porous limestone through field testing and analysis. Two full-scale load tests were performed on drilled shafts constructed at a test site underlain by Aymamon limestone. Results from instrumentation during loading were analyzed to evaluate unit side shear and end bearing resistance values, and compare with empirical relationships. The testing aimed to provide a basis for a load transfer criterion for drilled shaft design in weak porous rock conditions.

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AXIAL COMPRESSION LOAD TRANSFER MECHANISMS OF DRILLED SHAFTS IN WEAK POROUS LIMESTONE Presentation of thesis in partial fulfill of the requirements for the degree of Master of Science in Civil Engineering Jos辿 Roberto Ram鱈rez Hern叩ndez University of Puerto Rico at Mayaguez Advisor: Dr. Miguel A. Pando L坦pez Mayag端ez, Puerto Rico Thursday June 7, 2012
Index Goals and specific aims Introduction Site Characterization Field test program Load test results Conclusions Acknowledgments Mayag端ez, Puerto Rico Thursday June 7, 2012 2
Goals and specific aims Provide a basis for a load transfer criterion and evaluate experimentally the characteristics of the ultimate unit side resistance of drilled shafts in weak porous rock of Puerto Rico Design an experimental study of load test of drilled shafts based on high precision instrumentation Analyze data from the field tests and compare the prediction based on empirical relationships Classify and establish a geotechnical and geological characterization of the limestone rock from La Monta単a farm in Aguadilla, PR Mayag端ez, Puerto Rico Thursday June 7, 2012 3
Compressive axial bearing capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 4
Compressive axial bearing capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 5 Idealized load-displacement behavior (after Carter & Kulhawy, 1988)
Drilled shaft axial capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 6 Load transfer mechanism for socketed shaft (adapted from Zhang, 1998)
Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 7 Factors affecting the max for drilled shafts in rock Factors related to the construction Technique Interface roughness Length of time borehole remains open prior to concreting Destroyed or intact base resistance Factors related to drilled shaft geometry Length Diameter Factors related to the load test method Rate of load applied
Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 8 Interface roughness Wall roughness classification from Pells et al. (1980) Roughness Classification Description R1 Straight, smooth-side shaft, grooves or indentation less than 1.00 mm deep R2 Grooves of depth 1-4 mm, width greater than 2 mm, at spacing 50 to 200 mm. R3 Grooves of depth 4-10 mm, width > 5 mm, at spacing 50 to 200 mm. R4 Grooves or undulations of depth greater than 10, width > 10mm, at spacing 50 to 200 mm. Parameters for defining shaft wall roughness (after Horvath et al., 1980 and Kodikara et al., 1992) Upper and lower bound guidelines for effective roughness adapted from (Seidel and Collingwood, 2001)
Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 9 Factors related to drilled shaft geometry Unit side shear versus displacement for drilled shafts socket in rock with qu = 3 MPa (after Baycan, 1996)
Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 10 Factors related to the load test method Comparison of typical Load-Displacement behavior four test procedures (adapted from Fellenius, 1975) 0 20 40 60 80 100 120 140 160 180 0 1 2 3 4 5 6 7 8 Load Displacement CRP Quick ML Cyclic
Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 11 Reference 留 硫 C 1 Rosenberg and Jouneaux (1976) 0.34 0.51 1.05 2 Horvath (1978) 0.33 0.50 1.04 3 Horvath and Kenney (1979) lower bound 0.21 0.50 0.65 Horvath and Kenney (1979) upper bound 0.25 0.50 0.78 4 Meigh and Wolski (1979) 0.22 0.60 0.55 5 Reynolds and Kaderabek (1980) 0.30 1.00 0.30 6 Pells et al. (1980) R1, R2 & R3 0.40 0.50 1.26 Pells et al. (1980) R4 0.80 0.50 2.52 7 Williams et al. (1980) 0.44 0.37 1.85 8 Horvath (1982) smooth 0.20 0.50 0.63 9 Horvath (1982) roughness 0.30 0.50 0.95 10 Gupton and Logan (1984) 0.20 1.00 0.20 Reference 留 硫 C 11 Rowe and Armitage (1984) smooth 0.45 0.50 1.42 Rowe and Armitage (1984) roughness 0.60 0.50 1.89 12 Reese and O'Neill (1987) 0.15 1.00 0.15 13 Carter and Kulhawy (1988) 0.2 0.50 0.63 14 Toh et al. (1989) 0.25 1.00 0.25 15 Kulhawy and Phoon (1993) 0.35 0.50 1.10 16 O'Neill and Reese (1999) 0.21 0.50 0.66 17 Zhang and Einstein (1998) lower bound 0.20 0.50 0.63 Zhang and Einstein (1999) upper bound 0.40 0.50 1.26 18 Prakoso (2002) lower bound 0.20 0.50 0.63 Prakoso (2002) upper bound 0.32 0.50 1.00 19 Kulhawy et al. (2005) 0.32 0.50 1.00 20 Turner (2006) 0.32 0.50 1.00 Summary of relations between t and qu (expanded version from ONeill et al., 1996)
Unit end bearing resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 12 Design Method Teng (1962) [5-8] 1 Coates (1967) 3 1 Rowe and Armitage (1987) 2.7 1 Zhang and Einstein (1998) 4.5 1 ARGEMA (1992) [3-6.6] 0.5 Empirical relationships between and (expanded version from Zhang & Einstein, 1998) Between 10% - 20% (Williams et al., 1980; Carter & Kulhawy, 1988) A significant relative movement between concrete and rock is necessary to achieve the total end bearing resistance (Qb) Some methods proposed for predict (Qb) are based on elastic solutions and depend on the embedment ratio (L/B) and the rate of stiffness (Ec/Er) Theoretical base load transfer (adapted from Rowe and Armitage, 1987b) =
Weak rock / IGMs definition Mayag端ez, Puerto Rico Thursday June 7, 2012 13 Weak rock Weathered and broken rock (BS, 8004) Indurated soil (Oliveira, 1993) Soft rock (Johnston, 1989) Intermediate geo-material IGM (FHWA, 1995) IGM strength classification based on qu versus (adapted from Kulhawy and Phoon, 1993)
Summary Mayag端ez, Puerto Rico Thursday June 7, 2012 14 Demand of loads of great magnitude 1976 2006 Range of estimation to predict Qs 86% 93% The 27.5% geomorphology area of Puerto Rico is conformed fro three karst zones (North, South and disperse) $ versus capacity 0 5 10 15 20 25 30 10 30 50 70 90 110 130 150 max/Pa qu/Pa Rosenberg and Jouneaux (1976) Horvath (1978) Horvath and Kenney (1979) lower bound Horvath and Kenney (1979) upper bound Meigh and Wolski (1979) Reynolds and Kaderabek (1980) Pells et al. (1980) R1, R2 & R3 Pells et al. (1980) R4 Williams et al. (1980) Horvath (1982) smooth Horvath (1982) roughness Gupton and Logan (1984) Rowe and Armitage (1984) smooth Rowe and Armitage (1984) roughness Reese and O'Neill (1987) Carter and Kulhawy (1988) Toh et al. (1989) Kulhawy and Phoon (1993) O'Neill and Reese (1999) Zhang and Einstein (1998) lower bound Zhang and Einstein (1999) upper bound Prakoso (2002) lower bound Kulhawy et al. (2005) Turner (2006)
Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 15 Location General location map of test site not to scale (adapted from www.mapsof.net 息 2012) Aerial image showing location of experimental farm La Monta単a (from Google Earth 息2012) Aerial images showing general location of test site (from Google Earth 息 2012)
Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 16 Geology Geological map of Puerto Rico (adapted from Renken et al., 2002) Elevation view of the North Coast Belt of Puerto Rico (adapted from Renken et al., 2002) Ta
Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 17 Engineering properties Drilled shafts load test and site investigation layout (not to scale) Thermo-gravimetric analyses (TGA) of Aymam坦n limestone
Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 18 Boring log DS_A2 Drilled shafts load test and site investigation layout (not to scale) Stress-Strain diagram for Aymam坦n limestone (UCS) test
Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 19 General test layout Layout of load test arrangement Setup and arrangement of axial compressive load test
Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 20 Field test program Layout of load test arrangement 1 2 0 10 20 30 40 50 60 70 0 50 100 150 200 250 300 time(min) Load (kips) Duration of Load Test 0 5 10 15 20 25 30 0 50 100 150 200 250 300 time(sec) Load (kips) Duration of Load Test
Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 21 Construction of drilled shafts Layout of load test arrangement 1 2 DS_LT 1 DS_LT 2 0 5 10 15 20 0.1 1 10 100 1000 Effectiveheightofroughness-r(mm) qu (Mpa) Upper Border Bottom Border DS_LT 1 DS_LT 2 DS_LT 1 Parameter Values Reference Roughness Classification R3 Pells et al (1980) Medium to high RF 0.20 Horvath et al (1980) Low to medium hm 4.67 mm Kodikara et al (1992) Medium isd 5.51 re 4.67 Seidel y Collingwood (2001) See Figure DS_LT 2 Parameter Values Reference Roughness Classification R3 Pells et al (1980) Medium to high RF 0.21 Horvath et al (1980) Low to medium hm 4.78 mm Kodikara et al (1992) Medium isd 5.20 re 4.78 Seidel y Collingwood (2001) See Figure Effective height roughness versus qu for drilled shafts DS_LT1 and DS_LT2 (after Seidel and Collingwood, 2001) Summary of roughness parameters for drilled shafts DS_LT 1 and DS_LT 2Summary of roughness parameters for drilled shafts DS_LT 1 and DS_LT 2
Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 22 Construction of drilled shafts
Results Mayag端ez, Puerto Rico Thursday June 7, 2012 23 DS_LT1 0.974 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0 50 100 150 200 250 300 Displacementoftoppile(in) Load (kips) 1 sequence 2 sequence 3 sequence Load versus displacement for the drilled shaft DS_LT 1 0 200 400 600 800 1,000 1,200 0 50 100 150 200 250 300 袖strain Load (kips) EGP1 (袖) level 46.25 in EGP2 (袖) level 34.35 in EGP3 (袖) level 21.75 in EGP4 (袖) level 9.75 in EGP5 (袖) level - 4.25 in Load applied versus strains for drilled shaft DS_LT 1
Results Mayag端ez, Puerto Rico Thursday June 7, 2012 24 DS_LT2 Load versus displacement for the drilled shaft DS_LT 2 0.773 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0 50 100 150 200 250 300 Displacementoftoppile(in) Load (kips) 0 200 400 600 800 1,000 1,200 0 50 100 150 200 250 300 袖strain Load (kips) EGP1 (袖) level 49.5 in EGP2 (袖) level 36.5 in EGP3 (袖) level 23.25 in EGP4 (袖) level 9.5 in EGP5 (袖) level -4.5 in Load applied versus strain for drilled shaft DS_LT 2
Results Mayag端ez, Puerto Rico Thursday June 7, 2012 25 250.56 12.85 -12 0 12 24 36 48 60 0 100 200 300 Depth(in) Load (kips) Q= 15 kips Q= 25 kips Q= 40 kips Q= 45 kips Q= 65 kips Q= 100 kips Q= 165 kips Q= 215 kips Q= 250 kips Qs max Qs min Load distributions for drilled shaft DS_LT 1 272.20 5.46 -12 0 12 24 36 48 60 0 100 200 300 Depth(in) Load (kips) Q= 10 kips Q= 25 kips Q= 35 kips Q= 45 kips Q= 65 kips Q= 100 kips Q= 150 kips Q= 200 kips Q= 230 kips Q= 250 kips Q= 270 kips Q max Q min Load distributions for drilled shaft DS_LT 2
Results Mayag端ez, Puerto Rico Thursday June 7, 2012 26 Maximum skin friction mobilized for drilled shaft DS_LT 1 Maximum skin friction mobilized for drilled shaft DS_LT 2 0 10 20 30 40 50 0 200 400 600 Depth(in) Unit side shear resistance mobilized (psi) Q=20 kips Q=25 kips Q=45 kips Q= 67 kips Q= 100 kips Q= 165 kips Q= 215 kips Q= 250 kips 0 10 20 30 40 50 0 200 400 600 Depth(in) Unit side shear resistance mobilized (psi) Q= 272 kips Q= 200 kips Q= 150 kips Q= 100 kips Q= 75 kips Q= 50 kips Q= 25 kips Q= 10 kips
Comparative prediction - measured Mayag端ez, Puerto Rico Thursday June 7, 2012 27 275 250 333.21 49.01 0 100 200 300 400 500 600 700 800 150 350 550 750 950 1150 1350 Drilledshaftloadcapacity-Qu(psi) Unconfined compressive strength - qu (psi) Carter and Kulhawy (1988) Pells et al. (1980) R4 Limestone DS_LT 2 (Q measured) DS_LT 1 (Q measured) Qu DS_LT 2 est Qu DS_LT 1 est Qtu e
Conclusions Mayag端ez, Puerto Rico Thursday June 7, 2012 28 Shafts roughness index factor Shaft geometry - diameter and length Rate of load method Classification of limestone from the Aymam坦n formation in La Montana farm Pells et al. (1980). other correlations The behavior of the drilled shafts tested Future work La Montana farm
Acknowledgments Family Geo-Cim Inc, Dywidag-Systems International, MS Drills, Structural Steel Manufacturing, Inc. Mr. A単eses and all the people which work in the La Monta単a farm Augusto Ortiz, Manuel Collazo Dr. Ricardo Ramos, Dr. Daniel Wendichansky, and Dr. Miguel Pando Friends PRSN Christa and Victor Finally, thanks Ana, Andr辿 & Mateo Puerto Rico Seismic Network (PRSN) January 17th, 2012 29
Puerto Rico Seismic Network (PRSN) January 17th, 2012 30

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Thesis_Jun7_2012

  • 1. AXIAL COMPRESSION LOAD TRANSFER MECHANISMS OF DRILLED SHAFTS IN WEAK POROUS LIMESTONE Presentation of thesis in partial fulfill of the requirements for the degree of Master of Science in Civil Engineering Jos辿 Roberto Ram鱈rez Hern叩ndez University of Puerto Rico at Mayaguez Advisor: Dr. Miguel A. Pando L坦pez Mayag端ez, Puerto Rico Thursday June 7, 2012
  • 2. Index Goals and specific aims Introduction Site Characterization Field test program Load test results Conclusions Acknowledgments Mayag端ez, Puerto Rico Thursday June 7, 2012 2
  • 3. Goals and specific aims Provide a basis for a load transfer criterion and evaluate experimentally the characteristics of the ultimate unit side resistance of drilled shafts in weak porous rock of Puerto Rico Design an experimental study of load test of drilled shafts based on high precision instrumentation Analyze data from the field tests and compare the prediction based on empirical relationships Classify and establish a geotechnical and geological characterization of the limestone rock from La Monta単a farm in Aguadilla, PR Mayag端ez, Puerto Rico Thursday June 7, 2012 3
  • 4. Compressive axial bearing capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 4
  • 5. Compressive axial bearing capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 5 Idealized load-displacement behavior (after Carter & Kulhawy, 1988)
  • 6. Drilled shaft axial capacity Mayag端ez, Puerto Rico Thursday June 7, 2012 6 Load transfer mechanism for socketed shaft (adapted from Zhang, 1998)
  • 7. Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 7 Factors affecting the max for drilled shafts in rock Factors related to the construction Technique Interface roughness Length of time borehole remains open prior to concreting Destroyed or intact base resistance Factors related to drilled shaft geometry Length Diameter Factors related to the load test method Rate of load applied
  • 8. Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 8 Interface roughness Wall roughness classification from Pells et al. (1980) Roughness Classification Description R1 Straight, smooth-side shaft, grooves or indentation less than 1.00 mm deep R2 Grooves of depth 1-4 mm, width greater than 2 mm, at spacing 50 to 200 mm. R3 Grooves of depth 4-10 mm, width > 5 mm, at spacing 50 to 200 mm. R4 Grooves or undulations of depth greater than 10, width > 10mm, at spacing 50 to 200 mm. Parameters for defining shaft wall roughness (after Horvath et al., 1980 and Kodikara et al., 1992) Upper and lower bound guidelines for effective roughness adapted from (Seidel and Collingwood, 2001)
  • 9. Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 9 Factors related to drilled shaft geometry Unit side shear versus displacement for drilled shafts socket in rock with qu = 3 MPa (after Baycan, 1996)
  • 10. Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 10 Factors related to the load test method Comparison of typical Load-Displacement behavior four test procedures (adapted from Fellenius, 1975) 0 20 40 60 80 100 120 140 160 180 0 1 2 3 4 5 6 7 8 Load Displacement CRP Quick ML Cyclic
  • 11. Unit side shear resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 11 Reference 留 硫 C 1 Rosenberg and Jouneaux (1976) 0.34 0.51 1.05 2 Horvath (1978) 0.33 0.50 1.04 3 Horvath and Kenney (1979) lower bound 0.21 0.50 0.65 Horvath and Kenney (1979) upper bound 0.25 0.50 0.78 4 Meigh and Wolski (1979) 0.22 0.60 0.55 5 Reynolds and Kaderabek (1980) 0.30 1.00 0.30 6 Pells et al. (1980) R1, R2 & R3 0.40 0.50 1.26 Pells et al. (1980) R4 0.80 0.50 2.52 7 Williams et al. (1980) 0.44 0.37 1.85 8 Horvath (1982) smooth 0.20 0.50 0.63 9 Horvath (1982) roughness 0.30 0.50 0.95 10 Gupton and Logan (1984) 0.20 1.00 0.20 Reference 留 硫 C 11 Rowe and Armitage (1984) smooth 0.45 0.50 1.42 Rowe and Armitage (1984) roughness 0.60 0.50 1.89 12 Reese and O'Neill (1987) 0.15 1.00 0.15 13 Carter and Kulhawy (1988) 0.2 0.50 0.63 14 Toh et al. (1989) 0.25 1.00 0.25 15 Kulhawy and Phoon (1993) 0.35 0.50 1.10 16 O'Neill and Reese (1999) 0.21 0.50 0.66 17 Zhang and Einstein (1998) lower bound 0.20 0.50 0.63 Zhang and Einstein (1999) upper bound 0.40 0.50 1.26 18 Prakoso (2002) lower bound 0.20 0.50 0.63 Prakoso (2002) upper bound 0.32 0.50 1.00 19 Kulhawy et al. (2005) 0.32 0.50 1.00 20 Turner (2006) 0.32 0.50 1.00 Summary of relations between t and qu (expanded version from ONeill et al., 1996)
  • 12. Unit end bearing resistance Mayag端ez, Puerto Rico Thursday June 7, 2012 12 Design Method Teng (1962) [5-8] 1 Coates (1967) 3 1 Rowe and Armitage (1987) 2.7 1 Zhang and Einstein (1998) 4.5 1 ARGEMA (1992) [3-6.6] 0.5 Empirical relationships between and (expanded version from Zhang & Einstein, 1998) Between 10% - 20% (Williams et al., 1980; Carter & Kulhawy, 1988) A significant relative movement between concrete and rock is necessary to achieve the total end bearing resistance (Qb) Some methods proposed for predict (Qb) are based on elastic solutions and depend on the embedment ratio (L/B) and the rate of stiffness (Ec/Er) Theoretical base load transfer (adapted from Rowe and Armitage, 1987b) =
  • 13. Weak rock / IGMs definition Mayag端ez, Puerto Rico Thursday June 7, 2012 13 Weak rock Weathered and broken rock (BS, 8004) Indurated soil (Oliveira, 1993) Soft rock (Johnston, 1989) Intermediate geo-material IGM (FHWA, 1995) IGM strength classification based on qu versus (adapted from Kulhawy and Phoon, 1993)
  • 14. Summary Mayag端ez, Puerto Rico Thursday June 7, 2012 14 Demand of loads of great magnitude 1976 2006 Range of estimation to predict Qs 86% 93% The 27.5% geomorphology area of Puerto Rico is conformed fro three karst zones (North, South and disperse) $ versus capacity 0 5 10 15 20 25 30 10 30 50 70 90 110 130 150 max/Pa qu/Pa Rosenberg and Jouneaux (1976) Horvath (1978) Horvath and Kenney (1979) lower bound Horvath and Kenney (1979) upper bound Meigh and Wolski (1979) Reynolds and Kaderabek (1980) Pells et al. (1980) R1, R2 & R3 Pells et al. (1980) R4 Williams et al. (1980) Horvath (1982) smooth Horvath (1982) roughness Gupton and Logan (1984) Rowe and Armitage (1984) smooth Rowe and Armitage (1984) roughness Reese and O'Neill (1987) Carter and Kulhawy (1988) Toh et al. (1989) Kulhawy and Phoon (1993) O'Neill and Reese (1999) Zhang and Einstein (1998) lower bound Zhang and Einstein (1999) upper bound Prakoso (2002) lower bound Kulhawy et al. (2005) Turner (2006)
  • 15. Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 15 Location General location map of test site not to scale (adapted from www.mapsof.net 息 2012) Aerial image showing location of experimental farm La Monta単a (from Google Earth 息2012) Aerial images showing general location of test site (from Google Earth 息 2012)
  • 16. Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 16 Geology Geological map of Puerto Rico (adapted from Renken et al., 2002) Elevation view of the North Coast Belt of Puerto Rico (adapted from Renken et al., 2002) Ta
  • 17. Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 17 Engineering properties Drilled shafts load test and site investigation layout (not to scale) Thermo-gravimetric analyses (TGA) of Aymam坦n limestone
  • 18. Site Characterization Mayag端ez, Puerto Rico Thursday June 7, 2012 18 Boring log DS_A2 Drilled shafts load test and site investigation layout (not to scale) Stress-Strain diagram for Aymam坦n limestone (UCS) test
  • 19. Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 19 General test layout Layout of load test arrangement Setup and arrangement of axial compressive load test
  • 20. Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 20 Field test program Layout of load test arrangement 1 2 0 10 20 30 40 50 60 70 0 50 100 150 200 250 300 time(min) Load (kips) Duration of Load Test 0 5 10 15 20 25 30 0 50 100 150 200 250 300 time(sec) Load (kips) Duration of Load Test
  • 21. Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 21 Construction of drilled shafts Layout of load test arrangement 1 2 DS_LT 1 DS_LT 2 0 5 10 15 20 0.1 1 10 100 1000 Effectiveheightofroughness-r(mm) qu (Mpa) Upper Border Bottom Border DS_LT 1 DS_LT 2 DS_LT 1 Parameter Values Reference Roughness Classification R3 Pells et al (1980) Medium to high RF 0.20 Horvath et al (1980) Low to medium hm 4.67 mm Kodikara et al (1992) Medium isd 5.51 re 4.67 Seidel y Collingwood (2001) See Figure DS_LT 2 Parameter Values Reference Roughness Classification R3 Pells et al (1980) Medium to high RF 0.21 Horvath et al (1980) Low to medium hm 4.78 mm Kodikara et al (1992) Medium isd 5.20 re 4.78 Seidel y Collingwood (2001) See Figure Effective height roughness versus qu for drilled shafts DS_LT1 and DS_LT2 (after Seidel and Collingwood, 2001) Summary of roughness parameters for drilled shafts DS_LT 1 and DS_LT 2Summary of roughness parameters for drilled shafts DS_LT 1 and DS_LT 2
  • 22. Field test program Mayag端ez, Puerto Rico Thursday June 7, 2012 22 Construction of drilled shafts
  • 23. Results Mayag端ez, Puerto Rico Thursday June 7, 2012 23 DS_LT1 0.974 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0 50 100 150 200 250 300 Displacementoftoppile(in) Load (kips) 1 sequence 2 sequence 3 sequence Load versus displacement for the drilled shaft DS_LT 1 0 200 400 600 800 1,000 1,200 0 50 100 150 200 250 300 袖strain Load (kips) EGP1 (袖) level 46.25 in EGP2 (袖) level 34.35 in EGP3 (袖) level 21.75 in EGP4 (袖) level 9.75 in EGP5 (袖) level - 4.25 in Load applied versus strains for drilled shaft DS_LT 1
  • 24. Results Mayag端ez, Puerto Rico Thursday June 7, 2012 24 DS_LT2 Load versus displacement for the drilled shaft DS_LT 2 0.773 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0 50 100 150 200 250 300 Displacementoftoppile(in) Load (kips) 0 200 400 600 800 1,000 1,200 0 50 100 150 200 250 300 袖strain Load (kips) EGP1 (袖) level 49.5 in EGP2 (袖) level 36.5 in EGP3 (袖) level 23.25 in EGP4 (袖) level 9.5 in EGP5 (袖) level -4.5 in Load applied versus strain for drilled shaft DS_LT 2
  • 25. Results Mayag端ez, Puerto Rico Thursday June 7, 2012 25 250.56 12.85 -12 0 12 24 36 48 60 0 100 200 300 Depth(in) Load (kips) Q= 15 kips Q= 25 kips Q= 40 kips Q= 45 kips Q= 65 kips Q= 100 kips Q= 165 kips Q= 215 kips Q= 250 kips Qs max Qs min Load distributions for drilled shaft DS_LT 1 272.20 5.46 -12 0 12 24 36 48 60 0 100 200 300 Depth(in) Load (kips) Q= 10 kips Q= 25 kips Q= 35 kips Q= 45 kips Q= 65 kips Q= 100 kips Q= 150 kips Q= 200 kips Q= 230 kips Q= 250 kips Q= 270 kips Q max Q min Load distributions for drilled shaft DS_LT 2
  • 26. Results Mayag端ez, Puerto Rico Thursday June 7, 2012 26 Maximum skin friction mobilized for drilled shaft DS_LT 1 Maximum skin friction mobilized for drilled shaft DS_LT 2 0 10 20 30 40 50 0 200 400 600 Depth(in) Unit side shear resistance mobilized (psi) Q=20 kips Q=25 kips Q=45 kips Q= 67 kips Q= 100 kips Q= 165 kips Q= 215 kips Q= 250 kips 0 10 20 30 40 50 0 200 400 600 Depth(in) Unit side shear resistance mobilized (psi) Q= 272 kips Q= 200 kips Q= 150 kips Q= 100 kips Q= 75 kips Q= 50 kips Q= 25 kips Q= 10 kips
  • 27. Comparative prediction - measured Mayag端ez, Puerto Rico Thursday June 7, 2012 27 275 250 333.21 49.01 0 100 200 300 400 500 600 700 800 150 350 550 750 950 1150 1350 Drilledshaftloadcapacity-Qu(psi) Unconfined compressive strength - qu (psi) Carter and Kulhawy (1988) Pells et al. (1980) R4 Limestone DS_LT 2 (Q measured) DS_LT 1 (Q measured) Qu DS_LT 2 est Qu DS_LT 1 est Qtu e
  • 28. Conclusions Mayag端ez, Puerto Rico Thursday June 7, 2012 28 Shafts roughness index factor Shaft geometry - diameter and length Rate of load method Classification of limestone from the Aymam坦n formation in La Montana farm Pells et al. (1980). other correlations The behavior of the drilled shafts tested Future work La Montana farm
  • 29. Acknowledgments Family Geo-Cim Inc, Dywidag-Systems International, MS Drills, Structural Steel Manufacturing, Inc. Mr. A単eses and all the people which work in the La Monta単a farm Augusto Ortiz, Manuel Collazo Dr. Ricardo Ramos, Dr. Daniel Wendichansky, and Dr. Miguel Pando Friends PRSN Christa and Victor Finally, thanks Ana, Andr辿 & Mateo Puerto Rico Seismic Network (PRSN) January 17th, 2012 29
  • 30. Puerto Rico Seismic Network (PRSN) January 17th, 2012 30

Editor's Notes

  1. Mecanismos de transferencia de carga axial a compresion de fustes barrenados en roca caliza y porosa
  2. a) Carga total aplicada menor a la resistencia unitaria al corte, b) Carga aplicada aumenta pero aun menora a la resitencia ultima unitaria al corte, c) carga aplicada mayor, se alcanza la resistencia unitaria al corte ultima y se genera la reaccion de la punta del pilote. d) carga ultima del pilote es la suma de la resistencia ultima al corte y la resistencia ultima de la punta o base del pilote.
  3. En la medida en que se va aumentando la carga a compresion, la curva carga desplazamiento mostrara un comportamiento lineal al momento de alcanzar la resistencia unitaria al corte ultima, la curva ya no mostrara un comportamiento lineal y entrara en una zona de transision. Provocando un mayor desplazamiento con incrementos de carga menores hasta que ocurre un deslizamiento pleno donde la resistencia unitaria al corte ultima se ha sobre pasado.
  4. DS_LT1 carga mas lenta, menor carga para un desplazamiento igual que para una carga rapida DS_LT2 que requiere una carga mayor. Desplazamientos mayores para cargas mas lentas Desplazamientos menores para cargas mas rapidas.
  5. BS 8004 Roca fracturada o meteorizada Johnston 1989 roca blanda Oliveira 1993 suelo endurecido IGM 1995 Rango en psi [ ] Mpa [ ]
  6. Costo de drilled shafts por pie de profundidad vrs diametro Hormigon ($105/yrd3).
  7. Roca sedimentaria 23.5 millones de anos, era cenozoica terciaria (Ta), edad del mioceno temprano. 88% Ca,
  8. Porosidad 41.17%, relacion de vanos de .7, peso especifico seco 102 pcf,
  9. Carga maxima por pie de profundidad comparar con velocidad de aplicacion de carga.