Explanation: Steel design, or structural steel design, is a branch of structural engineering that deals with the design of steel structures. A steel structure is made up of structural members made of steel that have standard cross-sectional profiles, chemical compositions, and mechanical qualities.

iii) semi-continuous steel design

Explanation: Addition of small quantity of copper increases resistance to corrosion. Even Chrome and Nickel are added to impart corrosion resistance property to steel.

Explanation: Steel has high strength per unit mass, highly durable, and is reusable. But steel is poor in fire and corrosion resistance, it needs to be protected.

Explanation: High carbon steel contains high carbon content. Hence it has reduced ductility, toughness and weldability.

Explanation: Stainless steel are low carbon steels to which a minimum of 10.5% chromium (maximum 20%) and 0.5% nickel is added.

Explanation: High carbon steel is used in transmission lines and microwave towers where relatively light members are joint by bolting.

Explanation: Steel structures and their elements are normally designed by limit state method. When limit state method cannot be conveniently adopted, working stress method may be used.

Net section area = 400×10 – 16×10 = 3820mm2 = 38.2 cm2.

This partial safety factor accounts for possibility of unfavourable deviation of material strength from characteristic value, variation of member sizes, reduction in member strength due to fabrication and tolerances and uncertainty in calculation of strength of members.

Explanation: Hydrostatic load is considered on liquid retaining structures or hydraulic structures. Wave and current load is considered in marine and offshore structure. Earth pressure is considered in basements, retaining walls, column footings, etc. Dynamic load is due to earthquakes and wind.

Explanation: The factors which influence earthquake resistance design are : (i) geographical location of structure, (ii) site soil and foundation condition, (iii) importance of structure, (iv) dynamic characteristics of structure such as strength, stiffness, ductility and energy dissipation factor.

Explanation: According to IS code, it is assumed that maximum wind load and earthquake load will not occur simultaneously on a structure. The following combination of loads with appropriate partial safety factors may be considered : (i)Dead load + imposed load, (ii) Dead load + imposed load + earthquake load or wind load, (iii) Dead load + wind load or earthquake load, (iv) Dead load + erection load.

Explanation: When the lever arm is to be extended to accommodate more number of bolts, bracket connection is used. The bracket type connection are more rigid than any other type of connection. But the fabrication cost is very high, so they are not adopted in general practice.

Explanation: Proof stress for minimum bolt tension is 0.7fub, where fub= ultimate tensile stress of bolt. Proof stress is an approximation for yield point for materials which do not have a definite one because of their structure.

Explanation: The following are the assumptions of first-order elastic analysis of rigid jointed frame : (i) materials behave linearly, (ii) yielding effects can be ignored, (iii) member instability effects such as those caused by axial compression can be ignored, (iv) frame behaves linearly frame instability effects such as those caused by moments due to horizontal frame deflection, etc can be ignored.

Explanation: (i)Rivet connection is associated with high level of noise pollution, (ii)needs heating rivet to red hot, (iii)inspection of connection is skilled work, (iv) removing poorly installed rivet is costly, (v)labour cost is high.

Explanation: The advantages of HSFG bolts over bearing type bolts are : (i) joints are rigid, (ii) bolts are not subjected to shearing and bearing stresses as load transfer is mainly due to friction, (iii) high static strength due to high frictional resistance, (iv) high strength fatigue since nuts are prevented from loosening, (v)smaller number of bolts results into smaller number of gusset plates.

Explanation: Pin connections are used in following cases : (i) truss bridge girders, (ii) hinged arches, (iii)tie rod connection in water tanks, (iv)as diagonal bracing connections in beams and columns, (v)chain-link cables suspension bridges.