Lizzi Lecture Performance of Seismic Retrofits with High Capacity Micropiles. Jiro Fukui. Public Works Research Institute, Japan

Transcription

1 Lizzi Lecture 2006 Performance of Seismic Retrofits with High Capacity Micropiles Jiro Fukui Public Works Research Institute, Japan 1

2 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 2

3 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 3

4 Application example past in Japan Slope Stabilization Tunnel leg reinforcement 4

5 Capping Beam Concrete Micropiles Slope stabilization 5

6 Slope stabilization 6

7 oundation of bservatory Shield Tunnel Micropile Underpinning of existing foundations 7

8 Hyogoken-nanbu EQ,

9 Cracks on the cast-in-place concrete pile 9

10 Fall down of superstructure (Nishinomiya Br.) 10

11 Existing Pile Additional Pile Additional pile method 11

12 Construction procedure of additional pile method 12

13 Existing girder 13

14 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 14

15 Joint Research on the Development of Seismic Retrofit Method for the Existing Bridge Foundation Purpose : Development of new seismic retrofit method Establishment of design & construction manual Research Period :

16 Utilization of micropile for seismic retrofit of foundation (USA) 16

17 17

18 Retrofit method for existing bridge foundation by using micropiles Execution at narrow Working Area Small Enlargement of Footing & Small Excavation Original Footing Enlarged Footing Original Pile Micropile 18

19 Content of Joint research Loading test of High Capacity Micropile (vertical, horizontal) Horizontal loading test of group piles(existing piles & micropiles) Shaking table test of group piles Centrifuge loading test of group piles Analysis for group piles (simulation for the horizontal loading tests) Loading test of a connection part of pile head and footing Examination of design method for group piles Numerical analysis considering finite deformation of piles Examination of quality control & quality assurance by integrity test Design and Construction Manual 19

20 Content of Joint research Loading test of High Capacity Micropile (vertical, horizontal) Horizontal loading test of group piles(existing piles & micropiles) Shaking table test of group piles Centrifuge loading test of group piles Analysis for group piles (simulation for the horizontal loading tests) Loading test of a connection part of pile head and footing Examination of design method for group piles Numerical analysis considering finite deformation of piles Examination of quality control & quality assurance by integrity test Design and Construction Manual 20

21 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 21

22 max.φ300mm max.φ300mm max.φ300mm Deformed Bar Steel Pipe Soft Stratum Steel Casing Pipe Bearing Stratum Deformed Bar Grout Grout Grout (a)example of Deformed Bar Reinforcement (b)example of Steel Pipe Reinforcement (c)high capacity Micro Pile General form of Micropiles 22

23 Cases of Horizontal Loading Tests Case Number of Piles Spacing between Existing Piles Center and Micropiles Center (mm) Inclination Angle of Micropiles ( ) 1 Single Existing Pile Single Micropile Existing Piles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles

24 Case 1 Case 2 24

25 Case 3 25

26 Cases of Horizontal Loading Tests Case Number of Piles Spacing between Existing Piles Center and Micropiles Center (mm) Inclination Angle of Micropiles ( ) 1 Single Existing Pile Single Micropile Existing Piles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles Existing Piles and 6 Micropiles

27 Rear Front Existing Pile Micropile Loading Direction Arrangement of piles (Case 4-7) 27

28 Case 4 Case 5 28

29 Case 6 Case 7 29

30 Dimensions of Piles Diameter (mm) Thickness (mm) Sectional Area (cm 2 ) Moment of Inertia (cm 4 ) Existing Pile Micropile

31 Jack Steel Bar Footing Loading Test for Case 3 31

32 Load (kn) Case1 Case2 Case3 Case4 Case5 Case6 Case Deflection (mm) 32

33 Bending Moment (KN-m) Bending Moment (KN-m) Depth (cm) -200 Existing pile Micropile Case 3 Front Pile Case 3 Rear Pile Case 4 Front Pile Case 4 Rear Pile Case 4 Front Pile Case 4 Rear Pile

34 Case 4 Front Analysis Existing Pile Shear Force (kn) Rear Load (kn) Distribution of Shear Force Analysis Front Rear Micropile 34

35 Horizontal Ground Reaction (KN/ 2 ) C ase3 (G.L.-0.27m ) C ase3 (G.L.-0.57m ) C ase3 (G.L.-0.87m ) C ase4 (G.L.-0.27m ) C ase4 (G.L.-0.57m ) C ase4 (G.L.-0.87m ) Displacem ent of Pile (cm ) Horizontal ground reaction - Displacement Curve 35

36 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 36

37 To Study the Design Method of Group Piles with Different Diameter Piles. Simulation Analyses for Loading Tests by Ductility Design Method P , Ground Properties Flexural Rigidity of Piles 4,400Non-Linear Model

38 Model of Transverse Resistance of Ground Ground Reaction (N/m 2 ) p HU Upper Limit of Ground Reaction tan -1 k HE 0 Displacement (m) 38

39 Transverse Resistance Characteristics of Ground k HE = a k b k k H p HU = a p b p p U a k, a p : Correction Factors of a Single Pile b k, b p : Correction Factors of Group Piles To consider the group effects a k b k = 1 a p (Cray Ground) = 1.0 a p b p (Sandy Ground) = S/D ( 3) To consider the group effects of trailing piles 39

40 210 Load (kn) C ase3 Test C ase3 A nalysis C ase4 Test C ase4 A nalysis C ase5 Test C ase5 A nalysis C ase6 Test C ase6 A nalysis Displacem ent of Footing (mm) Load Displacement Curve 40

41 Bending Moment of Existing Piles in Case 3 and Case 4 B ending M om ent (kn m ) Bending M om ent (kn m ) Ground Level (cm Case Case 4 Test Result on Front Pile Test Result on Rear Pile Analysis R esult on Front Pile Analysis R esult on Rear Pile Ground Level (cm Test Result on Front Pile Test Result on Rear Pile Analysis Result 41

42 Bending Moment on Micropiles in Case 4 Bending M om ent (kn m ) Ground Level (cm Test Result on Front Pile Test Result on Rear Pile Analysis R esult on Front Pile Analysis R esult on Rear Pile 42

43 2 Horizontal Ground Reaction (kn/ ) Case 4 Test Result on Front Pile Test Result on R ear Pile M odelu sed in Analysis Depth;G.L.-0.57m Displacem ent of Pile (cm ) Horizontal ground reaction - Displacement Curve 43

44 Summaries of horizontal loading tests & analysis Results of horizontal loading tests Micropiles have a large reinforcement for existing foundation. Spacing between existing pile and micropile has little effect on reinforcement. Inclination of micropiles increase horizontal resistance of existing foundation. Results of simulation analyses Ductility design method for new foundation is available to retrofitting design with some modification. 44

45 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 45

46 Shear soil container 46

47 Properties of sand Physical properties 100 Density of soil particle ρs g/cm 3 Gravel content 0% Sand content % Silt content 0.00% Grin size distribution Clay content 0.00% Uniformity coefficient 2.31 Curvature coefficient 1.03 Maximum dry density ρd max g/cm 3 Minimum dry density ρd min g/cm 3 Street mass percentage(%) Grain diameter (mm) Gradation curve of the Hamaoka sand 47

48 φ = φ Models of reinforcing piles (m icropiles) Models of reinforcing piles (m icropiles) Models of existing piles Models of existing piles Models of existing piles 15 Existing pile Existing pile with micropile (vertical) Existing pile with micropile (inclined) Outline of the model 48

49 A3 L8 L1 A2 L9 A11 A4 22 A11 L2 L3 L4 L5 L6 L7 A12 A13 A14 A5 A6 A7 A A9 A A12 A13 A A15 杭体ひずみ 64ch A1 800 レーザー変位計 accelerometer 1 方向加速度計 laser displacement meter ひずみゲージ Unit:mm 単位 (mm) The locations of the measuring points 49

50 Depth(cm) model 1 model 2 model Acceleration(gal) The maximum acceleration response 50

51 The displacements of the existing pile and bridge pier Height(cm) model 1 model 2 model Displacement(mm)

52 Summaries of shaking table tests The dynamic response characteristics of the foundation reinforced with micropiles are proved free from problems. Micropiles are effective in reinforcing the existing foundation. Inclined micropiles can decrease the response of the existing foundation. 52

53 Design & Construction Manual for Seismic Retrofit Method for the Existing Bridge Foundation 53

54 Contents of Design & Construction Manual for Seismic Retrofit Method for the Existing Bridge Foundation Part 1 : General Part 2 : Design Chapter 1 : General Chapter 2 : Material Chapter 3 : Surveys Chapter 4 : General Instructions Chapter 5 : General Instructions for Seismic Retrofit Chapter 6 : Elastic Design for Ordinary time and Level Earthquake Chapter 7 : Ductility Design for Level Ⅱ Earthquake Chapter 8 : Detail Part 3 : Construction Chapter 1 : General Chapter 2 : Construction Procedures Chapter 3 : Quality Control & Quality Assurance 54

55 Lecture on the Design & Construction Manual 55

56 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 56

57 Length (m) Others Reinforcement of Slope New Foundation Seismic Retrofit for other Foundation Seismic Retrofit for the Existing Bridge Foundation Application of HMP 57

58 Construction Example 1 (Highway Bridge) P1 P2 P3 P4 P5 P6 P7 P8 Name of Bridge : RYUSENJI Viaduct Construction period : Oct., Mar., 2003 Number of micropiles : 95 piles (L= m) Total length of micropiles : 2418m 58

59 Construction Example 1 (Highway Bridge) Enlarged footing Bridge Pier PC pile(d600) HMP HMP(D178) 10 L=

60 Construction Example 1 (Highway Bridge) 60

61 Construction Example 1 (Highway Bridge) 61

62 Construction Example 2 (Electric Pylon) 62

63 Construction Example 2 (Electric Pylon) 63

64 Construction Example 2 (Electric Pylon) 鉄塔脚部 Tower leg Tie 既存 beam H 鋼繋ぎ梁 Existing pile 既存基礎 増設基礎 Enlarged footing Reinforcement beam 補強ビーム 高耐力マイクロパイル High Capacity Micropile 64

65 Construction Example 2 (Electric Pylon) 65

66 Construction Example 3 (Water service plant) 66

67 Construction Example 3 (Water service plant) 104m 7.7m WATER 104m Name of plant : Kameido Water service plant height : 7.7m Width : 104m x 104m Volume : 60,000m 3 67

68 Construction Example 3 (Water service plant) L=35-48m D600mm Existing piles The number of existing piles are

69 Construction Example 3 (Water service plant) 38-48m HMP D178mm 69

70 Construction Example 3 (Water service plant) Height 6.3m 70

71 Construction Example 3 (Water service plant) Grouting Head Cap 71

72 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 72

73 Caisson Type Pile Micropile Application of new Foundation 73

74 Effect when HMP is applied to new foundation Caisson Type Pile Micropile Structure 7m 16m 12m Amount of digging(m 3 ) materials piece % pieces %(+4%) Economy labor machine incidental facilities Total 43% 6% 12% 100% 21%(-22%) 22%(+16%) 4%(-8%) 90%(-10%) 74

75 Improvement of HMP Top Plate Footing Top Plate B ond Length Drilling casing Coupler for Steelpipe S oft G round Coupler for D eform ed B ar Steelpipe C entralizer Drilling B it D eform ed B ar Grout B ond Length New Type HMP Diameters are larger than standard HMP. Total length is a bond length. Standard Bearing G round New Type 75

76 Pull-out test of new type HMP 76

77 yield load;1800kn ultimate load;1980kn New-HMP Load(kN) Design load HMP Displacement( mm ) Pull-out test of new type HMP 77

78 NEW-HMP Application of NEW-HMP for Overpass 78

79 Topics 1. Introduction (Background of Research) 2. Joint Research A) Model test 1(horizontal loading tests of group piles) B) Static analysis for group piles (simulation analyses for the horizontal loading tests) C) Model test 2 (shaking table test of group piles) 3. Construction examples in Japan 4. Development in the future 5. Conclusion 79

80 Award of excellent new civil engineering technology ( ) 80

81 Thank you for your kind attention!! 81