Design of Steel and Timber Structure

(a) Design a suitable fillet weld for the bracket as shown in figure, if working load $P=200\text{ kN}$ and eccentricity $e=200\text{ mm}$. Thickness of the bracket plate is 12 mm and the column used is ISHB 300. [8] b) Design a double cover butt joint to transmit a working load of $300\text{ kN}$ to connect two flats 120 mm wide and 20 mm thick using M16 high strength bolts of property class 10.9. The cover plates are 12 mm thick. Assume that one shear plane intercepts the threads of the bolts.

(a) Discuss about allowable strength in working stress method of design and different factor of safety in limit state method of design. [4] (b) Explain the importance of local buckling and how it adversely affects the load carrying capacity of columns and beams? How is this accounted for in the design of steel members? [2+2] (c) Design a tension member of double angle section connected on the both sides of gusset plate 12 mm thick. The member is subjected to $a^n$ axial tension of $300\text{ kN}$. Use M16 bolts of property class 4.6 for connection.

(a) Design a lap connection to join two plates of 200 mm $\times$ 10 mm of grade E250 to mobilize full plate tensile strength using shop fillet welds. [4] (b) A diagonal member of a roof truss carries a maximum pull of 300 kN. Design the section and its connection with a 16 mm thick gusset plate. The length of the connection is limited to 340mm. Design the lug angles also if required. The steel of grade Fe 410 and bolts of grade 4.6 are to be used.

a) A office hall of clear dimension $18\text{ m}\times 6\text{ m}$ is provided with $12\text{ cm}$ thick RC slab over rolled steel beams $3\text{ m c/c}$. A wearing coat of $2\text{ cm}$ thick lime concrete is provided over RC concrete slab. The compression flange would be supported throughout its length by providing grooves in slabs. Design an intermediate beam with the following data. [14] Live load = $5.5{\text{ kN/m}}^2$ Unit wt. of cement concrete = $25{\text{ kN/m}}^3$ Unit wt. of lime concrete = $18{\text{ kN/m}}^3$ b) Find the design wind pressure on a sloping roof of span $10\text{ m}$ and pitch $1/4$. The height of the eaves is $5\text{ m}$ above ground. The building is situated in Delhi and its permeability is normal.

Discuss about procedure to estimate size of web plate and flange plate of a plate girder.

a) Design a built up column $10\text{ m}$ along to carry a factored axial compressive load of $1000\text{ kN}$. The column is restrained in position but not in direction at both ends. Design the column with connecting system as single lacing with bolted connection. Use two channel back to back. Assume steel of grade Fe 410, E250 C and bolts grade 4.6. [14] b) Explain about design process and Basis for design.

(a) A compression member is built using two channels ISLC 400 placed toe to toe. The effective length of the member is 8 m. The width over the backs of two channels is 400 mm. The channels are properly connected by lacings. Calculate the safe load for the member. Design the lacing systems using M16 bolts of property class 4.6. [12] (b) A column ISHB 350 carries $a^n$ axial compressive factored load of $1500\text{ kN}$. Design a suitable bolted gusset base. The base rests on M15 grade concrete pedestal. Use 24 mm diameter bolts of grade 4.6 for making the connections.

(a) The building is to be constructed in core city area for a 50 years life, the size of the building is over $30\text{ m}$. The height of the building is $36\text{ m}$ and is classified as 1st category building. Determine the wind pressure at the site and force on the truss. [10] (b) What do you mean by safety and serviceability requirements of steel structures? Explain it. [4] (c) Design a slab base for a column ISHB 350@ $710.2\text{ N/m}$ subjected to $a^n$ factored axial compressive load of $1000\text{ kN}$. Concrete pedestal of grade M20.

a) A building with large openings of size over $30\text{ m}$ and height $45\text{ m}$ is planned in a core city for a $50\text{ years}$ life. The building is planned to be located on a downward slope of $145\text{ m}$ high hill, the slope of which is $1\text{ vertical}$ and $3\text{ horizontal}$. The building has to be constructed at a height of $100\text{ m}$ above the base of hill. Determine the design wind pressure. [8] b) Design a timber beam of deodar wood having clear span $4\text{ m}$, support width $230\text{ mm}$ and subjected to uniformly distributed load of $20\text{ kN/m}$ including self-weight and point load $35\text{ kN}$ at mid span.

Design of braced built-up column using double channel-section, having unsupported length 3.0m, subjected to factored axial load of 1600 kN. Use single lacing as lattice member and bolted connection to connect lacing and column. The ends of the columns are effectively held in position at both ends but not restrained against rotation.

Design a slab base for ISSC 200 which has to carry a design axial load of $1200\text{ kN}$ resting on a concrete pedestal with M 20 grade of concrete.

A roof truss building ($20\text{m}\times 30\text{m}$) has height 5m up to eaves level and rise of a truss is 2m and is designed for the highly- dense city (Kathmandu). The minimum lifetime of the structure is 50 years. The site should be located 15m above the mean ground level and 100m far. If the crest level of the ridge is 200m from mean ground level, determine the maximum wind force on the roof truss.

Design a tension member of double angle section connected on the both sides of gusset plate 12 mm thick. The member is subjected to $a^n$ axial tension of $300\text{ kN}$. Use M16 bolts of property class 4.6 for connection.

Discuss about allowable strength in working stress method of design and different factor of safety in limit state method of design.