土木工程英语Unit 4 Lecture 4.pptx

Unit4

BridgeandTunnelConstructionPartIVCriticalThinking

AboutthecolorofbridgesUsually,bridges,asoneofthemostcommonlyseencivilconstructionseverywhere,aredesignedtobelikeotherinfrastructures–tobemoreusefulthanfancy.So,thechoiceofcolorismoreoftenthannotbeingblackorgrey.

AboutthecolorofbridgesButGoldenGateBridge,beingonethebestknownbridgesintheworld,isfamousforitsburntred-orangehuecalledInternationalOrange.AndthiswascontributedbyIrvingMorrow,andarchitectwidelyknownafterthisdistinctivedesign.

CriticalthinkingtimeDiscusswithyourgroupmembers,andtrytofindoutwhyarchitectsselectedthiscolor.Hereisonepossibleanswer:SanFrancisco,unlikesunnyLosAngeles,isoftenfoggy.AndthedrivingconditiononthebridgeisworsebecauseofthewatervaporfromtheBay.Sotheredcolorissuitablefordrivinginfog.

SafetyconcernofbridgebuildingWhenthebridgeisunderconstruction,workersareexposedtogreatsafetyrisksasaresultofthenatureofbridge--linkinguncrossableterrainsInthetext,theauthormentionsasafetynethangingbelowthedeck,whichprotectsaccidentsfromhappening.

Criticalthinkingtime1.let’sthinkaboutthepotentialhazardsduringbridgeconstructionFirstandforemost,bridgeistoconnectthetwosidesofriverbanksormountains,soitishungoverwaterordeepvalley.Thusthegreatestdangercomesfromtheheight.

CriticalthinkingtimeSecondbiggesthazardisaboutlifting.Overloadofcranecables,orlackofmaintenanceofcraneparts,ortheerrorofstandingofworkers,areallthepossiblereasonsthatheavyliftedmaterialsfallandhitpeople.Let’snotforgetfire.Itisoneofthemostcommonaccidentsinallkindsofconstructionsites.Evenexplosionmayhappenwhenfirereachesexplosivegases.

Criticalthinkingtime2.Howtoimproveequipmentortosupervisesafetyprocedures?Tosetprotectingnetbeneathbridge,like