available in the R. S. J. designing a steel plate girder bridges. 15.5). EXAMPLE 7 - GIRDER HAUNCH AND CAMBER 1 21 Design Example 7 Case 1: Bulb Tee Bridge Bridge Section View Girder Elevation View GIVENS Girder span length, L = 100 ft. Deck cross-slope, CS = 0.06 ft./ft. Copyright 10. 3.1 Construction Sequence . ii) The distance between centre of web of the beam = 200 cm. Specifically, the example illustrates the design of selected critical sections from an exterior girder at the Example: Design a slab and girder bridge with 7.5 m. clear roadway having a span of 12.0 m. between centre line of bearings. Eurocodes • EN 1991-1-1: Actions on Structures - General Actions • EN 1991-1-4: Actions on Structures - Wind Actions ����P��U���\j���x��Fb�ɚF���z�mu�)���́�ɋS�[�"�,�#�݉���9���A��{,�5ba����c������u��1���I %)�:t�1����>�W4T#Y�aջq ^k� :�V[?ո=�϶DN�Hr�HW��' Hence, the spacing of shear connectors is twice the previous value, i.e., 300 mm. �9��o�K���S%|��{�}�rs ś6�rG��7v2V���(AF���� �Y� 15.10 considering that max. Top and bottom bars provided for bending in case of slab and girder bridge (Fig. The load carrying capacity of steel girders can be increased to a great extent if some amount of tensile steel is added to the bottom flange and the girder is made monolithic with the deck slab. << /MediaBox [0 0 595 842] To prevent vertical separation between the top of girder and slab, anchorage device as shown in (Fig. Stresses in the Compound Steel Section due to self wt. 3 Design Preliminaries . From Fig. 15.3.2 = Effective flange width/m = 200/10 = 20.0 cm. This design example presents an alternative design for that presented in the Steel Bridge Design Handbook Design Example 2A. design is limited to the design of an interior girder. /Length 2114 of girder plus weight of slab, form work etc. The longitudinal shear at the interlace shall be resisted by the shear connectors and adequate transverse shear reinforcement. 15.9c, the total vertical shear due to dead load placed after composite action is effective and live load with impact near the support is 27,490 Kg. Equivalent Area of the Composite Section: The composite section consisting of R. C. deck slab and steel girder as shown in Fig. The primary goal of the Collaboration is to achieve steel bridge design and construction of the highest quality and value through standardization of the design, fabrication, and erection processes. dia 100 mm. << For 12 m span, impact factors for steel and concrete bridges are 25 per cent and 10 per cent respectively. Reinforced-concrete and steel were in competition during the 20 th century, and reinforced-concrete was still favored over steel … 1. ii) M. S. Stud shear connections which are proposed to be used in the bridge. >> may be used in this case. If two shear connectors are placed in one transverse line, shear resistance of 2 shear connectors = 2x 1350 = 2700 Kg. Design of Transverse Shear Reinforcement: The longitudinal shear force, VL per unit length transferred from the steel girder to the deck slab through any shear plane shall not exceed either of the following and transverse shear reinforcement shall be provided accordingly. ��=�T-�"�w�p�{�H�n��KK�¤��ƌ���eޘh��0[��0��X�N���y�d���3j�`!#q]�.�Fy]f­� �u��l"�-�.��n!�Q\��U�5Y?�`rW×L��1���+��so�78��Z/�E]V��"M��Y�l�H��$�H9��QPE)�Qq# Robert E. Schmidt, E.I.T. But the concrete around the shear connectors may fail by shearing by formation of shear planes as shown in (Fig. 15.9 shows the S.F. o;I��.O`U�LB_�� After 75 per cent maturity of the deck slab concrete, the item like footway slab, wheel-guard, railing and wearing course are cast. 3 . In addition, a design example for a two-span plate girder superstructure is included. Live load shear (single lane of Class 70R loading ) = 56,670 Kg. Assuming a steel stress for M. S. steel girder as 1500 Kg/cm2, Section modulus of the symmetrical R. S. J. When the deck slab after casting has gained strength at least up-to 75 per cent of the characteristic strength, the wheel-guard, footway slab, railing, wearing etc. The bridge deck will have no footpaths. 15.4a. Specifically, the design of a continuous steel wide-flange beam bridge is presented using a standard shape rolled I-beam, as an alternative to the plate girder design. Ec = Modulus of elasticity of concrete of deck slab. The detailing of the transverse shear reinforcement is shown in Fig. The girders are spaced at 2.5m (c/c girder). Design shear at 2.0 m. from support (Fig. The composite steel girder will have more area for bottom flange than that of the top flange and as such the steel section will be unsymmetrical about horizontal axis. FCk = Characteristics strength of concrete in Kg/ cm2. 15.3) shall be provided for all the shear connectors shown in (Fig. Area ... Neena S. Panandiker -"General Review of Composite Bridge", Design Advances In Bridge Engineering, March 24-25, 2006. 15.5 and taking moment from bottom, x X 212 = (40 x 2.0 x 1.0 + 132.0 x 29.5) = 3974. The distribution coefficient for outer girder as obtained for T-beam bridge is 1.45. For this purpose, the sectional properties of the composite section shall be determined. Design 2.1. There are two types of shear connectors viz. The composite girders are designed on the basis of any one of the following assumptions: i) The steel girders are adequately propped at least at mid-span and the quarter spans before the form-work is made and the deck slab is cast. = 66,590 Kg. >> APPENDIX B . LRFD Design Example for Steel Girder Superstructure Bridge SI Units Quicker in construction as no staging is required to be made for the casting of deck slab, if desired. Using 20 mm. 15.4a to 15.4d). ��Jf�3+y���P�em,�JF@�ˉ����+�����i���^m#&g�/�� ;Ѩ� {P���>�w��əJ �'���ٝq B��0�y!�'x�a o��Z-߫"9B��b��ph��3B�(��h SNcl~��y��p��E��+�� Total 1st Stage D. L. = 4080 + 985 = 5065 Kg/m. Because the example in Art. By using excel spreadsheet, the author compares the weight of the plate girder bridge designed using both codes as the span increases with a fixed yield strength used. : ... 6tg = {(25,060 x 100)/2755} = (+) 909.62 Kg.cm2 ; 6bg = {(25,060 x 100)/5620} = (-) 445.91 Kg/cm2. This again is dependent on the effective flange width of the composite section. may be cast after removal of props. << ��L���S7>M���cj�L����dӸ��W؟^���k�W����Q�0$��魲.�h�TH�oȾT����[_�ac��8G�A�o�u$NV/���{|�ܻ���C�S;g �>ۚ�nS���Xߺ�M Structural Steels Steel bridges are fabricated and constructed with steel elements that are produced at two different types of steel … 15.2). /TT6 9 0 R 5 0 obj provide general design guidance and information on detailing practices. Average L. L. moment per girder = 1, 87,000/4 = 46,750 Kgm. (Area = 132 cm2 and weight per metre = 104 Kg) (Fig. Centroidal Axis of the Equivalent Composite Section: Taking moment about the bottom of girder, x1 X 612 = Area of compound steel section x its CG distance from bottom + Area of concrete section (transformed steel area) x its C. G. distance from bottom. In such bridge decks, the bending moment caused by the loads from the bridge deck is resisted by the steel girders themselves without having any assistance from the deck slab for the fact that separation and slip due to longitudinal shear occur at the junction of deck slab and steel girders. Hence safe. 15.4. fck = Characteristics strength of concrete in MPa but not than 45 MPa. Ac = Transformed compressive area of concrete above the interface. Steel Beam and Girder Like the reinforced-concrete beam and girder bridge, the steel beam and girder bridge is closely linked to the evolution of the automobile. Three separate runs were performed. 1 Structural arrangement 5 2 Design basis 6 3 Actions on the bridge 11 4 Girder make-up and slab reinforcement 16 5 Beam cross sections 17 6 Global analysis 22 7 Design values of the effects of combined actions 27 Step 6. EN 1994 Part 2 Composite bridges Eurocodes. ISMB 550 x 190 has a section modulus of 2360 cm3. Girder analysis and design is performed using the computer program CONSPAN, Version 09.00.03.01. Shear due to 2nd Stage of dead load = ½ x 2795 x 12.0 = 16,770 Kg. These shear connectors offer the resistance by bending. The instant bridge is a combination of steel and concrete and as such an average impact factor may be considered in the design of shear connectors. 5 shows the bridge layout and cross section. 8.5) are 12 Φ @ 220 mm. These shear connectors prevent the slip by bearing against the concrete of the deck slab. Before publishing your articles on this site, please read the following pages: 1. (approx.) These runs included: DC1 loads applied to the noncomposite steel sec- tion and DC2 and DW loads applied to the long-term composite (3n = … /Filter /FlateDecode C. deck slab of M 20 concrete and 4 Nos. Design and detailing of the following items shall be done: i) Flexural resistance of the composite section and steel section of the composite girder. 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