HIGH CAPACITY ROCK ANCHORS IMPLEMENTATION OF QA/QC PROGRAMS. JULIO DIAMANTE, P.E.

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1 JULIO DIAMANTE, P.E.

2 In a broad sense, foundation engineering is the ART of selecting, designing, and constructing the elements that transfer the weight of a structure to the underlying soil or rock. Peck, Hanson and Thornburn Foundation Engineering, Page 1 December

3 We all know that art is not the truth, ART is a lie that make us realize the truth. Pablo Picasso Surrealist Artist 3

4 HCRA PROPOSED DEFINITION ARE POST-TENSIONED SYSTEMS USED TO TRANSFER VERY LARGE LOADS TO DEEP UNDERLYING ROCK FOUNDATIONS. DESIGN LOAD (DL) LENGTH SYSTEM CORROSION PROTECTION BONDING AGENT > 1500 Kips > 150 ft MULTI-STRAND CLASS I ENCAPSULATION REQUIRED CEMENTITIOUS GROUT INSTALLATION TIME MORE THAN A WEEK FOUNDATION USUALLY ROCK (RQD% > 80%) 4

5 HCRA APPLICATIONS BRIDGES PORT TERMINALS SLOPE STABILIZATION WIND MILLS OIL INDUSTRY (TLPs) POWER PLANTS TUNNELS GRAVITY DAM STABILIZATION 5

6 STRUCTURES ARE PRESTRESSED PRE-TENSIONING or POST-TENSIONING 6

7 POST-TENSIONING ROCK ANCHORS Recommendations for Pre-stressed Rock and Soil Anchors (The PTI Manual) was published by the PTI to provide guidance in the application of permanent and temporary pre-stressed rock and soil anchors utilizing high strength pre-stressing steel. 7

8 MULTI-STRAND HCRA INSTALLATION MULTI-STRAND ANCHOR POST-TENSION ANCHOR PERFORMANCE LOAD TEST 7 WIRE LOW RELAXATION STRAND ASTM A 416 BARE STRAND PRESTRESSING STEEL STRAND WITH SHEATH AND CORROSION INHIBITING COMPUND (GREASE, WAX or GEL) ROCK DRILLING INSTALLATION LONG TERM MONITORING CORRUGATED SHEATHING INSTALLATION TAIL LENGTH ANCHOR HEAD BEARING PLATE CONCRETE UNBOND LENGTH ` INDUCED COMPRESSIVE STRESSES ` BOND LENGTH ROCK FOUNDATION CONCRETE-ROCK BONDING STRENGTH 8

9 STABILIZATION OF GRAVITY DAMS ALL MODELS ARE WRONG, BUT SOME ARE USEFUL. G. Box and N. Draper, 1987 HOW TO INCREASE SLIDING RESISTANCE? ADD VERTICAL AND INCLINED FORCES Pv W W Pi μ f μ f f = f (W, μ) CHANGUINOLA DAM, PANAMA 9

10 STABILIZATION OF GRAVITY DAMS START FEA ANALYSIS TIE-DOWN UPSTREAM TIE-BACK DOWNSTREAM BL f ROCK FOUNDATION 10

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12 Water Test Video Inspection Alignment Survey Max. 5.5 gallons in 10 psi 12

13 IF HOLE WATER TEST FAILS If Vgrout < 120% Vtheor no need for additional water tests (PTI) 13

14 CORRUGATED SHEATHING INSPECTION RUN SHEATHING WATER TEST PRIOR AND AFTER TENDON INSTALLATION (2.25 GAL/10 MIN/10 PSI) CORRUGATED SHEATHING CENTRALIZERS CORRUGATED SHEATHING GROUT PIPES 14

15 ALWAYS PERFORM A TENDON INSPECTION PRIOR TO INSTALLATION ANCHOR HOLE OUTSIDE GROUTING PIPE CORRUGATED SHEATHING STRANDS INSIDE GROUTING PIPE 15

16 MULTI-STRAND HCRA INSTALLATION MULTI-STRAND ANCHOR POST-TENSION ANCHOR PERFORMANCE LOAD TEST 7 WIRE LOW RELAXATION STRAND ASTM A 416 BARE STRAND PRESTRESSING STEEL STRAND WITH SHEATH AND CORROSION INHIBITING COMPUND (GREASE, WAX or GEL) ROCK DRILLING INSTALLATION LONG TERM MONITORING CORRUGATED SHEATHING INSTALLATION TAIL LENGTH ANCHOR HEAD BEARING PLATE CONCRETE FREE LENGTH UNBOND LENGTH ` INDUCED COMPRESSIVE STRESSES ` BOND LENGTH ROCK FOUNDATION CONCRETE-ROCK BONDING STRENGTH 16

17 HYDRAULIC JACK CALIBRATION HCRA PERFORMANCE LOAD TEST LAB LC (Kips) JACK PRESSURE GAUGE (psi) REPRODUCED WITH PERMISSION OF DSI AMERICA JACK REPRODUCED WITH PERMISSION OF DRILL TECH AND SHORING 17

18 HCRA PERFORMANCE LOAD TEST ACCEPTANCE CRITERIA BY PTI ANCHOR REACHES TL CREEP < 0.04 ALIGNMENT LOAD PERFORMANCE LIFT OFF TEST ~ 1.10 DL LOAD TEST 5-25% DL DESIGN LOAD APPARENT LENGTH DL TEST LOAD 1.33 DL CREEP TEST (10 MIN) LOCK OFF 1.10 DL LIFT OFF TEST ~ (1.10 DL) ± 5% 18

19 QA/QC PROGRAMS - ADDITIONAL NOTES 10,000 kips load test REPRODUCED WITH PERMISSION OF CTL GROUP, IL 19

20 MULTI-STRAND HCRA INSTALLATION MULTI-STRAND ANCHOR POST-TENSION ANCHOR PERFORMANCE LOAD TEST 7 WIRE LOW RELAXATION STRAND ASTM A 416 BARE STRAND PRESTRESSING STEEL STRAND WITH SHEATH AND CORROSION INHIBITING COMPUND (GREASE, WAX or GEL) ROCK DRILLING INSTALLATION LONG TERM MONITORING CORRUGATED SHEATHING INSTALLATION TAIL LENGTH ANCHOR HEAD BEARING PLATE CONCRETE UNBOND LENGTH ` INDUCED COMPRESSIVE STRESSES ` BOND LENGTH ROCK FOUNDATION CONCRETE-ROCK BONDING STRENGTH 20

21 LONG TERM MONITORING : VIBRATING WIRE LOAD CELLS 2500 kips 6 VW LOAD CELL HYDRAULIC JACK CALIBRATIONS UP TO 3000 KIPS, UNIVERSITY OF ILLINOIS REPRODUCED WITH PERMISSION OF DR. PHILLIPS, UNIVERSITY OF ILLINOIS, IL 21

22 LONG TERM MONITORING : FIBER OPTIC STRAIN GAGES UP TO 5000 KIPS LEHIGH UNIVERSITY, PA RESISTANCE STRAIN GAGE LOAD 700 Kips µε 0 TENSION (+) STRAIN OPTICAL STRAIN GAGE OPTICAL TEMPERATURE GAGE µε COMPRESSION (-) REPRODUCED WITH PERMISSION OF CENG/MICRO N OPTICS REPRODUCED WITH PERMISSION OF CENG/MICRON OPTICS FIBER OPTIC STRAIN GAGE CALIBRATION Kips CF µε REPRODUCED WITH PERMISSION OF CENG/MICRON OPTICS (GINNA NPP) SHIM COMPRESSION 22

23 LONG TERM MONITORING : MAGNETIC PERMEABILITY DYNA FORCE BY DSI ELASTO-MAGNETIC SENSOR FORCE MONITORING DURING CONSTRUCTION DYNA FORCE SENSOR RETAINING WALL LONG-TERM AND REMOTE MONITORING MEASURES LOCK OFF TRANSFER LOAD AT THE BL SENSOR BOND LENGTH INSTALLATION AUTOMATED LOAD MONITORING CABLE STAY TESTING REPRODUCED WITH PERMISSION OF DSI AMERICA 23

24 2.5 IN (6.4 CM) SMART HCRA COMBINATION OF REMOTE LONG TERM MONITORING SYSTEMS WHAT S NEXT? FIRST GTECH WORK AWAY FROM HOME SMART DRILL RIGS ` FUTURE ROUGHNECKS DRILLING & ROCK SAMPLING 24

25 IMPLEMENTATION OF QA/QC PROGRAMS JULIO DIAMANTE, P.E. THANKS FOR YOUR TIME AKNOWLEDGMENT POST-TENSIONING INSTITUTE D&B CONSULTING ENGINEERS DSI AMERICA GEOKON MICRON OPTICS CERN CTL GROUP UNIVERSITY OF ILLINOIS 25