《MOVABLE AND LONG SPAN STEEL BRIDGES HOOL AND KINNE》

Section 1．Bascule Bridges1

DESIGNS AND TYPES OF BASCULE BRIDGES1

1．Early types1

2．Advant ages inherent in the bas-cule type1

a．Rapidity of operation1

b．Interference with channel during operation2

c．Duration of opening2

d．Pier considerations2

e．Adaptability to wide road-ways3

f．Safety to land traffic4

g．Effect of collisions with river craft5

h．Bascule vs.vertical lift5

3．Relative economy of the bascule type5

4．Cable lift bascules8

a．Spiral counterweight drums10

b．Sectional counterweights13

c．Curved track,and rolling counterweight13

5．Roller lift bascules15

6．Trunnion type bascules19

a．Simple trunnion or“Chic-ago”type20

b．Strauss type24

7．Semi-lift bascule spans25

8．Other types of bascule spans27

SELECTION OF TYPE OF BASCULE BRIDGES29

9．Single vs.double leaf29

10．Through vs.deck spans33

11．Arrangement of piers37

12．Relative merits of different types38

BASCULE SUPERSTRUCTURE DESIGN AND ERECTION PROBLEMS39

13．Balance requirements39

14．Live load stresses43

15．Dead load stresses46

16．Wind load stresses47

17．Floor design48

18．Erection features to be considered in the design49

19．Counterweights51

20．Design specifications peculiar to bascules57

FOUNDATIONS FOR BASCULE SPANS58

21．Conditions peculiar to bascule spans58

22．General description of a typical bascule pier63

23．Counterweight pits64

24．Anchor columns65

25．Tremie seal66

26．Operator's houses69

27．Pier fenders71

COMPLETE STRUCTURAL DESIGN OF A DOUBLE LEAF SIMPLE TRUNNION DECK BASCULE HIGHWAY BRIDGE71

28．Data73

a．General description73

b．Governing dimensions75

c．Loads75

d．Permissible stresses76

e．Counterweights78

f．Anchor arm lateral system78

g．Buffer blocks78

29．Design of floor system79

a．Flooring79

b．Stringers and floor beams79

c．Horizontal girder81

30．Design of main truss members81

a．Preliminary calculation of dead loads83

b．Determination of dead load stresses in counterweight arm86

c．Live load stress diagrams88

d．Shear lock stresses89

e．Dead load stresses—leaf open91

f．Wind load stresses92

g．Impact stresses92

31．Design of lateral system93

32．Miscellaneous parts of the moving leaf98

33．Fixed part99

a．Floor slab99

b．Stringers100

c．Columns on main girder100

d．Main trunnion girder101

e．Grillage braces103

34．Counterweight calculations and methods of balancing span104

DESIGN OF OPERATING MACHINERY124

35．General data for problem in hand124

36．Wind pressure assumptions125

37．Friction on trunnions125

38．Maximum starting force at the rack circle126

a．Inertia of the moving mass126

b．Wind resistance127

c．Frictional resistance127

d．Total tangential force at rack circle128

39．Design of rack and main drive pinion128

40．Machinery Iayout133

41．Design of gearing135

42．Design of shafting140

43．Keys for shaft S1143

44．Hand operating mechanism143

45．Centerlock mechanism144

46．Motor power required for center lock145

47．Design of center lock shafting149

48．Design of pin(P1)in crank149

49．Design of gearing for center lock drive150

50．Calculation for bearings for main pinion shaft152

51．Design for main trunnions152

52．Design of hand brakes154

Section 2．Vertical Lift Bridges158

1 Advantages of vertical lift bridges158

2．Classification of vertical lift bridges160

3．Adaptability of the different types of vertical lift bridges161

4．Description of a few vertical lift bridges163

5．General design notes172

Section 3．Swing Bridges180

CENTER-BEARING SWING BRIDGES180

1．General considerations180

2．Conditions of loading180

3．Stresses in a swing span182

4．Positive shear in panel 0-1.Case Ⅲ184

5．Positive moment about U3.Case Ⅲ186

6．Negative shear in panel 0-1.Case Ⅳ187

7．Shear in panel 1-2188

8．Shear in panel 2-3189

9．Shear in panel 3-4189

10．Shear in panel 4-5190

11．Shear in panel 5-6190

12．Moment about L2191

13．Moment about L4191

14．Moment about U5192

15．Moment about L6192

16．Case V,both arms loaded.Broken loads192

17．Negative shear in panel 5-6193

18．Moment about L6194

19．Dead load,bridge open.Case Ⅰ194

20．Dead load,ends raised.Case Ⅱ194

21．Combinations194

22．Reactions from Williot diagram194

RIM-BEARING SWING BRIDGES196

23．General considerations196

24．Partial continuity.Equal moments at center supports197

Section 4．Continuous Bridges199

DESIGN AND ERECTION OF CONTINUOUS BRIDGES199

1．Advantages of continuous bridges199

2．Economic comparisons with simple spans199

3．Economy of the continuous type200

4．Prejudices against the continuous type200

5．Conditions favorable for the continuous type201

6．Economic proportions and number of spans201

7．History of continuous bridges202

8．The Seiotoville Bridge202

9．Erection of the Sciotoville bridge208

10．The Allegheny River continuous bridge211

11．Ercetion of the Allegheny River bridge214

12．The Nelson River continuous bridge214

13．Ereetion of the Nelson River bridge217

14．The C.N.O.bridge at Cin-cinnati217

STRESSES IN CONTINUOUS BRIDGES218

15．The elastic curve218

16．Elastic curves for constant I218

17．Influence diagram for bending inoments220

18．Influence diagram for shears222

19．Two equal spans with symmetrical loading223

20．Two unequal spans223

21．Reactions for two continuous spans225

22．Moments and shears for two unequal spans225

23．Elastic curve for variable I226

24．Special case—Triangular variation of I227

25．Elastic curve for a continuous truss230

26．Example—Application of method to Sciotoville bridge232

27．Comparison of elastic curves for different assumptions234

28．Influence diagrams for contin uous trusses236

29．Determination of live load stresses236

30．Determination of dead load stresses237

31．Bridges continuous over three spans237

32．Elastic curves for three-span continuous bridge237

33．Symmetrical three-span contin-uous girders241

34．Influence diagrams for three-span continuous bridge244

35．The method of double influence lines246

36．Continuous bridge of three equal spans249

37．Multiple-span continuous girders249

38．Fixed points in continuous spans250

39．General rules for loading place-ment252

40．Effect of settlement of supports253

41．Example—Effect of settlement in Sciotoville bridge255

Section 5．Cantilever Bridges256

1．Cantilever bridges compared with continuous bridges256

2．The cantilever bridge as a de-velopment of the contin-uous bridge256

3．Statically determinate and stat-ically indeterminate canti-lever bridges257

4．Conditions of statical determi-nation257

5．Examples of cantilever bridges261

6．Computation for moments and shears262

7．Reactions for an indeterminate cantilever bridge269

8．Erection of cantilever bridges270

9．Special details270

a．Erection adjustments270

b．Anchorages275

c．Lateral systems279

d．Stringer expansion bearings280

10．Economy281

11．Relative rigidity283

12．Economical ratios of span lengths283

13．Miscellaneous data284

14．Arched cantilever bridges285

15．Some esthetic considerations288

Section 6．Suspension Bridges289

STRESSES IN SUSPENSION BRIDGES289

1．The cable289

a．Form of the cable for any loading289

b．The parabolic cable290

c．Unsymmetrical spans291

d．The catenary293

e．Deformations of the cable294

2．Unstiffened suspension bridges294

a．Stresses in the cables and towers295

b．Deformations under central loading295

c．Deformations under unsym-metrical loading296

d．Deflections due to elongation of cable296

3．Stiffened suspension bridges297

a．Assumptions used298

b．Fundamental relations299

c．Influence lines301

4．Three hinged stiffening trusses302

a．Analysis302

b．Moments in the stiffening truss303

c．Shears in the stiffening truss304

5．Two-hinged stiffening trusses306

a．Determination of the hori-zontal tension H306

b．Moments in the stiffening truss310

c．Shears in the stiffening truss311

d．Temperature stresses313

e．Deflections in the stiffening truss313

f．Straight backstays314

6．Hingeless stiffening trusses315

a．Fundamental relations315

b．Moments at the tower316

c．The horizontal tension H317

d．Moments in the stiffening truss318

e．Temperature stresses319

f．Straight backstays320

7．Braced-chain suspension bridges321

a．Three-hinged type321

b．Two-hinged type322

c．Hingeless type323

DESIGN OF SUSPENSION BRIDGES—CONSTRUCTION FEATURES324

8．Types of suspension bridges324

9．Economic proportions326

10．Chain construction327

11．Parallel wire cables328

12．Twisted wire ropes330

13．Towers332

14．Saddles332

15．Anchorages333

DESIGN CALCULATIONS FOR TWO-HINGED SUSPENSION BRIDGE WITH SUSPENDED SIDE SPANS333

16．Dimensions335

17．Stresses in cable335

18．Moments in stiffening truss—main span336

19．Bending moments in side spans338

20．Shears in stiffening truss—main span338

21．Shears in side spans340

22．Temperature stresses341

23．Wind stresses in bottom chords342

24．Design of tower343

25．Movement of top of tower343

26．Forces acting on tower344

27．Calculation of stresses in tower345

28．Wind stresses in tower345

29．Calculation of cablewire346

30．Calculation of cable diameter346

31．Calculation of wrapping wire347

32．Estimate of rope strand cables347

ERECTION OF SUSPENSION BRIDGES347

33．Erection of the towers347

34．Stringing the footbridge cables349

35．Erection of footbridges349

36．Initial erection adjustments350

37．Spinning of cables352

38．Erection of trusses and floor system353

39．Final erection adjustments54

40．Cable wrapping355

41．Erection of wire rope cables356

42．Erection of eyebar chain bridges357

43．Time required for erection357

Section 7．Steel Arch Bridges—General359

1．Classification and types of steel arch bridges359

2．Relative merits of various types of arch construction362

a．Fixed or hingeless type362

b．Single hinge type362

c．Two-hinged type362

d．Three-hinged type362

e．Various types in general363

3．Loadings on arch bridges363

4．Erection of arch bridges364

5．General design features368

a．Shape of arch368

b．Temperature stresses371

c．Location of crown hinge372

d．Tied arches373

Section 8．Analysis of Three-hinged Arch Bridges375

1．Equilibrium polygons375

2．Algebraic calculation of reac-tions378

3．Stresses due to moving loads(method of reaction lines)378

4．Influence lines for three-hinged arches381

5．Fiber stresses in solid ribbed arch spans385

6．Graphical analysis of stresses388

7．Wind stresses in spandrel-braced arch spans388

Section 9．Analysis of Fixed Arches393

FUNDAMENTAL THEOREMS RELATING TO INTERNAL WORK IN RIBS AND FRAMES393

1．The laws of internal work in structural frames393

2．Deflections and panel point dis-placements in frames396

3．Work expressions for solid web beams and cantilevers400

a．Derivation of expressions for internal work in ribs and beams404

4．Displacements and deflections in beams and ribs406

DEVELOPMENT OF THE GENERAL ELASTIC EQUATIONS FOR ARCH FRAMES OR TRUSSES5．Redundant forces in a fixed framed arch408

6．Residual frames409

7．Properties of the residual frame410

8．Development of the general elastic equations412

ELASTIC INFLUENCE LINES FOR FIXED FRAMED ARCHES414

9．Simplification of elastic equa-tions414

10．Application of above simplified formulas420

11．Horizontal and inclined loads426

12．Direction of the redundant forces426

THE ANALYSIS OF FIXED FRAMED ARCHES(SYMMETRICAL AND UNSYMMETRICAL SPANS)426

13．Unsymmetrical spans429

14．Symmetrical spans439

DEVELOPMENT OF GENERAL ELASTIC EQUATIONS FOR RIB ARCHES440

15．Development of formulas440

DEVELOPMENT OF ELASTIC INFLUENCE LINES FOR RIB ARCHES446

16．Development of formulas446

17．Graphical solution for redun-dant influence diagrams449

18．Stresses due to uniform temper-ature changes450

19．Stresses due to a variable tem-perature change452

20．Stresses due to rib shortening or axial thrust453

21．Symmetrical arch ribs454

COMPLETE ANALYSIS OF A 350-FT.FIXED STEEL ARCH RIB455

Section 10．Analysis of Two-hinged Arches483

INDEX489