Leaderboard

Assalam-o-alaikum! Dear colleagues! This forum is really a great platform for us, to share our knowledge and field experience with each other. Moreover, this forum can also help a lot in improving overall standard of technical know-how of our structural engineers, by providing them quality advice and guiding them to international standards of structural design and construction practices. IMO, this latter aspect is not only very important, but also our moral obligation as well as a national duty. But, this will be possible and practicable only, when more and more engineers join this forum, and contribute their knowledge and experience on regular basis. And, this is what this thread is meant for. However, we are probably missing an important aspect in our discussion, that can attract engineers to join and/or visit this forum more frequently. And, that is, replying to their queries early and more frequently. It is natural that a normal person is much more attracted to an early reply to his/her questions, rather than overall level of advice at a particular forum. On the other hand, no response to a query for a long time, will most probably disappoint the originator, resulting in lack of interest. What I am trying to emphasize is, that we (especially the moderators and senior/more experienced members) should NOT ONLY visit the forum regularly, BUT ALSO should reply the questions raised/queries made in various sections AS EARLY AS POSSIBLE. (I myself always try to act on this principle, in cases where I can help.) IMHO, this policy will not only attract more engineers, but will (later on) also build their confidence in this forum, as a major source of structural engineering knowledge and advice. Regards.

Juli! You have come up with a very good question. However, IMHO, you might not be able get reference to a single document to answer your question. The reason is that software design manuals are normally prepared to provide information on 'How to..' use various software commands (through various menu items, or command tabs), for the design of structural elements covered. Whereas, the analysis manuals cover the analytical theory on which the software is based. On the other hand, the example manuals provide methodology for using the software to perform some typical and common type of design tasks, highlighting salient features of the software and locations of ('where to find...') various commands used for the purpose. Unfortunately, however, these manuals DO NOT provide information on specifically 'When to..' use various commands or options. You will therefore have to adopt several approaches to get part answers of you 'When to' question. These approaches may include searching around on the internet, (and elsewhere) for related software training programs, tutorials and forums like this, to learn about the use of software for the situations other than those covered in software manuals. These are my 2 cents. Others members might guide you further, to more specific sources helpful in this regard. HTH Regards.

There are different recommendations for expansion joints in different books. I have seen no joints up to 200 feet in some text for RCC buildings. Anyways, you can do analysis for thermal differential case and see how much moment gets induced in your foundation. Visit the link below for information about carrying out thermal analysis. http://www.sepakistan.com/topic/1367-effect-of-temperature-changes-on-buildings/ Thanks

Hi Aung! One method of calculating the Area Springs, is with reference to 'Soil subgrade modulus, k' value. For example, if the k value of a soil is 120 ksf/ft and the area spring is applicable to an area of 1 square foot (sf), value of area spring will be 120 ksf/ft*1 sf = 120 kip/ft or (120 /12 = ) 10 kip/in. since k value can be calculated from B.C. value, IMHO your friend is partially right. Using the method given in Chapter 9 of 'Foundation Analysis and Design' by Bowles 5ed, if the soil bearing capacity is in ksf, approximate value of k = 36* B.C (answer is in ksf/ft). This, in case of your example with B.C. = 2.24 ksf, should result in an area spring value of k = 36*2.24 =80.64 kip/ft (= 80.64/12 = 6.72 kip/in.) HTH Regards.

Structural Dynamics by Mario Paz Dynamics of Structures by Anil K Chopra