Steel structures Prepared by: Ehab Waleed Ibrahim Mohammad Khwailed Submitted to :

1. Steel structures Prepared by: EhabWaleed Ibrahim Mohammad Khwailed Submitted to : Dr. NabeelDmaidi

2. Types of steel Structures Steel structures can be used in a different ways according to the aims of constructions which could be: • Multistory buildings • Towers • Roof trusses • Bridges • Industrial buildings • Stadiums • Churches • Auditoriums • Theaters….etc.

3. Why we use the steel structure? Steel structure is found to be better than the concrete because of the following considerable reasons: • Steel beams give the same bearing capacity and strength with less size • The load goes on the foundation due to the steel supports is less than the concrete ones • Easy to execute and erecting comparing with the concrete. • No need of formwork and curing period • Faster delivery schedule • Cost much but more profitable • Possibility of mobility( change position of steel structure )

4. Standard Shapes Of Steel Sections Steel structures should be constructed with members fabricated from standard shapes such as • W beams • C channels • Structural Tees (I &H sections) • Angles • Pipes • Rods • Plates

5. Fabrication • Members made from standard rolled shapes are usually more economical than the fabricated ones. If the standard shapes are not available in sufficient sizes to supply the require strength . It is necessary to fabricate the members from several parts such as adding plates to the beam flange to stiffener the beam webs. • Fabrication include many operation • Welding • Drilling • Punching • Cutting • And fabrication also requires an accurate drawings and plans for the pieces that need adjustments. • So this operation increase the cost estimate in the bid documents adding them to the total cost or price as will show next.

6. Units of Measurements of steel The steel units measurements vary according to specimens to be used in the constructional projects as following: • Members (m) • Plates(m2) • Rods • Steel of ribs of slabs could be estimated by mass (ton) or number of steel rods to be used with the definite specification. • Lump sum when it is difficult to find an mathematical function to determine the required mass of steel Whatever the measurement unit of steel is, most of suppliers measure and price the required amount of steel by mass (tons), so after they fabricate or supply the required specification they go back to measure the mass and estimate price per ton.

7. Estimating the Cost of Steel Structure In estimating the cost of steel for a job, a contractor will submit a set of plans and specifications for the structure to a commercial steel supplier, then the supplier will estimate the submitted specifications as the following:- • -cost of standard structural shapes delivered to the steel supplier ( capital) • Cost of preparing drawings for use by the shop in fabricating the steel. • Cost of fabricating the steel shapes into finished members

8. Cost of transporting the steel to the field. • Cost of erecting the steel • Cost of field painting the steel structure • Cost of over head (general,insurance,taxes). • Labor & equipments • Profit The base cost of steel is subject to change due to economic conditions, therefore, the cost of anyone or all of these items may be vary considerably with respect the time. Also the cost is changed due to the schedule of delivery Quick orders require more hands ,overhead, overtime…and it could be more risky specially when transporting at night . So such these things should be taken into consideration and increase the cost to achieve the right balance.

9. Erecting Structural Steel Erecting the steel in the work field vary according to the size or the type of constructional project. So -It needs heavy machinery equipments such as cranes for tall steel structure(high bridges, towers , multistory building) -In sometimes the labors are enough to do the required tasks such as domestic works (windows screens, stairs..etc)

10. Method of Erecting To get a stable erecting of steel structure. It depends on the true way of connection or assemble the members. So they are two different methods of assembling the members: • Welding method. • Bolting method. In each way should we estimate the price of materials and equipment use through the execution such as welding machine and rods( diameter of rods must take into consideration). The equipments required for bolting and material is it fabricated or not. All these staffs should be written in the bid documents Using the bolting method is better specially at the condition of possibility to change the position of steel structures.

12. Illustrative pictures

19. The End Thanks For Litening