automated recording system for jack in pile-final recording s… · · 2015-11-19. learning...
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Automated Recording System for Jack In PileIr. Liew Shaw Shong
Geotechnical Automation & Innovation• Back Ground & Objectives
• Problem Statement
• Solutions & Future R&D
• Learning &Application of Multi‐Engineering Disciplines
• Case History
• Concluding Remarks
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation2
Pile Foundation SupportLoad Carrying Capacity & Safety Factor
Are these Loadings a Static or Dynamic Actions?
Settlement Performance & Stiffness Response
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation3
Static InjectionNewton’s 3rd Law : Action = Reaction
Proof Loaded by Kentledge Static Loading
Until Injection Refusal (Short term)
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation4
Jack In Piling SystemDead Weight Ballast
Self Service Crane
Power Pack
Hydraulic Gripping System
Hydraulic Injection System
Movable Bearing Sleepers
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation5
Jack In Piling SystemHydraulic Actuators (2 & 4 Concentric Pairs)
Hydraulic Gripping System
‐ Curvature of Gripping arch to fit pile diameter
‐ Contact area for gripping friction
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation6
Schematic
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation7
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation8
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation9
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation10
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation11
Kick‐Out of Pile Toe
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation12
Load (kN)
Settlement (mm)
Pile Heave
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaxation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement – Longer Holding Time
Erroneous Recording
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation13
Creeping Behaviour :
• Dissipation of excess pore pressure (Cohesive fine materials)
• High component of pile capacity on End Bearing on Stiff Fine Soils
• Imposed load near to Ultimate Resistance (Plastic deformation in Progressive Load Transfer of LoadPile)
Problem StatementInjection Obstruction (Boulders, shallow & intermittent hard layers) ‐ Preboring
Buckling in Prebored Hole & Toe Relaation –Backfilling/Grouting
Kick‐out (Pile flexural distress) – Pointed Pile Shoe
Pile Heave (Soil displacement) & Toe Relaxation ‐Rejacking
Creeping Settlement
Erroneous Recording ‐Automation
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation14
Pile Joint Welding
Carbon Footprint : Energy to install a Pile, E = F(x)dx
SolutionsReal‐time Monitoring System
Wire spring LVDT Penetration Decoder
Pressure transducers for Jacking Load Measurement & Flag of Pile Grip
LCD Panel
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation15
Advantages
• Continuous monitoring and recording of Jacking Load & Pile Penetration (Good record of jacking resistance rather than erroneous manual recording, pile jointing, etc )
• Criterion to either timely manually cease or automated Jacking on Sudden Reduction of Jacking Load
• Reduce the workload of jacking rig operator
• Prevent uncontrolled structural damage to pile resulting in the abandonment of original damaged jacked pile and more compensation piles and pilecap enlargement are needed
• Rejacking of under capacity pile to maximise usable capacity of piles at risky areas where pile damage is expected if jacking is not controlled
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation16
Pile ProductivityCooling Duration for Pile Joint Welding
Application of Anti‐Corrosion Paint
Investigation using Thermal Imaging Tool
Natural Cooling & Induced Air Flow Cooling
Flux Cored Arch Welding (FCAW) / Gas Metal Arch Welding (GMAW)
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation17
Flux Cored Arch Welding (FCAW) / Gas Metal Arch Welding (GMAW)
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation18
1)PILE INSTALLATION PROCEDUREChecklist:‐1) Rock head level (______m)2) 400mm ø spun pile Class B (Working Load =120 Tonne, Grade 80)3) Jacking Load =2 x WL = 2 x 120= 240 Tonne
START INSTALL THE PILE
PLOT GRAPH OF JACKING LOAD VS DEPTH
CHECK THE CHANGE IN LOAD‐DEPTH GRADIENT‐JACKING MUST BE STOPPEDAT 100%, 150% AND 200% WLAND AT 1M ABOVE ROCKHEAD TO VERIFY RECORDS
TERMINATE AT 2xWL. CHECK THE FLOW CHART OF TERMINATION CRITERIA
YES, WITH NORMAL CHANGE IF CHANGE IN GRADIENT OBSERVED
e.g. AT POINT C, SET TERMINATION LOAD TO 95% OF ONE READING LESS WHICH IS AT POINT B.
APPLY SET CRITERIA FOR DOWNGRADED TERMINATION LOAD
INSPECT IF PILE IS IN GOOD CONDITION (SEE STANDARD PROCEDURE)
NO, CONTINUE JACKING
CONSULT ENGINEER TO CHECK IF DOWNGRADING IS REQUIRED
YES, WITH ABNORMAL CHANGE
TERMINATION AT 2x WL
2) FLOW CHART OF TERMINATION CRITERIA
Once reach intended load
1st SetJack: 2 x WL or Downgraded LoadHold: 20 SecondsCheck Settlement : <2mmRelease Load
2nd SetJack: 2 x WL or Downgraded LoadHold: 20 SecondsCheck Settlement : <2mmRelease Load
3rd SetJack: 2 x WL or Downgraded LoadHold: 20 SecondsCheck Settlement : <2mmRelease Load
PASS
NOT OKOK
OK
FOR EACH SET STAGE
1) Before apply load4) Release Load
3) Hold 20 Seconds2) Apply 200% WL
<2mm
Wait 3 minutes
Wait 3 minutes
REFER TO THE PROCEDURE TO OBSERVE AND RECORD PILE HEAVING AFTER INSTALLATION
Change in Gradient
BA
C
*Change in Gradient (A‐B, B‐C)
95% OF LOAD AT POINT B
NORMAL ABNORMAL
3) STANDARD PROCEDURE FOR PILE INSPECTION OF DOWNGRADED PILES TO INSPECT POSSIBLE SIGNS OF DAMAGE
SHINE A TORCH‐LIGHT THAT IS TIED TO A MEASURING TAPE THORUGH THE CENTRAL ANNULUS OF SPUN PILE.
PILE CONSIDERED ACCEPTABLE ‐MEASURE THE DEPTH OF ‘DEFECTS’. ‐USE CAMERA FOR VIDEO RECORDING. (IFCONDITION PERMITTED)
YESNO
INSPECT THE LOCATION OF ‘DEFECTS’
RECORD THE FOLLOWING INFORMATION:‐I) Type and size of spun pileII) Jacking pressureIII) Length of pile installed IV) Number of pile sections and its individual lengthsV) Depth of defectsVI) Direction and orientation of the defects or tilting direction of
damaged pile segmentVII) Any observation of water seepages, rise of water or soil debris
inside spun pileVIII) Photograph records of internal an external pile conditionsIX) Possible mechanism of breakage
REFER TO THE PROCEDURE TO OBSERVE AND RECORD POSSIBLE PILE HEAVING AFTER INSTALLATION
PILE TERMINATED AT DOWNGRADED LOAD
ENGINEER TO ASSESS ACCEPTABILITY OF PILES
4) PROCEDURE TO RECORD POSSIBLE PILE HEAVING AFTER PILE INSTALLATION
CHECK THE PRECISE LEVELLING OF PREVIOUSLY INSTALLED PILES TO DETERMINE ANY HEAVING OF PILE OBSERVED
INDICATE THE PRECISE LEVEL OF THE SPUN PILE
INSTALLATION OF SPUN PILE COMPLETED.
LEVELLING STAFF SHALL BE LOCATED OVER THE TOP SURFACE OF CUT PILE
LEVEL
CUT OFF
AFTER THE LAST PILE WITHIN THE SAME GROUP HAS BEEN INSTALLED
Future R&D
Real‐Time Monitoring System• Laser Distance Ranging Measurement
• Independent Precise Level Measurement (for Rate of Pile Penetration at Termination)
• Higher scanning frequency data logger for timely response & pile creep measurement during load holding for pile termination and MLT
• Automation jacking control regime to prevent structural damage to piles
Jack‐In Hydraulic System• Pressure Control Hydraulic System (against existing constant fluid discharge pump system)• Pressure regulatory chamber (Air‐Fluid Phases)• Variable relief valve and back flow system• Low flow & high pressure pump
• Load Holding for MLT
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation24
Automation Control System
• Operational Criteria to Control Jacking• Rate of Jacking penetration• Threshold of Jacking Load Reduction• Rejacking Load for Downgrading Pile Capacity
Future R&D
Laser Detection & Ranging System Jack‐In Hydraulic System
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation25
http://www.dynexhydraulics.com/cbpump.htm
Learning &Application of Multi‐Engineering Disciplines• Geotechnical & Structural Engineering : Knowledge in Problem Identification and Solution
• Electronic & Mechanical Sensors : Means to achieving Measurements in Jacking Operation
• Hydraulic System in Mechanical Engineering : To expand Capability of Jacking Operation to performing Maintain Load Test
• System Control : Criteria Management for Potential Automation Control
• Psychology : Friendly Interaction between Human & Machine
July 22, 2012 Footer text here26
Case History• Site Area : 2.5 Acres
• 2 Blocks of 18‐Storey Towers (250 Units)
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation27
Ground Conditions• Mine Tailing Materials of Clayey SILT/Silty SAND
• SPT‐N : 5 to 20
• Limestone Bedrock : 16 to 40m bgl
• Groundwater : 3m bgl
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation28
Compliance Foundation Design• Bored piles and spun piles, with bored piles used at locations with large loads and where there are cavities
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation29
Alternative Foundation Design
• Key Objectives•Optimise Cost•Complete Foundation Construction in 100 days
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation30
Alternative Foundation Design• Change all Bored Piles to Class B Jack‐in Spun Piles
• Simplify Construction Works• Less Congestion on Site & Noise Pollution• Reduce Mobilisation Cost• Proof Loading every Piles
• Remove Pointed Pile Shoe & Open Ended• Less Lateral Soil Displacement• Allow Installation of Underpinning Micropile if needed
• Reduce Type of Spun Pile Sizes• Only 400mm & 500mm Spun Piles for Better Efficiency• Streamline the Jacking Operation
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation31
Pile Injection Trial Tests
PLT1
• Without instrumentation
• To verify maximum pile capacity
• The jacking load during installation was recorded manually at this stage as the real‐time monitoring device was not ready for the test pile installation.
PLT2
• with instrumentation using the Global Strain Extensometer (Glostrext) system
• to measure the movement of pile segments for global axial strain, load transfer behavior during jacking and also interpreted locked‐in/residual stress in the pile after the unloading cycle
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation32
Findings from PLT1 & PLT2
• Pile geotechnical capacity achieved for a 500mm diameter pile is much less than its structural capacity as in PLT2
• Existing weak ground condition does not permit jacking rig to take excessive reaction weight
• Hence, a smaller 400mm diameter pile with working load of 1,200kN was proposed
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation33
Final Alternative Pile Design
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation34
Pile Layout
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation35
Construction –Timing
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation36
Construction – Reduced Cooling Time After Welding• Thermal imaging to compare the rate of reduction in temperature of a naturally ventilated weld compared to one with forced ventilation using blower fan
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation37
Construction – Reduced Cooling Time After Welding• Cooling time reduced from 30min to 5min
• Production rate increased from 4 to 7 piles / rig / day
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation38
Daily Piling Production
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation39
Review of As‐built Statistics• 336 piles with capacities downgraded, out of which 305 piles have capacities > 2/3 original capacities
• 96 piles (8%) added to compensate for downgraded piles
• Pile wastages ~ 10%
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation40
Conclusions & Recommendations of Case Study• Case study on successful implementation of jack‐in pile system in limestone geology for two 18 storeys tower blocks
• Use of real‐time monitoring during jacking operation has enabled higher utilization factor and minimize risk of overstressing the piles
• Shorter cooling period for welding
• Achieve both Time & Cost Savings
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation41
Final Concluding Remarks• Technology advancement is possible if engineer is able to procure and practise a multi‐disciplinary knowledge. i.e. based on fundamental principle of mechanics & physics.
• Innovations : Use of ICT & Technology for Rapid Feedback Control in Automation to attain High Efficiency & Effectiveness of Construction
• Improvements : Construction Methodology, Materials, Workmanship
• Benefits : Faster, Less Wastage, Greener Construction, Better Assurance in Performance, Better Cost Economics, Less Human Errors
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation42
Engineering Process CycleStep 1 Design
Objectives
Step 2Problem
Identification
Step 3Option
Exploration
Step 4Execution of Solution
Step 5Performance Feedback
July 22, 2012 2‐Day Seminar on Advancement in Ground Investigation and Geotechnical Instrumentation43
Thank You