Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
Gaurang Kakadiya, profile picture
Uploaded byGaurang Kakadiya
PPTX, PDF30,795 views

Erection of steel Structure

The document discusses the erection methods for steel girder and truss bridges, detailing various techniques such as lifting, staging, floating, rolling, and launching. It also covers essential considerations and data needed before construction, such as site conditions and equipment. Ultimately, the document serves as a guide for the erection processes utilized in bridge engineering.

Engineering◦
Downloaded 1,720 times
Shree Swami Atmanand Saraswati Institute of Technology Erection of Steel Girder and Steel Truss Bridges Prepared By :- Balar Piyush 110763106063 Vekariya Sandeep R. 120763106001 Kakadiya Gaurang A. 120763106002 Balar Jigar H. 120763106003 Guided By :- Prof. A.P. Satasia Prof. P. V. Trivedi Prof. R. R.Tripathi Railway Bridge & Tunnel Engineering
† Contents  Introduction to Steel Girder Bridges  Erection of Steel Girder Bridges  Methods  Erection of Steel Truss Bridges  References
† Introduction to Steel Bridges  The steel girder bridge is a structure in which a floor system and roadway, concrete or timber, is supported by girders, usually rolled section beams which are plain or encased in concrete  These are normally used for railways and rarely for highways  Following data should be collected prior to the erection of these bridges:  Time estimate for the construction of a bridge  Condition of proper equipment and machinery  Condition of bridge site  Facility for transportation and storage of materials at bridge site  Necessary supporting system for superstructure  Availability of steel structures  Width and depth of flow in the river  Height of bridge from river bed
Methods for erection of steel bridges Erection by Lifting Method Erection by Staging Erection by Floating Erection by Rolling Erection by Launching of single girder span † ERECTION OF STEEL GIRDER BRIDGES
† Erection of Steel Bridges  Methods  Erection by Lifting Method  Steel girders upto span of 30 m can be easily erected if the height is 5 to 6 m  This method is suitable for rivers which are dry for the most part of the year  A platform is created by filling earth to sufficient height and levelled  Girders are assembled on the river bed and field riveted/bolted  They are lifted into position by means of stiff-leg derrick cranes or ordinary rope worked from anchored crab winches  The flooring and the bracings are then field connected to the girders placed in position
SOLNA BRIDGE, STOCHOLM, SWEDEN
† Erection of Steel Bridges  Methods  Erection by Staging:  Favourable conditions:  Depth of water in the river is shallow  Height of superstructure above the river should not be excessive  Span should be simply supported  Staging consists of trestle frames which may be of steel or timber  Iron staging is lighter than timber staging and, therefore, can be easily transported  Staging is suitably designed and after it is constructed, the erection of steel girders is commenced on the staging
† Erection of Steel Bridges  Methods  Erection by Floating:  Favourable conditions for this method are:  Depth of water in the river is more Floating barges/pontoons are used to carry the steel girders Bridge is assembled on the barges and is floated into position when complete. The barges are so positioned that span is over the final alignment, when the jacks are used to lower the span on the bearings. Finally the barges are sunk by flooding the tanks
Coleman Bridge, York River in Yorktown
† Erection of Steel Bridges  Methods  Erection by Rolling:  This method is adopted for erection of continuous girders on deep gorges  First span near the abutment is erected by any one method of erection  Girders of the first span are brought to the required position by rolling them from the abutment through the erected span  This method is also known as the Incremental Launching Method and has become very popular for the concrete girders  Second span is cantilevered when it projects from the erected span and acquires counter weight for its stability  This counter weight is provided by the successive span connected to it and its back
† Erection of Steel Bridges  Erection by Launching of single girder span  Each girder is first assembled on a track of rollers behind one of the abutments and is cantilevered as far as possible over the span.  The lifting blocks are then fastened to the outmost point of the girder and the heavy wire is coupled to the winch.  Rear end of the girder is tied to another winch which is released slowly so that sudden forward motion may no take place.
† Erection of Steel Truss Bridges  These bridges are erected with the help of a stiff derrick traveller and two false work bents  Erection procedure may be described in four stages:  Second stage  Move traveller (crane) to B  Erect false work bent T2  Assemble the section BC  First stage  Erect false work bent T1  Assemble the section AB
† Erection of Steel Truss Bridges  Third stage  Move traveller to C  Remove false work bent T1 from B and erect it at D  Assemble the section CD  Fourth stage  Move traveller (crane) to D  Assemble the section DE  Release the false work bent T1 and T2
† References  ftp://ftp.mdt.mt.gov/research/LIBRARY/NSBASBEGS-1-OL- STEEL_BRIDGE-AASHTO.PDF  http://www.deldot.gov/archaeology/historic_pres/hist_bridge_surv ey/pdf/steel.pdf  http://www.kwhconstructors.com/img/gallery/williamr.bennettbridg e/wrb_bridge5.JPG
Erection of steel Structure