Analysis and Design of Cable Stayed Bridge Essays

Analysis and Design of Cable Stayed Bridge Essays Analysis and Design of Cable Stayed Bridge Essay Analysis and Design of Cable Stayed Bridge Essay Of the newly-built Bridgess, cable-stayed Bridgess are today really common worldwide for spans runing between 200 and 900 metres. A overseas telegram stayed span has one or more towers ( Pylons ) from which the overseas telegrams support the deck. This paper provides modeling, analysis and design of a prestressed harp type individual pylon overseas telegram stayed span utilizing MIDAS Civil. Keywords: overseas telegram stayed, box girder, prestressing, MIDAS Civil Introduction Of the newly-built Bridgess, cable-stayed Bridgess are today really common worldwide for spans runing between 200 and 900 metres. A overseas telegram stayed span has one or more towers ( Pylons ) from which the overseas telegrams support the deck. There are two major categories of cable-stayed Bridgess: harp and fan.In the harp design, the overseas telegrams are about parallel so that the tallness of their fond regard to the tower is similar to the distance from the tower to their climb on the deck.In the fan design, the overseas telegrams all connect to or base on balls over the top of the towers. The cable-stayed span is optimum for spans longer than cantilever Bridgess, and shorter than suspension Bridgess. This is the scope where cantilever Bridgess would quickly turn heavier if the span was lengthened, and suspension span telegraphing would non be more economical if the span was shortened Cable-stayed Bridgess may look to be similar to suspension Bridgess, but in fact they are rather different in rule and in their building. In suspension Bridgess, big chief overseas telegrams ( usually 2 ) bent between the towers ( usually 2 ) , and are anchored at each terminal to the land whereas in the cable-stayed span, the towers are the primary supporting constructions which transmitt the span loads to the land. A cantilever attack is frequently used to back up the span deck near the towers, but lengths farther from them are supported by overseas telegrams running straight to the towers. General presentation of the construction The span is a individual pylon overseas telegram stayed span holding a harp-type agreement of the overseas telegrams. The entire length of the overseas telegram stayed span is 700m with a chief span of 350m. The span construction carries 6 route lanes divided into 2 carriageways. The deck consists of dramatis personae in topographic point prestressed box girders Entire breadth of the span is 29.8m. Construction strategy The chief 350 m span will be built utilizing the cantilever method, get downing from the wharfs P4 A ; P5 at the same time. The two cantilevers will be connected at mid span by the mean of a stitch section. The balanced cantilevers are cast by sections of 3.5 m long, utilizing a signifier traveler. The section ( n ) is connected to old section ( n-1 ) by sinews ( internal pre-stressing ) . This method is used for the first 10 sections from pylon. After 11th section, no cantilever sinew is needed as the sections will be supported by stay overseas telegrams tensioned increasingly with building of sections. Hence building rhythm of sections after 11th one includes installing and tensioning of stay overseas telegram before remotion and launching of signifier traveller. Material features: Concrete: M50 grade concrete will be used for deck and pylons. M50 grade concrete will be used for Piers. Concrete belongingss shall be based on AASHTO LRFD Bridge Design Specifications. Young modulus as per IRC codification is given in the following tabular array ( IRC:21 Â § 303.1. ) : Shear modulus of concrete, G, is calculated utilizing the undermentioned equation: E= Ec/2 ( 1+? ) The coefficient of thermic enlargement and contraction for normal weight concrete is taken as 1.17?10-5 /Â °C. Density of the pre-stressed concrete is taken equal to 25 KN/m3. Steel support: Thermo-mechanically treated support bars of class 414 conforming to IS:1786 will be adopted. Yielding strength of inactive steel support is considered equal to 414 MPa and Young modulus equal to 200 000 Mpa. Modular ratio between concrete and steel will be taken equal to 10. Dead tonss: The self-weight is calculated presuming a denseness of 25 KN/m3 for reinforced and prestressed concrete. A denseness of 7.85 t/m3 is to be considered for steel. Live Tonss: Traffic live loads- The unrecorded tonss are in conformity with IRC:6-2000. The span has two carriageways of three lanes each and of 11 m breadth. Each carriageway will be loaded with three lanes of IRC category A burden. Pedestrian unrecorded burden ( PLL ) The pes way lading shall be as per clause 209 of IRC:6 with strength of lading equal to 500 kg/m? . Wind burden for overseas telegram stayed span: Harmonizing to IS:875 ( portion 3 ) -1987 Wind loads on unrecorded tonss ( WL ) The sidelong air current force against traveling unrecorded tonss shall be considered as moving at 1.5 m above the roadway and shall be assumed equal to 300 kg/m. Creep and Shrinkage ( C A ; S ) Creep and shrinking effects to be considered as per CEB-FIP codification for overseas telegram stayed span Earthquake tonss Rajasthan is located in seismal zone II. The horizontal seismal coefficient in longitudinal way will be calculated by IS 1893:2002 Construction tonss: Normal perpendicular loads- A building burden of 50 kg/m2 shall be considered during cantilever hard-on. Weight of the traveller signifier is assumed to be equal to 85 dozenss. An impact of 10 % shall be considered for the traveling building tonss. MIDAS MODEL of box: ( Half span ) AASHTO LRFD Bridge Design Specifications ( Third Edition, 2005 Interim Revisions ) ; AASHTO – Guide Specifications for Seismic Isolation Design ( 2nd edition – 2000 ) ; AASHTO – Guide Specifications for Design A ; Construction of Segmental Concrete Bridges ( 1999 ) ; IRC:6-2000 Standard Specifications A ; Code of Practice for Road Bridges, Section II, Loads A ; emphasiss ( 4th edition – 2000 ) ; for definition of the unrecorded tonss and temblor tonss merely ; IS:875 ( portion 3 ) -1987 Code of pattern for design tonss ( other than temblor ) for edifices and constructions ; for air current loads merely ; Necessities of Bridge technology by D.Johnson Victor Bridge Engineering Handbook Edited by Wai-Fah Chen, Lian Duan, CRC Press