Bridges: The science and art of the world's most inspiring structures

329 Pages·2010·2.4 MB·English

by  David Blockley

BRIDGES
This page intentionally left blank
BRIDGES
The Science and Art of the
World’s Most Inspiring Structures
David Blockley
1
3
GreatClarendonStreet,Oxfordox26dp
OxfordUniversityPressisadepartmentoftheUniversityofOxford.
ItfurtherstheUniversity’sobjectiveofexcellenceinresearch,scholarship,
andeducationbypublishingworldwidein
Oxford NewYork
Auckland CapeTown DaresSalaam HongKong Karachi
KualaLumpur Madrid Melbourne MexicoCity Nairobi
NewDelhi Shanghai Taipei Toronto
Withofficesin
Argentina Austria Brazil Chile CzechRepublic France Greece
Guatemala Hungary Italy Japan Poland Portugal Singapore
SouthKorea Switzerland Thailand Turkey Ukraine Vietnam
OxfordisaregisteredtrademarkofOxfordUniversityPress
intheUKandincertainothercountries
PublishedintheUnitedStates
byOxfordUniversityPressInc.,NewYork
#DavidBlockley2010
Themoralrightsoftheauthorshavebeenasserted
DatabaserightOxfordUniversityPress(maker)
Firstpublished2010
Allrightsreserved.Nopartofthispublicationmaybereproduced,
storedinaretrievalsystem,ortransmitted,inanyformorbyanymeans,
withoutthepriorpermissioninwritingofOxfordUniversityPress,
orasexpresslypermittedbylaw,orundertermsagreedwiththeappropriate
reprographicsrightsorganization.Enquiriesconcerningreproduction
outsidethescopeoftheaboveshouldbesenttotheRightsDepartment,
OxfordUniversityPress,attheaddressabove
Youmustnotcirculatethisbookinanyotherbindingorcover
andyoumustimposethesameconditiononanyacquirer
BritishLibraryCataloguinginPublicationData
Dataavailable
LibraryofCongressCataloginginPublicationData
LibraryofCongressControlNumber:2009942577
TypesetbySPIPublisherServices,Pondicherry,India
PrintedinGreatBritain
onacid-freepaperby
ClaysLtd,StIvesPlc
ISBN 978–0–19–954359–5
1 3 5 7 9 10 8 6 4 2
Contents
ListofIllustrations vii
Acknowledgements xi
Introduction xv
1. Bridges Are BATS:
Whywebuildbridges 1
2. Underneath the Arches:
Bridgesneedgoodfoundations 36
3. Bending It:
Bridgesneedstrongstructure 74
4. All Trussed Up:
Interdependencecreatesemergence 111
5. Let It All Hang Down:
Structuringusingtension 149
6. How Safe is Safe Enough?:
Incompletescience 206
7. Bridges Built by People for People:
Processesforjoined-upthinking 242
Endnotes 281
Glossary 293
Bibliography 297
Index 301
This page intentionally left blank
List of Illustrations
1. LondonMillenniumBridge 3
2. Shearforce 20
3. Ibeamsandothercomponents 20
4. ForthRailwayBridge 26
5. Michelangelosketchofbridgescaffoldforpainting
oftheSistineChapel 31
6. Author’ssketchofthetrussbridgeusedinthe
restorationoftheSistineChapelfrom1981to1994 33
7. MasonryArchBridgeatBradfordonAvon
nearBath,UK 37
8. CentringfortheSalginatobelBridge,
Switzerland 38
9. Behaviourofacorbelwall 45
10. Theforcesinamasonryarch 50
11. IronbridgeatCoalbrookdale,UK 56
12. Brunel’sSaltashBridge 58
13. TheSalginatobelBridge,Switzerland 67
14. TheClydeArcFinniestonBridge,Glasgow 68
15. ClapperBridge,TarrStepsExmoor,UK 76
16. TheundersideoftheSecondSevern
Crossingapproachspans 81
17. Thedeflectedshapesofbeams 84
18. Internalforcesinabeam 87
vii
LIST OF ILLUSTRATIONS
19. Bendingmomentandshearforcediagramsfor
asimplysupportedbeam 92
20. Bendingmomentandshearforcediagrams
foratwo-spancontinuousbeam 94
21. Internalforcesinamodernarch 102
22. Someformsoftruss 117
23. Internalforcesatthreecutsinakingposttruss 121
24. Internaltensionforceinrafteroftruss 122
25. Triangleofforces 124
26. InternalforcesinaPratttruss 130
27. ErectionofalegoftheForthRailwayBridge 134
28. CaissonofForthRailwayBridge 136
29. Typesofweld:(a)filletweldand
(b)buttweld 141
30. FlisaBridge,Norway 147
31. SnowyCreekBridge,NewZealand 151
32. Typesofhangingbridges 154
33. MillauViaduct,France 155
34. PontdeNormandie 156
35. Deflectionsoftensioncable 159
36. Internalforcesinsuspendedcable 161
37. BrooklynBridge,NewYork 167
38. CrosssectionsofBrooklynBridge 171
39. Internalforcesinasuspensionbridge 173
40. Internalforcesinacable-stayedbridge 194
41. TheGoodwillBridge,Brisbane,Australia 201
42. MihoBridge,Japan 202
43. PuentedelAlamillo,Seville,Spain 204
44. Internalstressesinabeam 213
45. Coordinateaxes 220
viii
LIST OF ILLUSTRATIONS
46. Distributionofloadversusstrength 222
47. Plastichinges 227
48. Turningonatap 258
49. Integratingprocessesforbridgebuilding 261
50. Feedbackforlearning 275
ix