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Normally the girts are quite slender, and also simply supported, so will typically provide limited lateral support. Also, the column next door will often be loaded to the state so may be buckling at the same time, so cannot be relied to provide stability. However, there are detailed design methods to evaluate whether members can be considered to provide lateral support.

@@firesun thank you for your explanation

Pleasure. Glad it was useful.

A number of structural fire engineering videos are provided in this playlist: czcams.com/play/PLcXEIpaMKkuq2PknC_UsIErB1igWxPYQ2.html

The girts provide lateral support about the weak axis so Ly is shorter.

UDL x span between nodes = 10kN/m x 1m = 10 kN (or half of this for the end bays)

L3 is a cantilever. On the right side it is free. On the left side it is continuous with lateral and torsional support. If assumed to be a destabilising load then we end up with K = 2.5.

You can have a look here and at the channel "Richard Walls" for various structural engineering videos.

Unfortunately that is not true. Often in practice bolts are placed within the depth of I-beams to make a base pinned. Also, if a foundation is not sufficiently large enough it will rotate resulting in the base become pinned.

The reason it does not work if the enclosure is wood is because your HRR increases massively due to the contribution of the wood. The internal behaviour, burning duration, flame lengths, etc. will all be different from a timber compartment.

Its a light board. Glass screen with light passing through it, that is picked up when you write with special pens.

The plastic kit comes from a toy shop. It is a kit for kids consisiing of balls with holes and plastic sticks. Just made it up and adding bracing from string.

Normally the length is taken as the distance from centre to centre of supports.

It depends. If you calculate that your beam needs 35.5 minutes of equivalent resistance based on the room geometry, and you provide 60 minutes then you are fine. 60 minutes would normally represent the code requirement, whereas an equivalent design time of 35.5 min represents an updated requirement. Hence, they are requirements based on different assumptions, rather than one being pass or fail.

Sorry, my brain does not work as well in lbs and inches. Strength is often governed by member capacity and also connections. Hence, if you strengthen something you also need to ensure that the connections between members are sufficient. As a rough rule of thumb if you take the area of concrete at around 40% of the strength, say 20 MPa for a low quality concrete, and add on strength of the rebar at 60% of its yield strength you have a ballpark estimate of the capacity. 800lbs is not that much load for a steel and concrete structure, especially if there are 4 legs.

It is possible to design a structure with moment resisting frames rather than bracing. However, it needs to be ensured the structure is braced in both directions. For minor axis bending that can be a problem unless a separate frame is added. However, without knowledge of the system discussed it is just speculative.

Unfortunately the bursaries for this year have closed. However, Indian students are equally welcome to apply for bursaries when they are open. We shall advertise more next year.

The application fee is not expensive, just a few hundred rand. We have advertised bursaries for full-time studies. We don't have bursaries for part-time students as they are typically sponsored by their companies or local countries.

When I worked in practice we did lots of glass furnaces at my old company. Few tests have been done on long-term strength reduction, where steel has been exposed to high temperatures for months, but spending time on Google scholar you might find something. The data available is probably suitable for long-term, but has not been verified in long-term tests. At a constant temperature I cannot see a chemical change occurring based on duration of testing. However, of greater concern is restrained thermal expansion if members cannot expand. That induces very high forces. Hence, my suggestion would be to ensure members are not restrained from expanding through careful connection detailing. However, may be sensible to used slightly reduced factors for the reduction factors based on uncertainty regarding long term effects.

1 / sin(45 degrees). It is to convert the diagonal force to a vertical force for sum of forces at a node.

You are unlikely to be able to turn a single plate of steel into a fire wall with insulation resistance using only intumescent. The steel normally fails insulation criteria before the intumescent has even activated. It is for structural resistance, and not compartmentation, that intumescents are applied

Stop the beam from deflecting (i.e. stiffen it) or isolate the members from each other.

@@firesun Regarding isolating the members from each other is there any code mentioned that, like IBC or AICS Standard, Please help me

@@ahmedyaqub2377 - You simply need to install a soft material that can accommodate the movement, and keep the wall and beams not connected to each other.

@@firesun Dea Sir, there is a controversy in our company that insulation is not required and it is possible to make the non-loading partitions directly contacted with steel truss without separation, so I need a paragraph in the code that stipulates that the isolation must be achieved

@@ahmedyaqub2377 You will not normally find this in a code. However, if a steel struss moves more than a wall can allow then the wall will crack. It is based on physics rather than codes.

Nope. Based on fundamental mechanics and structural analysis, rather than a code. However, most code guidelines follow such an analysis. Go find a structural engineer with grey hair and they will show you more useful techniques like this.

It prevents lateral torsional buckling (for Mr) and flexural buckling (for Cry).

SANS 10162-1, which is probably the most codes, defines a destabilising load as being on the top/tension flange.

Specifically in terms of cantilevers