Author: haroonkhan

Structural steel work is erected with the use of derricks, slings, guys, cranes, etc. The erection is done based on the drawings and keeping the verticality of the columns and fixing other members and parts of steel structure. During erection the steel work should be temporarily braced till the final stage is reached to allow…

Preparation of steel work for erection is called as fabrication. It includes all works necessary to layout, cut, drill, rivet or weld the steel sections. The fabrication has to be properly planned such that the work at the site of erection should be reduced as much as possible. Thus most of the work is carried…

Steel columns of simple type comprises of a single RSJ or a RSJ with two flange plates (Fig. 24.13). Compound columns may be made by riveting together two or three RSJs (Fig. 24.14). Other forms of compound columns commonly used are a combination of RSJs and channels or two angles, channels with flange plates or…

Steel beams include girders, lintels, etc. The simplest form of steel beam would be a single RSJ or an angle section for carrying small loads. In case of large loads, compounds ( built-up) sections are used. Compound beams comprise of two or more single RSJs connected together through bolts and separated suitably with separators which…

Various types of steel roof trusses are shown in Fig. 24.7(a–e) and 24.8(a–d). Steel roof trusses are designed in such a way that the members are either in compression or in tension only. Members of a truss which form the roof base depends upon the span, roof slope, covering materials, centre to centre of trusses,…

Different steel sections are used to form trusses, beams and columns. Individual steel sections or built-up sections are used.

In order to make steel structures, for example, beams and columns, the standard sections are combined in a suitable way. Such a combined section is called a built-up section. Figure 24.2 shows built-up sections composed of I-sections only. Likewise Fig. 24.3 shows built-up sections formed by combining I-section and plates. Figure 24.2 Built-up sections formed by…

There are two principal forms of welding of steel, viz., electric arc welding and oxyacetylene gas welding. The electrical welding is further divided into resistance arc, shielded arc and atomic hydrogen welding. In both the types of welding, the members to be welded are placed in contact and edges are melted so that the metal…

Bolt joints are used for temporary connections. For bold joints, the diameter of the hole is kept 1 mm larger than the external diameter of the bolt threads. In difficult situations, such as lesser number of rivets or difficulty in connecting, bolt connections are resorted to.

Members are connected by rivet which can not be removed unless the rivet is destroyed. Rivets are either fitted at site or in the fabrication shop. The former is called field rivets and the latter as shop rivets. Rivets used in building construction are of soft steel with a tensile strength of the order of…