Jack-in Piling Environmental Friendly Piling System

Transcription

1 Jack-in Piling Environmental Friendly Piling System Part 1 - Chris Loh 7 Nov 12 CSC HOLDINGS LIMITED

2 Gracious Piling Environmental Friendly Low Noise No Vibration Jack-in Piling

3 How Many Decibels? Permissible Leq 75dB (12 hours) within 15m

4 How Far Have We Gone Since 24? length of piles installed Singapore To Jakarta

5 Contents Method of Jack-in Piling System Installation Process Machine Movement and Installation Process (Video) Advantages of Jack-in Piling Mitigating Measures Jack-in Piling Machines Completed High Rise Buildings Projects Some Valued Clients To Conclude

6 Method of Jack-in Piling System CSC HOLDINGS LIMITED

7 Method of Jack-in Piling System A modern technique by which pre-formed piles (e.g. Prestressed Spun Piles, Precast RC Piles, H-Piles, Steel Pipe Piles) are hydraulically jacked into the ground as displacement piles

8 Installation Process CSC HOLDINGS LIMITED

9 Installation Process Pile is jacked into the ground with a jack-in force adjusted in steps up to between 1.8 times times working load Jacking will continue until practical refusal where jack-in force is released and reapplied twice Downward movement of the pile between the two cycles is then measured and checked against the set criteria

10 Machine Movement and Installation Process (Video) CSC HOLDINGS LIMITED

11 Machine Movement (Video)

12 Installation Process (Video)

13 Advantages of Jack-in Piling CSC HOLDINGS LIMITED

14 Advantages of Jack-in Piling Environmental Friendly - Low Noise - Vibration Free - Minimal Spoils Disposal Able to achieve Good Verticality Lower Risk of machine toppling as compared with conventional leader type machines Every pile is jacked up to between 1.8 times times working load

15 Mitigating Measures CSC HOLDINGS LIMITED

16 Mitigating Measures Relief Boring Pre-Boring at Piling Point

17 Jack-in Piling Machines CSC HOLDINGS LIMITED

18 Jack-in Piling Machines Low Capacity Machines - 1 to 13 tons

19 Jack-in Piling Machines Medium Capacity Machines - 24 to 42 tons

20 Jack-in Piling Machines High Capacity Machines - 6 to 8 tons

21 Completed High Rise Building Projects CSC HOLDINGS LIMITED

22 Completed High Rise Building Projects Livia Condominium 17 Storey 151 RC Piles & Spun Piles RC Piles 25mm, 3mm, 35mm and 4mm Spun Piles 5mm and 6mm Piles Capacity 6tons, 85tons, 1tons, 16tons, 125tons and 17tons

23 Completed High Rise Building Projects Twin Waterfalls 17 Storey 15 Spun Piles Spun Piles 4mm, 5mm and 6mm Piles Capacity 1tons, 15tons and 215tons

24 Completed High Rise Building Projects Austville Residences 18 Storey 115 Spun Piles RC Piles 25mm Spun Piles 5mm and 6mm Piles Capacity 13tons, 187tons and 25tons

25 Completed High Rise Building Projects AMK Street 52 3 Storey 1293 Spun Piles Spun Piles 4mm, 5mm and 6mm Piles Capacity 118tons, 169tons and 231tons

26 Some Valued Clients CSC HOLDINGS LIMITED

27 Some Valued Clients

28 To Conclude Environmental Friendly Suitable for all types of Pre-formed piles Proven to be viable foundation system for high rise buildings Piles are load tested during installation

29 Thank You CSC HOLDINGS LIMITED

30 Jack-in Piling Environmental Friendly Piling System Part 2 Gwee Boon Hong 7 Nov 212 CSC HOLDINGS LIMITED

31 Contents. DESIGN CONSIDERATIONS DESIGN PARAMETERS EVALUATION BASED ON INSTRUMENTATION RESULTS (Case Study : Old Alluvium Formation) JACK-IN PILE PERFORMANCE USING DIFFERENT JACK-IN FORCE DURING INSTALLATION (Case Study : Tuas South Avenue - Jurong Formation)

32 JACK-IN PILING DESIGN CONSIDERATIONS

33 Jack-in Pile Design Structural Considerations Qa =.25 (fcu fpe) * Ac Qa : Allowable structural axial capacity fcu : Compressive strength of concrete at 28 days fpe : Effective prestress in concrete Ac : Cross-sectional area of concrete Geotechnical Considerations Ultimate geotechnical capacity is determined by : Static formula on the basis of soil test Termination criteria using resistance measured during pile installation Verify performance of piles designed by above methods using static load test For quality control purpose, PDA and PIT are also carried out

34 Design Parameters In Accordance with CP4:23 Ultimate geotechnical axial capacity Qu = fs x As + qb x Ab Shaft Resistance : fs = Ks.N; Ks = 2 to 5 ; (limiting to 2kPa) Base Resistance: qb= Kb.4.N; Kb = 6 to 9 ; (limiting to 18,kPa for soil) For rock, qb = lesser of strength of pile material and unconfined compressive strength of rock Factor of Safety : Shaft Resistance = 2.5 Base Resistance = 2.5 Ks and Kb are related to the characteristics of soil & method of installation Higher value of Ks and Kb may be adopted if substantiated by sufficient instrumented load test in similar soil condition

35 Set / Termination Criteria Wide variations in termination ( set ) criteria for jacked piles Min jacked force = K x design working load (K varies between 1.8 to 2.5) Holding time = 3~6 seconds Max allowable settlement of 2mm for 2 or more consecutive cycles In Singapore context, termination criteria using min jacked force of 2 x WL and set criteria of 2mm between two jack cycles is commonly adopted Final acceptance criteria for the installed piles need to be verified by static pile load test

36 CASE STUDY 1 DESIGN PARAMETERS EVALUTION BASED ON INSTRUMENTATION RESULTS

37 Case Study 1 - Punggol View Pri Sch (Old Alluvium) 2 4 Unit Shaft Resistance (kpa) Actual Back Analysis Ultimate Pile Capacity (kn) CS 2-5 Unit End Bearing (kpa) MS JIF=2.1xWL 443 (2.1xWL) SPT-N Design Pile did not fail at 3xWL Depth (m) SM Design SM SF>2.5 CS MS 1m difference in pile length = $$ SM q (Spun Pile diam. 6mm) q fs -6 q qb q F.O.S Qb - Design Geotechnical Capacity q -6 Qs - Design Structural Capacity = 21 kn = Ks.N, Ks = 2. to-62.5 (limited to 12 kpa) = 4.N.Kb Kb = 5 (limited to 75 kpa ) -65 = Qult - Design -6 JIF Qult - Back Analysis (Based on Ins Result)

38 Load Distribution CS MS SM 1177 SM SM 4 4 SPT 1 MS 28 MS Force Reading CS CS SM 4.7 Depth (m) Depth (m) SM D ep th (m ) CS MS Ks (fs/nav) fs (kpa) Loads (kn) Soil Layer Layer 59 1 SM 5 Low unit end bearing (152 kpa), Not fully mobilized fs 45 SPT Soil Layer Layer 5 CP4 Ks = 2N Average Ks = 4.4N CP4 Ks = 5N

39 Load Settlement Curve 8 Cycle-1 Cycle-2 Cycle ; 634 Load at Top (kn) ; ; Settlement at Pile Head (mm) 25 3

40 Displacement Vs Mobilized Resistance 2 2-6m End Bearing 6-12m 12-18m 18-24m m m m 1 5 Unit End Bearing (kpa) Unit Shaft Resistance (kpa) m Displacement (mm) Displacement (mm) Max unit shaft friction is mobilized at average pile displacement between soil stratum of 12mm or 2% of pile diameter. Mobilized unit end bearing was 152 kpa at pile toe displacement of 5.89mm or.9% of pile diameter.

41 Design Parameters Evaluation, Ks & Kb Assumed Ks 2 to 2.5 Kb 5 Measured kpa CP-4 2 to 5 2 kpa kpa ** 6 to 9 18 kpa ** Not fully mobilized

42 Mobilized Shaft Resistance (Old Alluvium) 45 Non-displacement Pile (NDP) 4 Displacement Pile (DP) 35 Unit Shaft Resistance (kpa) CP-4 Ks= 5N 3 CP-4 Ks=3N 25 2 CP-4 Ks=2N 15 CP-4 Ks=1.5N N-SPT Compilation of ULT (Instrumented) results from different piling systems within Punggol sites

43 CASE STUDY 2 EFFECT OF JACK-IN FORCE ON JACK-IN PILE PERFORMANCE AT TUAS SOUTH AVENUE - In collaboration with NUS (29) -

44 Pile & Instrumentation Layout Plan m (25D) TP2 CPT1 CPT1b CPT3a CPT2a CPT1a CPT3 CPT2 CPT1 CPT1b CPT1a CPT2 CPT2a CPT3 TP3 P1' 3 3 CPT3a 3 CPT4a CPT3a CPT4 CPT1, CPT1a, CPT1b, m CPT2a (14 D) CPT1a CPT1b CPT3 CPT2 CPT1 TP1 8.4 m D 4 1 ( ) : 2r (.6m) from center of spun pile CPT2, CPT2a, : 3r (.9m) from center of spun pile Before pile installation CPT3, CPT3a, : 5r (1.5m) from center of spun pile After pile installation CPT4, CPT4a After load test ; 1r (3.m) from center of spun pile

45 Soil Stratigraphy TP2 (JIF = 2xWL=586kN) 12m 4m TP1 (JIF=1.5xWL=4395kN) FILL (Loose to Medium Dense SAND) SPT-N of 5 to 12 KALLANG FORMATION (Very Soft to Soft Marine CLAY) SPT-N of 2 to 4 Residual Soil S VI (Stiff to Very Stiff Sandy CLAY) JURONG FORMATION 4m SPT-N of 1 to 2 1m Completely Weathered Siltstone/Sandstone S V (Stiff to Very Stiff Sandy CLAY) JURONG FORMATION SPT-N of 2 to m TP3 (JIF=2.25xWL=6592.5kN) 28.7m 31.7m JURONG FORMATION, Completely Weathered Siltstone/Sandstone S V (Hard Sandy CLAY, N>6)

46 Installation Record TP1 (1.5xWL=4395kN) Jack-In Force (kn) Depth (m) TP-2 CS (S-V) TP-3 CS (S-V) 19 set at 28.7m CS (S-V) MS (S-V) TP MS (S-V) MS (S-V) MS (S-V) MS (S-V) 25 3 CS (S-VI) CS (S-VI) 28-2 marine CLAY m arine CLAY 4 MS (S-VI) m arine CLAY 6 SM (Fill) SM (Fill) SM (Fill) TP3 (2.25xWL=6592.5kN) TP2 (2xWL=586kN) set at 29.9m set at 31.7m

47 Test program and Test Arrangement Kentledge reaction system (TP1 and TP3) Jack-in rig counter-weight reaction system (TP2)

48 Load Test Results Load LoadSettlement SettlementCurve Curve(Combine (CombinePlot) Plot) 2.5xWL (7325 kn) 1 1 TP1=29.9mm TP2=26.mm 9 9 TP3=26.5mm 98.24mm 98.24mm 8 8 (at 2.99xWL (At 2.99xWL = 8762kN) = 8762kN) 85.9mm Load at at Top Top (kn) (kn) Load mm (at 2.62xWL (At 2.62xWL = 769kN) = 769kN) 6 6 2xWL (586 kn) 5 5 TP1=18.8mm TP1' TP1' TP2=18.3mm 4 4 TP2 TP2 TP3=18.mm 3 3 1xWL (293 kn) TP3 TP3 TP1=7.5mm 2 2 TP2=6.2mm 1 1 Allowable Allowable Settlement Settlement (CP4) (CP4) TP3=7.4mm Settlement Settlementat attop Top(mm) (mm)

49 JIF, Qtot, Qs, and Qb 1 Qtot Qtot Qtot* (kn) (JIF) 593 (JIF) Force (JIF) Qtot 4475 Qs Qb TP1', L=28.7m (Failure test) TP2*, L=29.9m TP3, L=31.7m (Non failure test) (Failure test)

50 Unit Shaft Resistance Vs Displacement Lev A to Lev B Lev B to Lev C 25 Le v A to Lev B ( 1.4 m t o 6.4 m ) N - a ve = TP1 TP1' N - av etp1' = 1 Le v A t o Le v BN -(av1.4 m Lev A t o Le v B e = 11 ( 1.2m to t8o. 4 56m.4m ) ) N - a v etp3 = 9 Le v A t o Le v B ( 1.2 m t o m ) N - a v e = 11 TP2 TP2 TP3 TP3 1 N -a v e = 7 Le v B t o Le v C ( 6.4m t o 14.9 m ) N - a v e = 1 Le v C ( 6.45 m t o m) 25 TP2 Le v B t o Le v C t o) (6.4 5 Lev m t o 1B 4.2m Le v B t o Lev C Le v B t o Le v C -a v e ( 6.4m t o 14.9N m) 2 TP1' TP2 N - a v e = 1 =5 TP2 TP2 TP3 ( 8.4 5m t o m ) Le v B t o Lev C ( 8.4 5m t o m ) 15 N - a ve = TP3 TP N -a ve = 25 TP1' 1 N - av e = 16 TP N -ave = 25 Le v D t o Le v E ( 2.9 m t o m ) N -ave = 29 Le v D t o Le v E ( m t o m ) N - a v e = 16 TP1 TP1' TP2 TP2 TP3 TP3 TP3 TP Lev F to Lev G 25 2 Le v E to Le v F (2 3.2 m to 2 6.2m ) N -a v e = 2 4 Le v E to Le v F (2 4.4 m to 2 7.4m ) N -a v e = 3 Le v E to Le v F (2 8.2 m to 2 9.2m ) N - a ve = 19 TP1' TP2 TP Lev F to Lev G (2 6.2 m to m ) N -a v e = 3 5 Lev F to Lev G (2 7.4 m to m ) N -a v e = 3 5 TP2 Lev F to Lev G ( m t o m) N -a v e = 2 9 TP3 TP1' Displacement (mm) Displacement (mm) Displacement (mm) Displacement (mm) Le v D t o Le v E ( 19.7 m t o m ) 1 N -ave = 24 3 TP2 TP2 TP3 Displacement (mm) Displacement (mm) 5 TP3 = 24 1 UnitShaft Shaft Resistance (kpa) (kpa) Unit Resistance Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) 2 Lev D to Lev E ( 22.7m t o 28.2 m) Le v C t o Le v D ( m t o m ) Lev E to Lev F 25 TP2 N -ave = 24 ( m to 22.7 m ) N -a ve = 29 Le v C t o Le v D ( 14.9 m t o 2.9 m) Le v C t o Le v D N -a v e 2 TP1' N -a v e = 24 Displacement (mm) Displacement (mm) Lev D to Lev E Lev D to Lev E ( 2.9m t o 24.4 m) Le v C t o Le v D ( 14.9 m to 2.9 m ) 1 Displacement(mm) (mm) Displacement Lev D to Lev E ( 19.7 m to 23.2m ) TP1 N - a v e =TP1' 11 ( 14.2 m t o 19.7 m ) U nit Shaft R esistan ce (kpa) Le v C t o Le v D N - av e = 11 t om) Le v D ( 14 Le.2 mvt oc19.7 TP1 N - a vetp1' = 7 ShaftResistance Resistance (kpa) UnitUnit Shaft (kpa) N - a ve = 1 Le v B ( 1.7 m t o m ) Unit Shaft Resistance (kpa) Le v A t o Lev B ( 1.7Le m to.4 5 tmo ) v 6A 5 Unit Shaft Resistance (kpa) Lev C to Lev D 3 Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) 3 Le v E t o Le v F ( m t o m ) N -ave = 24 Le v E t o Le v F ( m t o m ) N -ave = 3 Le v E t o Le v F ( m t o m ) N - a v e = Displacement (mm) Displacement (mm) TP1 TP1' TP2 TP2 TP3 TP3 Lev F t o Lev G ( m t o m ) N - a ve = 3 5 Lev F t o Lev G ( m t o m ) N - a ve = 3 5 Lev F t o Lev G ( m t o m ) N - a ve = 2 9 TP1' TP2 TP3

51 Mobilized Shaft Resistance & End Bearing (Jurong Formation) 1 25 CP-4 Ks= 5N TP2 225 TP1 9 8 UnitU nend it En dbearing B earin g (kpa) (kpa) Unit Shaft Resistance (kpa) Unit Shaft Resistance (kpa) TP3 125 CP-4 Ks= 2N TP1' TP TP N-SPT SPT-N SPT-N Base Settlement (mm) (mm) PilePile Base Settlement Combined Plot TP1, TP2 and TP

52 Preload Effect 23 Rankine Lecture (Prof M.F. Randolph) Bored Pile No residual pressure at pile base during installation End-bearing could only be mobilized at relatively large displacement Jack-In Pile Significant residual pressure at pile base during installation (higher than driven pile) Higher end bearing could be mobilized at small displacement Bored pile Jack-in pile

53 Conclusions (1) Instrumented load tests have verified that : Qu of pile > Calculated Qu adopted from driven pile Qu of pile > JIF Piles installed by JIF of 1.5~2.25 x WL have adequate Qu & settlement within allowable criteria. Qu of Jack-in pile is a function of JIF and increases as JIF increases. All 3 test piles showed similar load-settlement behaviour up to 2xWL. Higher JIF could result in higher Qu but the use of JIF 1.5xWL is enough to ensure satisfactory pile performance up to 2xWL.

54 Conclusions (2) JIF > 2xWL could be better but may not be necessarily needed. An appropriate JIF shall be established with the use of static load test. Subsequently all piles could be installed using this termination criteria. Jack-in pile installation results in a preloaded pile toe condition, hence better displacement performance. More future research would help to provide accurate design in the use of jack-in pile.

55 THANK YOU! CSC HOLDINGS LIMITED

56 Q & A CSC HOLDINGS LIMITED