PART IV SUBSTRUCTURES
CHAPTER 1

GENERAL ······················································································· 1

1.1 Scope ········································································································· 1
1.2 Definitions ·································································································· 2
1.3 Fundamentals of Design Calculations······························································ 3
1.4 Conditions of Construction for Design······························································ 4
1.5 Items to be Shown in Drawings ······································································ 5

CHAPTER 2SURVEY··························································································· 7

2.1 General ······································································································ 7
2.1.1 Fundamentals ······················································································· 7
2.1.2 Types of Surveys ··················································································· 7
2.2 Geotechnical Investigation··········································································· 15
2.2.1 General ······························································································ 15
2.2.2 Preliminary Surveys············································································· 17
2.2.3 Principal Surveys ················································································· 19
2.2.4 Evaluation of Geotechnical Parameters for Design ···································· 30
2.3 Survey of River Characteristics and Water Utilization ····································· 36
2.4 Survey of Construction Conditions ································································ 37

CHAPTER 3

FUNDAMENTALS OF DESIGN ························································ 39

3.1 General ···································································································· 39
3.2 Load Combinations in Design Calculations····················································· 41
3.3 Verification of Safety for Loads ····································································· 47

CHAPTER 4

ALLOWABLE STRESSES ································································· 50

4.1 General ···································································································· 50
4.2 Allowable Stresses of Concrete ····································································· 52
4.3 Allowable Stresses of Reinforcing Bars ·························································· 61
4.4 Allowable Stresses of Steel Materials for Structures ········································ 64
4.5 Allowable Stresses of Prestressing Steel Materials ·········································· 65iCHAPTER 5

VERIFICATION OF STRUCTURAL MEMBERS ·································· 67

5.1 Verification of Structural Members for under Ordinary, Strom, and Level 1
Earthquake Conditions. ·············································································· 67
5.1.1 General ······························································································ 67
5.1.2 Verification of RC Members Subjected to Bending Moments or Axial Forces ·· 67
5.1.3 Verification of RC Members Subjected to Shear Forces ······························· 68
5.2 Verification of Members for Under Level 2 Earthquake Condition ······················ 72
5.2.1 General ······························································································ 72
5.2.2 Verification of RC Members Subjected to Bending Moments or Axial Forces ·· 73
5.2.3 Verification of RC Members Subjected to Shear Forces ······························· 74

CHAPTER 6

DURABILITY ·················································································· 77

6.1 General ···································································································· 77
6.2 Examination of Salt Damage········································································ 78

CHAPTER 7

STRUCTURAL DETAILS OF REINFORCED CONCRETE MEMBERS ··· 83

7.1 Scope ······································································································· 83
7.2 General ···································································································· 83
7.3 Minimum and Maximum Amount of Reinforcement ········································· 84
7.4 Concrete Cover for Reinforcing Steel ····························································· 87
7.5 Spacing of Reinforcing Steels ······································································· 88
7.6 Anchorage of Reinforcing Steel ····································································· 89
7.7 Hook and Bent Shape of Reinforcing Steel······················································ 94
7.8 Joint of Reinforcing Steels ··········································································· 97
7.9 Axial Reinforcement Bar ············································································ 100
7.10 Shear Reinforcements ·············································································· 100

CHAPTER 8

DESIGN OF PIERS, ABUTMENTS, FOOTINGS, AND ABUTMENT BACKAPPROACH··················································································· 107

8.1 Scope ······································································································ 107
8.2 General ··································································································· 107
8.2.1 Location, Type, and Configuration of Piers and Abutments ······················· 107
8.2.2 Design of Structures with Large Width ··················································· 110ii

8.2.3 Protection Against Colliding Objects ······················································ 111
8.3 Design of Piers·························································································· 111
8.3.1 T-shaped Piers ···················································································· 111
8.3.2 Rigid-frame Piers ················································································ 116
8.4 Design of Abutments ·················································································· 119
8.4.1 Reverse T-shaped Abutments ································································ 119
8.4.2 Skew Abutments ················································································· 124
8.4.3 Design of Parapets ·············································································· 128
8.4.4 Design of Wing Walls ··········································································· 134
8.5 Substructure body -Footing Connections ······················································· 137
8.6 Design of Bridge Seats ··············································································· 138
8.7 Footings··································································································· 145
8.7.1 General ····························································································· 145
8.7.2 Thickness of Footings ·········································································· 146
8.7.3 Design for Bending Moments ································································ 149
8.7.4 Design for Shear Forces ······································································· 154
8.7.5 Arrangement of Reinforcement······························································ 166
8.8 Abutment Jointless Structure ····································································· 170
8.9 Abutment Back Approach ··········································································· 175

CHAPTER 9

FUNDAMENTAL REQUIREMENTS FOR STABILIZATION OF
FOUNDATIONS ············································································ 182

9.1 General ··································································································· 182
9.2 Basic Requirements of Design ····································································· 186
9.3 Selection of Foundation Types ····································································· 194
9.4 Selection of Bearing Layer and Embedment Depth Requirements ····················· 196
9.5 Design Ground Surface ·············································································· 202
9.6 Coefficients of Subgrade Reaction ································································ 205
9.6.1 General ····························································································· 205
9.6.2 Coefficients of Subgrade Reactions························································· 206
9.7 Calculation of Subgrade Reaction and Displacement ······································· 210
9.7.1 General ····························································································· 210

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9.7.2 Subgrade Reaction Elastic Displacement ················································ 211
9.8 Deep Foundations to be Constructed Deep in Grounds Subject to Consolidation
Settlement ······························································································· 211
9.9 Foundations Subjected to Eccentric Loads ····················································· 212
9.10 Foundations of Skewed Abutments ····························································· 215

CHAPTER 10 DESIGN OF SPREAD FOUNDATIONS ············································ 218
10.1 Fundamentals of Design ··········································································· 218
10.2 Load Shearing························································································· 221
10.3 Allowable Bearing Capacity of Ground ························································ 222
10.3.1 Allowable Vertical Bearing Capacity of Ground below Base of Foundation ·· 222
10.3.2 Allowable Horizontal Bearing Capacity of Ground ·································· 232
10.3.3 Allowable Shear Resistance of the Ground below the Base of a Foundation ··· 232
10.4 Coefficients of Subgrade Reactions ····························································· 236
10.5 Calculation of Subgrade Reaction Intensity and Displacement ························ 239
10.6 Design of Footings ··················································································· 242
10.7 Treatment of Foundation Base and Backfill Materials ··································· 245
10.7.1 Foundation Base ··············································································· 245
10.7.2 Backfill Material ··············································································· 246

CHAPTER 11 DESIGN OF A CAISSON FOUNDATION ·········································· 247
11.1 Basic Requirements of Design ···································································· 247
11.2 Load Sharing ·························································································· 250
11.3 Shapes and Dimensions ············································································ 252
11.4 Allowable Bearing Capacity of Soil Layer ···················································· 255
11.4.1 Allowable Vertical Bearing Capacity of Soil Layer ··································· 255
11.4.2 Allowable Shear Resistance of Soil Layers at the Bottom of Foundation ····· 262
11.4.3 Negative Skin Friction ······································································· 262
11.5 Coefficient of Ground Reaction and Upper Limit Value of Subgrade Reaction ···· 264
11.5.1 Coefficient of Ground Reaction ···························································· 264
11.5.2 Upper Limit Value of Ground Reaction ················································· 268
11.6 Calculations of Sectional Force, Ground Reaction, and Displacement ··············· 272
11.7 Design of Various Members of Foundation ··················································· 280

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11.7.1 Caisson Side Wall and Partition ··························································· 280
11.7.2 Top Slab ··························································································· 289
11.7.3 Top Slab Bearing Unit ········································································ 292
11.7.4 Bottom Plate of Open Caisson ····························································· 294
11.7.5 Cutting Edge ···················································································· 295
11.7.6 Ceiling Slab for Pneumatic Caisson Working Chamber and Suspended Beams for
the Ceiling Slab ················································································· 297
11.7.7 Parapet ···························································································· 299
11.7.8 Examination of Stresses during Construction ········································ 300
11.8 Verification for Level 2 Earthquake Condition ·············································· 301
11.8.1 Basics of Verification ·········································································· 301
11.8.2 Yield of Foundation ············································································ 303
11.8.3 Allowable Ductility Factor and Allowable Displacement of Foundations ····· 305
11.8.4 Calculation of Sectional Force, Subgrade Reaction and Displacement ········ 306
11.8.5 Verification of Members ······································································ 311
11.9 Details of Structure ·················································································· 314
11.9.1 Construction Joint ············································································· 314
11.9.2 Reinforcement around Pneumatic Caisson Shaft Holes ···························· 314
11.9.3 Arrangement of Reinforcing Bars on the Side Walls ································ 315

CHAPTER 12 DESIGN OF PILE FOUNDATIONS ·················································· 317
12.1 Fundamentals of Design ··········································································· 317
12.2 Load Shearing························································································· 320
12.3 Arrangement of Piles················································································ 320
12.4 Allowable Bearing Capacity of Piles ···························································· 323
12.4.1 Axial Allowable push-on bearing capacity of Single Pile ··························· 323
12.4.2 Axial allowable pull-out resistance force of Single Piles ··························· 338
12.4.3 Negative Skin Friction ······································································· 342
12.4.4 Consideration of Group Piles Effects····················································· 348
12.5 Coefficient of Horizontal Subgrade Reaction ················································ 351
12.6 Spring Constants of Piles ·········································································· 352
12.6.1 Axial Spring Constants of Piles···························································· 352
12.6.2 Radial Spring Constant of Piles ··························································· 354v

12.7 Calculation of Pile Reactions and Displacements ·········································· 358
12.8 Design of Pile Foundation under Special Conditions······································ 362
12.9 Design of Pile ·························································································· 370
12.9.1 Design of Piles against Loads after Construction ···································· 370
12.9.2 Pile Joints ························································································ 373
12.9.3 Connections between Pile and Footing ·················································· 374
12.9.4 Designs for Construction Period··························································· 380
12.10 Verification for Level 2 Earthquake Condition ············································ 381
12.10.1 Basics of Verification ········································································ 381
12.10.2 Yielding of Foundation ····································································· 383
12.10.3 Allowable Ductility Factor and Allowable Displacement of Foundation ····· 384
12.10.4 Calculation of Sectional Force, Pile Head Reaction and Displacement ······ 385
12.10.5 Verification of Members ···································································· 393
12.11 Structural Details ·················································································· 396
12.11.1 PHC Piles ······················································································· 396
12.11.2 Cast-in-place RC Piles ······································································ 399
12.11.3 Steel Pipe Piles················································································ 404
12.11.4 Steel Pipe Soil Cement Piles ······························································ 410
12.11.5 SC Piles ························································································· 411

CHAPTER 13 DESIGN OF STEEL PIPE SHEET PILE FOUNDATION······················ 414
13.1 Basic Requirements of Design ··································································· 414
13.2 Load Sharing ·························································································· 417
13.3 Shape and Size ························································································ 418
13.4 Allowable Bearing Capacity of a Steel Pipe Sheet Pile ··································· 420
13.4.1 Allowable Bearing Capacity of a Steel Pipe Sheet Pile ····························· 420
13.4.2 Allowable Pull-out Force of a Steel Pipe Sheet Pile ································· 422
13.4.3 Negative Skin Friction Effect of Consolidation Settlement ······················· 423
13.5 Coefficient of Ground Reaction··································································· 426
13.6 Calculation of Sectional Force, Unit Ground Reaction and Displacement ·········· 427
13.7 Design of Various Members of Foundation ··················································· 434
13.7.1 Steel Pipe Sheet Pile ·········································································· 434

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13.7.2 Top Slab ··························································································· 434
13.7.3 Design of Connection between Top Slab and Steel Pipe Sheet Pile ············· 436
13.8 Cofferdam ······························································································ 437
13.9 Verification for Level 2 Earthquake Conditions ············································ 438
13.9.1 Basics of Verification·········································································· 438
13.9.2 Yield of Foundation············································································ 438
13.9.3 Allowable Ductility Factor and Allowable Displacement of Foundation ······ 440
13.9.4 Calculation on Sectional Force, Ground Reaction and Displacement ········· 440
13.9.5 Verification for Strength of Members ···················································· 444
13.10 Details of Structure ················································································ 445

CHAPTER 14 CAST-IN-SITU DIAPHRAGM WALL FOUNDATION DESIGNS ··········· 449
14.1 Basic Requirements of Design ··································································· 449
14.2 Load Sharing ·························································································· 452
14.3 Shape, Size, and Joint ·············································································· 453
14.4 Allowable Bearing Capacity of Ground ························································ 454
14.4.1 Allowable Vertical Bearing Capacity of Foundation Bed Ground ··············· 454
14.4.2 Allowable Shear Resistance of Foundation Bed Ground ··························· 455
14.4.3 Negative Skin Friction ······································································· 456
14.5 Coefficient of Ground Reaction and Upper Limit Value Of Subgrade Reaction ··· 458
14.5.1 Coefficient of Ground Reaction ···························································· 458
14.5.2 Upper Limit Value of Ground Reaction ················································· 460
14.6 Calculations of Sectional Force, Ground Reaction, and Displacement ··············· 462
14.7 Design of Foundation Body ······································································· 463
14.8 Verification for Level 2 Earthquakes ··························································· 465
14.8.1 Principles of Verification ····································································· 465
14.8.2 Yield of Foundation············································································ 466
14.8.3 Allowable Ductility Factor and Allowable Displacement of Foundation ······ 466
14.8.4 Calculation on Section Force, Subgrade Reaction and Displacement ·········· 466
14.8.5 Verification for Strength of Members ···················································· 468
14.9 Details of Structure ················································································· 469
14.9.1 Joint between Elements ····································································· 469

vii

14.9.2 Connection between Cast-in-situ Diaphragm Walls and Top Slabs ············· 470
14.9.3 Thickness of Wall ·············································································· 470
14.9.4 Arrangement of Reinforcing Bars ························································· 471
14.9.5 Lap splice of Vertical Reinforcing Bars ·················································· 472

CHAPTER 15

Design of Deep Foundations ···························································· 474

15.1 Basic Requirements of Design ··································································· 474
15.2 Load Distribution ···················································································· 477
15.3 Geometries and Arrangement of Deep Foundations ······································· 481
15.4 Allowable Bearing Capacity of Ground ························································ 483
15.4.1 Allowable Vertical Unit Bearing Capacity of Foundation Bottom Ground ··· 483
15.4.2 Allowable Shear Resistance Force of Foundation Bottom Ground ·············· 486
15.5 Coefficients of Subgrade Reaction and Upper Limits of Unit Subgrade Reaction ·· 487
15.5.1 Coefficients of Subgrade Reaction ························································ 487
15.5.2 Upper Limit of Horizontal Unit Subgrade Reaction on Foundation Front ··· 491
15.5.3 Upper Limits of Unit Subgrade Reaction on Foundation Side and Foundation
Peripheral Surface ················································································ 493
15.6 Calculation of Sectional Force, Unit Subgrade Reaction, and Displacement ······ 495
15.7 Verification of Each Member of Foundations ················································ 497
15.7.1 Combined Deep Foundations ······························································· 497
15.7.2 Cylindrical Deep Foundations ····························································· 498
15.8 Verification of Performance under Level 2 Earthquake Conditions ·················· 500
15.8.1 Bases of Verification ·········································································· 500
15.8.2 Yield of Foundations ·········································································· 501
15.8.3 Calculation of Sectional Forces, Unit Subgrade Reaction, and Displacement ··· 501
15.8.4 Verification of Members ······································································ 503
15.9 Structural Details ···················································································· 503
15.10 Design of Earth Retaining Structure ························································· 505

CHAPTER 16

GEMERAL REQUIREMENTS ON EXECUTION OF WORK ·············· 508

16.1 Scope ····································································································· 508
16.2 General Items of Construction Work ··························································· 508
16.3 Survey for Construction Work ···································································· 509

viii

16.4 Execution Program ·················································································· 510
16.5 Work Record ··························································································· 512

CHAPTER 17

CONSTRUCTION OF CAISSON FOUNDATION ······························· 514

17.1 Method to be Applied ··············································································· 514
17.2 Selection of Construction Machines and Instruments ···································· 514
17.3 Cutting Edges ························································································· 515
17.4 Installation of a Caisson ··········································································· 515
17.5 Caisson Main Body ·················································································· 516
17.6 Excavation and Sinking ············································································ 517
17.7 Verification of Bearing Layer ····································································· 520
17.8 Top Slab ································································································· 522
17.9 Cut-off Walls and Temporary Retaining Walls ·············································· 522
17.10 Center ·································································································· 523
17.11 Concrete Filling of a Pneumatic Caisson ···················································· 524
17.12 Bottom Slab of an Open Caisson ······························································· 525

CHAPTER 18

CONSTRUCTION OF PREFABRICATED PILE FOUNDATION·········· 527

18.1 Method to be Applied ··············································································· 527
18.2 Selection of Construction Machines and Instruments ···································· 528
18.3 Test Piling ······························································································ 529
18.4 Preparation for Construction ····································································· 530
18.5 Transportation, Storage, and Inspection ······················································ 531
18.6 Installation····························································································· 531
18.7 Site-welded Joint ····················································································· 532
18.8 Finishing of a Pile Head ··········································································· 534
18.9 Driving a Pile and Finishing the Driving Operation ······································ 535
18.10 Pile-boring Method ················································································· 539
18.10.1 Excavation, Sinking and Retaining ····················································· 539
18.10.2 Treatment of a Pile Tip ····································································· 541
18.11 Preboring Pile Method ········································································ 543
18.11.1 Boring ···························································································· 543
18.11.2 Formation of Soil Cement Columns ···················································· 544

ix

18.11.3 Sinking and Retaining ······································································ 545
18.12 Steel Pipe and Soil Cement Composite Pile Method ····································· 545
18.12.1 Excavation ····················································································· 545
18.12.2 Preparation of Soil Cement Column ···················································· 546
18.12.3 Sinking and Retaining of Steel Pipe ···················································· 547
18.13 Screw Pile Method ················································································· 548

CHAPTER 19

CONSTRUCTION OF CAST-IN-PLACE PILE FOUNDATION ············ 551

19.1 Method to be Applied ··············································································· 551
19.2 Selection of Construction Machines and Instruments ···································· 552
19.3 Test Piling ······························································································ 552
19.4 Preparation for Installation······································································· 553
19.5 Excavation ····························································································· 554
19.6 Protection of Bore Wall from Collapse ························································· 555
19.7 Slime Treatment ····················································································· 557
19.8 Production and Installation of Reinforcement Cage ······································· 557
19.9 Concrete ································································································ 560

CHAPTER 20

CONSTRUCTION OF STEEL PIPE SHEET PILE FOUNDATION ······ 562

20.1 Method to be Applied ··············································································· 562
20.2 Test Piling ······························································································ 563
20.3 Installation of Guide Materials ·································································· 564
20.4 Driving a Pile and Finishing the Driving Operation ······································ 565
20.5 Filling Concrete and Finishing of Joint Pipes ··············································· 566
20.6 Cofferdam and Top Slab ············································································ 567
20.6.1 Construction of a Cofferdam································································ 567
20.6.2 Top Slab Connection and Top Slab ························································ 568
20.6.3 Removing Support Timbering and Steel Pipe Sheet Piles Acting as Cofferdam ·· 569

CHAPTER 21

CONSTRUCTION

OF

THE

CAST-IN-SITU

DIAPHRAGMWALL

FOUNDATION ············································································· 570
21.1 Method to be Applied ··············································································· 570
21.2 Test Work ······························································································· 570

x21.3 Preparations for Construction ··································································· 570
21.4 Excavation ····························································································· 571
21.4.1 Element Allocation ············································································ 571
21.4.2 Stability of Trench Walls ···································································· 572
21.4.3 Slurry ······························································································ 572
21.4.4 Excavation ······················································································· 573
21.4.5 Slime Processing ··············································································· 574
21.5 Fabrication & Installation of Reinforcement Steel Cages ······························· 574
21.6 Element Joints ························································································ 576
21.7 Concrete ································································································ 577

CHAPTER 22

CONSTRUCTION OF DEEP FOUNDATION ···································· 579

22.1 Method to be Applied ··············································································· 579
22.2 Selection of Construction Machines and Instruments ···································· 579
22.3 Preparation for Installation······································································· 580
22.4 Disposal of Spring Water and Ground Water ················································ 580
22.5 Excavation ····························································································· 581
22.6 Retaining Walls Structure ········································································· 582
22.7 Completion of a Bore Bottom ····································································· 583
22.8 Reinforcement Bars ················································································· 583
22.9 Concrete ································································································ 585
22.10 Backfilling ···························································································· 586

xi