Posts by Sompandh Wanant, P. In recent is 800 code 2007 steel pdf, it has become more desirable, and in many cases necessary, for architects and engineers to design buildings and structural frames with beams and girders of limited depth.
In high-rise building construction, it allows extra floors to be added within the proposed building height. On expansion projects, a shallower structural depth helps facilitate the need to match the existing floor elevations. This system has been developed for use in building floor construction, specifically for typical rectangular or square column bay areas of around 1,000 square feet. Conventional composite steel-concrete floor framing consists of rather deep steel beams and girders which provide the most cost-effective design in terms of tonnage of structural steel used.
45 feet can be designed economically. 2 or 3-inch deep steel deck may be used as required. Figure 2: Typical beam section. The thick and narrow flange plate provides not only needed strength and minimizes creep and long-term deflection, but also leaves adequate space required for field attachment of the steel deck to the steel girder built-up section. The steel girder built-up section and the steel-concrete composite slab form a very strong T-section flexural member.
One major advantage of this composite section is that field welding of the shear connectors to the steel girder top flange is not required since the top flange is embedded in the concrete slab with the top of the flange at or near the top of the concrete slab. Figure 3: Typical girder section. The imaginary homogeneous transformed section is analyzed for its physical properties by the elastic methods of analysis. As in any T-beam section, substantial flexural horizontal shear exists at the intersection of the web and the flange. For thin concrete slabs above the top of the steel deck, reinforcement is usually required to increase the shear capacity. 7 and its commentary are referred to for the design of concrete slab shear reinforcement. Please refer to ACI 318 for more design information.
Figure 4: Critical shear planes. With the existence of the steel deck, one may want to consider its strength, along with concrete, to help resist the horizontal shear. To ensure proper and uniform design of the composite girder section and to set the lower strength limit of the steel-only built-up section, the built-up section must have adequate strength to support the total slab dead load and its supporting steel frames. The effect of vibration on the comfort of the occupants and the function of the structure shall be considered. The system uses standard AISC beam-to-girder and girder-to-column connections, so the detailed connections are not shown.