You are probably right tempeng. I feel that the USA is regulating the practice of engineering (civil/structural) in a similar way that they regulate the practice of law or medicine. On the other hand, the UK/Europe sees the practice of engineering in a different light than the practice of law or...
Hi Shang, min thickness of Foundation depends on code.
However in practice, I would assume a concrete cover of 75 for bottom bar and 50 for top bar, that adds into about 125 but since you must have a lever arm for the rebars to "work" you must say add another 100mm to cater for the bar diameter...
Sorry if I wrote a blanket statement regarding the USA's licensing system, it is correct that its regulated depending on each states regulation.
I do agree with the statements put up by Teguci & Tempeng. Regulation in the USA is more straightforward compared in the UK (or should I say Europe...
Hi All, I lived and studied in a country which follows the USA in terms of regulating the practice of engineering (Civil), that is PE license is given by a government authority which requires you to gain an x amount of experience then sit and pass the PE exam (plus an interview, in some...
Nice to hear opinions, and I do agree on the points that was raised. It is I guess a matter of engineering judgement, a conservative engineer would neglect the restraining effect of the brick, on the flip side the less conservative engineer desperate to have the smallest size as possible would...
Hey guys, if I have a concrete column that is abutted by brick walls on both axes can I consider my column to have zero buckling length in both directions since it is technically restrained by the brick walls from deflecting?
Like to hear your opinions on this.
Dear all, Please help me understand why the Mns (Moment due to slenderness of a non-sway column) is dependent on end moments of columns. Small delta ns is multiplied by larger end moments.
I believe that this should be a function of the eulers buckling load. However, as the equation ACI have...
Hi All, from what I have read, the main purpose of a over-sized/slotted holes are for ease in installation. I also heard that it can be used when a connecting member (ie one end of a simply supported truss) was designed assuming a roller support, the slot size being equivalent to the lateral...
Thank you for the response kootk. From your comment about the practice in North America over the ACI S/D ratio, it seemed that I shouldn't be too worried about the brittle finishes and the whole long-term deflection thing (as long I used S/D ratio in sizing my beams), since you guys seemed to...
Hi All, I have been doing some comparison with ACI and BS code. The span depth ratio values given in both codes are not far off with each other. Having dealt more with ACI, I understood that the span depth ratio only satisfies the requirement of immediate deflections and is only applicable for...
Hi guys, just wanna ask regarding a hypothetical question. lets say you have single frame with columns 30 meters apart. It is preferable to use pre-stressing on the beam for a better performance against gravity loads (unless a very deep beam is allowable, which in most cases is not). If a...
Hi everyone. Most of the references that I have read analyze a post-tensioned beams by assuming a pinned support. However, In reality PT beams are supported by columns. Lets say I have a PT beam supported by a 2 column frame. I believe that the PT force will cause the columns to experience a...
Hi Buggar, Thanks for your reply. May be it is a regional thing. I haven't seen a drawing showing a triangular lay out of rebars even though they are designed as as Truss-Tie model. Not much reply on this thread, may be i am alone on this boat.
For pile caps with three piles (3 piles forming a triangle, column on center), designed using strut-tie method or truss method, aren't the rebars supposedly parallel to the 3 tension chords of the strut-tie/truss model? which in this case would form a triangular shape on plan.
However, on most...
Hi guys, thanks for the replies. I see... so the max reinforcement does apply to splices, I have always been generous in sizing RC frames, so I was able to avoid these problem....until now that I am working with a person who has a preference for very slender elements. Any other cheaper...
Does the allowable maximum area of reinforcement apply to splice location of beams and columns? For example, if the code says max rebar area is 4%, and I use 3.9% as my design reinforcement and i would splice 1/2 of the total rebars on a certain location, that would result to a total rebar area...
Hi All thank you for the valuable comments. In my experience if I use thin concrete slabs (150mm>, for 3.5m span) and RC frames people would feel significant vibrations/shaking of the floor when a person relatively close to them would impose forceful impacts on the slab such as when a person...
Hi All,
In concrete design, does the allowable span depth ratio ensures that vibrations due to live load will not affect occupants? say for example I have 12' (3.75m)span continuous slab with a residential live load of 42psf (2kPa), if I use of 6" (150mm) thk slab would i feel significant...
Thanks for all your replies. The projects that I usually handle has a small floor area such as residential condo's, using core walls to resist lateral loads. the external cladding is to be designed by another engineer who specializes on facades.
The conclusion I've got from the comments here...
