Usman Altaf

Got your point. Yes. there is bracing provided in alternate/ end panels. Manufacturer of materials normally share the mechanical properties. I have those with me. I was curious if method of determining plate stresses will be applicable or not. The poles, i mean the columns have a proper concrete base, base plate and anchor bolts. They are not appearing in the picture. Thanks for your response. So to conclude your point, you are opting that i should not reduce the wind intensity and total force applicable on frame elements?

Hi All, I am designing a greenhouse that has steel as main supporting members and polythene sheet as cladding. Have a look at this image. My Client wants a minimal design. The governing loading is wind load. We all know that polythene sheet has significantly less strength as compared to steel and designing the steel frame assuming that the wind pressures are fully resisted by polythene cladding is not wise and would lead to a over design. I have following 2 questions: 1. Am I right that I should reduce the wind intensity/ wind forces on the steel members by a coefficient due to the presence of polythene sheet vs Steel, as it will burst/ puncture far earlier before resisting all the design wind pressures. 2. How to measure wind pressure sustaining capability of a polythene sheet. I knows its thickness (200 micron) and I know its tensile yield strength (20MPa). I know the spans across which its supported on the steel (300mm and 500mm). Is the method for calculating tensile stress similar to method used to determine tensile stress in steel sheet supported on all four sides (the coefficient method). or is there another method. Please guide. Thanks Usman

I agree with Umar. Normally the strength imparted by dowels exceed the requirement. So I would recommend simple checks only. Don't go for detail calculations. Dowels #6@ 9 inch center to center would work in all normal cases. Dowel bars are not expensive. The costly item is the grout that is injected in the drilled hole. Considering your structure, overall cost for dowels would not be significant. Thanks

@miqureshi77 Bearing capacity in Lahore varies from 0.5 Tsf to 1.25Tsf at around 3ft. below natural ground level, depending on location. Generally, shallow foundations work for a maximum of 3 floors. Thanks

Hi Rifat, You can refer Section 4-10 of Book 'Foundation Analysis and Design, Joseph E. Bowles' for a complete discussion on Bearing Capacity based on SPT values. Thanks

Hi All. I have been offered to take one technical training/ certification in Pakistan, supported by my organization. Unfortunately, I could not locate any good training institute/ international certification. Most trainings/ certifications are for Mechanical Engineers. I would be glad if anyone could share the technical traininng institutes/ international certifications available in Pakistan for Civil Engineers/ Structural Engineers/ Civil Design Engineers. Please exclude any software training for Etabs, Staad and SAP, Primavera as I have already taken these trainings. Thanks

Thanks @miqureshi77

Well explained by other members. It would be easier if you could share the front and side elevation of this building. Thanks

Introudce shear walls in your building system. You can introduce them around the stair case. The shear wall should span in direction you wish to reduce the displacement. Thanks

Well explained by Uzair. Generally, whenever you see more reinforcement on top, it indicates either the beam is doubly reinforced or it is continous. In your case, it appears the beam is singly reinforced as nominal steel is present on top.

Thanks @UmarMakhzumi @EngrUzair I got your point. @miqureshi77 The building is to be constructed in Sindh Secreteriat near MA Jinnah Road Karachi.

Hi all, I am designing the foundations of a small double storey building in Karachi for which no geotechnical investigation is envisaged. Can anyone tell me whats the average allowable bearing capacity in Karachi. Normally in Lahore, it ranges from 0.5tsf to 1.25 tsf. I would be glad if anyone can tell on basis of his experience in Karachi. Thanks