EngrUzair

Good dig, Yaseen. A very useful discussion on the topic, along with a couple of latest references, is also available at the following link: http://www.sepakistan.com/topic/1628-rusting-on-steel-reinforcemnt/?hl=rust#entry4044 Regards.

Width of thicker mat portion should be sufficient to avoid 'punching'. This is sometimes taken equal to width of column strip, for simplified detailing, and is generally NOT larger than column strip. Following threads also contain some useful discussion related to slab/mat strips: 1. http://www.sepakistan.com/topic/1689-drop-in-mat-foundation/?hl=%2Bcolumn+%2Bstrip#entry4369 2. http://www.sepakistan.com/topic/1612-width-of-design-strips-in-safe/?hl=%2Bcolumn+%2Bstrip Regards.

Wa-alaikum-assalam. See Section 2.3 of the following document: CSI Shear Wall Design Manual (ACI 318-08) (http://www.google.com.pk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCcQFjAC&url=http%3A%2F%2Fdocs.csiamerica.com%2Fmanuals%2Fetabs_9.7.2%2FShear%2520Wall%2520Design%2FSWD-ACI-318-08.pdf&ei=q7ygVZb0KIn5ywON-7iICw&usg=AFQjCNEtuaJNcJdb2Gzvi2LEEqrRd-2n1A&bvm=bv.97653015,d.d24)

Type of moment resisting frame to be used, depends upon the seismic zone or category of the area in which the building is located, as permitted the applicable design code (UBC, IBC etc). In ETABS, you may select the 'sway' type for applicable moment resisting frame system (e.g., 'Sway special' for SMRF, and 'Sway intermediate' for IMRF etc.), from Preferences, BEFORE starting analysis of your structural model. Regards.

Following are the relevant ASCE standards: 1. Seismic Evaluation of Existing Buildings (ASCE/SEI 31-03) (http://ascelibrary.org/doi/book/10.1061/9780784406700 ) 2. Seismic Rehabilitation of Existing Buildings (ASCE/SEI 41-06) (http://ascelibrary.org/doi/book/10.1061/9780784408841) 3. Seismic Evaluation and Retrofit of Existing Buildings (ASCE/SEI 41-13) (http://ascelibrary.org/doi/book/10.1061/9780784412855 ) Whereas the following document is a pre-standard to ASCE 31, and may be useful in case of non-availability of above ASCE standards: Fema-310 Handbook for the Seismic Evaluation of Buildings, 1998 (https://www.wbdg.org/ccb/DHS/ARCHIVES/fema310.pdf) Regards.

Do you need general references to learn about the seismic evaluation and retrofitting concepts, or do you have a specific project to work on? If it is the later case, you may get a better advice if you could share some details (e.g. building type, structural system, material of construction, existing and required seismic strength categories etc. ) of your project. Regards.

You may use one or both of the following options, for this purpose: a. Increase slab thickness b. Increase depth of edge beams It is advisable, however, to recheck applied loading of relevant slab panel as well. Regards.

Refer to following threads, for a good discussion regarding mass source: 1. http://www.sepakistan.com/topic/1552-defining-mass-sources/?hl=%2Bmass+%2Bsource 2. http://www.sepakistan.com/topic/191-use-of-mass-source-command-in-etabs/ 3. http://www.sepakistan.com/topic/83-live-load-reduction/?hl=%2Bmass+%2Bsource#entry725 4. http://www.sepakistan.com/topic/1310-checking-analysis-result/?hl=%2Bmass+%2Bsource#entry2458 HTH Regards.

IMO, the only legal way to use your PEC number is to get employment by a firm and physically work for it, so that you could get the works executed as per standard engineering practice. According to my understanding, 'Selling your PEC number to a firm' means to indicate that you physically work for a firm, BUT ACTUALLY YOU DO NOT, and get paid for it. This action has following implications. Firstly, it is constitutes a lie that you work for the firm (whereas you actually do not). Secondly, by doing so, you indirectly certify (or the firm wrongly poses) that you are supervising the engineering works executed by the firm (although your are not) as required by PEC, and thus you are responsible for all wrong doings and defects in engineering works executed, for which your PEC number is being used. And, none of the above , is legal. Regards.

Muneeb, IMHO, your write-up would be very helpful for us all, if you could include following items in it: a. General concept and brief theoretical background (should be be very brief, and limited to practical aspects only) b. Reference to applicable design code & code clause c. A comprehensive example, elaborating step-by-step calculation procedure for the analysis and design of structural element being discussed manually. d. If possible, procedure of carrying out the example referred in para 'c ' above, using one of commonly used structural software (e.g., ETABS, SAP2000 etc.) Regards.

Here are a few links that would give you basic information, to start with the design of steel deck slabs: 1. Composite Steel Floor Deck - Slabs - Steel Deck Institute (http://www.sdi.org/wp-content/uploads/2013/04/SDI_ANSI_C_2011.pdf) 2. COMPOSITE SLABS AND BEAMS USING STEEL DECKING-Best Practice Guide-SCI Publication P300 ( http://smdltd.co.uk/wp-content/uploads/2013/02/SCI-Publication-P300-MCRMA-TP-No.-013-Best-Practice-Guide-REVISED-EDITION.pdf) 3. Composite Deck Catalog - ASC Steel Deck (http://www.ascsd.com/files/floordeck.pdf) 4. Metal Decking Design Guide - New Millennium Building Systems (http://www.newmill.com/pdfs/DeckDesignGuide.pdf) 5. Design of composite steel deck floors for fire (http://www.steelconstruction.info/Design_of_composite_steel_deck_floors_for_fire) If I remember correctly, there is a design example in composite floor design chapter of steel design textbook by McCormac, for calculating number and sizes of shear studs as well. Regards.

Dear colleagues, Polling for Elections of PEC (Pakistan Engineering Council) Governing Body for the Term 2015-18 are being held on 14th of June 2015 (day after tomorrow). Since the PEC is the controlling authority for all professional matters of engineers in Pakistan, it is certainly necessary that the people voted for running this organisation for the next few years, should have highest engineering degrees and vast professional experience. However, in addition, it is more important that they must be honest, have real urge and proven reputation of promoting engineering as a profession and being real practitioners of merit (in true sense) at each level within their areas of responsibilities. If we could select the candidates, having above mentioned qualities, it would certainly lead towards a better future for not only professional engineers but also for the Pakistan itself. Let us make contribution towards betterment of our beloved country, by selecting those people only, who really want to and can strive to develop Pakistan for making it a better country. Regards.

mhdhamood, Since you have increased the column thickness in one direction only, my proposed solution may or may not work in the present case. You will have to verify it, by treating the 'enlarged column neck' as the part of mat footing. In order to deal with punching shear, you normally need to increase shear perimeter 'bo'. This may be done either by increasing thickness of footing (more common and simpler), or by increasing the column size. I was talking about the first option (increasing mat thickness locally), whereas you are tackling the problem using second option (increasing column size). If you are interested in using locally increased footing thickness (instead of increased column size concept), you may do it easily in SAFE along with proportioning of required reinforcement. Regards.

mhdhamood, IMO, by increasing column dimension in-between the slab-on-grade and the mat foundation, you are actually increasing the mat thickness, which is otherwise needed to account for larger punching. I would (in case mat foundation is yet to be poured), treat the 'enlarged column neck' and the mat portion exactly beneath it, as a single mat (of thickness equal to sum of normal mat thickness and 0.5 m i.e thickness of 'enlarged column neck') and will provide reinforcement as per requirements of larger mat thickness. This concept is similar to what has been discussed in following thread: (http://www.sepakistan.com/topic/1689-drop-in-mat-foundation/ ) BTW... (1) How are you analyzing & designing the mat foundation? Using some software (CSI SAFE etc.) or manually? (2) Has the mat foundation already been poured, or is yet to be poured?

Load combinations depend upon the material design code (ACI, AISC etc) and the design method (strength design, allowable stress design etc). For example, if you are designing a steel structure, according to AISC LRFD, you wil need to use load combinations given in ASCE 7-10, Section 2.3. On the other hand, using AISC-ASD design, you will be adopting load combinations of ASCE Section 2.4. Moreover, how many load combinations are required, will depend upon the type of loads (dead, live, wind, snow etc), actually applicable in a particular case. The same principle is applicable for designs in Pakistan, based on ASCE 7-10 loads.

Check out the following link (http://en.wikipedia.org/wiki/Performance-based_building_design). The paragraph titled "Performance approach and prescriptive approach" may give you a brief idea about diffrences between the two approches. Internet search may provide you many more articles and documents dealing with the subject. Regards.

Heartiest congratulations Sir Umar, to you and all of your team. Thanks a lot for providing the civil & structural engineers (especially those of Pakistan), such a nice and great forum. May Allah Almighty bless you all.

BTW... Being a student, why are you needing the solution manual? To solve a class assignment?

Rasheed, If the only problem you are asking about is how to anchor the dowels, you may contact Hilti (as you have already been correctly advised by others) for necessary advice as well as execution of job. It is not a new technique, and is being commonly used all over the world, in connection with strengthening and retrofit of concrete structures. There is no harm in using it, provided it is designed and executed by a specialist firm (like the one mentioned above). You should however be careful that by relocation of column, column footing will become a bit eccentric, and may require rechecking to see it remains sufficient for the new situation or not. However, if you need a bit detailed advice, you will have to share some more details regarding your structure and extent of problem, e.g., - What type of structure it is? All RCC or partially concrete and partially structural steel? in what proportions? -Total number of storeys, - upto which level work has completed? - what is the actual bay spacing in both direction? - how many columns are causing problem? - What other options you are thinking of? Regards

In general, yes. However, be careful to check other requirements (especially minimum sizes & reinforcement of confining members, with reference to wall density) for confined masonry design, as given in the document referred in para 1-b of my previous post, and the following guideline (more recent): http://www.world-housing.net/wp-content/uploads/2011/08/ConfinedMasonryDesignGuide82011.pdf Regards.

Junaid, 1. If you go through the following threads, you will find several good references on the subject: a. http://www.sepakistan.com/topic/1652-load-bearing-structure-design/?hl=masonry#entry4141 b. http://www.sepakistan.com/topic/1326-seismic-design-guide-for-masonry-buildings/?hl=masonry c. http://www.sepakistan.com/topic/1313-modulus-of-elasticity-of-brick-masonary/?hl=masonry#entry2495 d. http://www.sepakistan.com/topic/1680-the-seismic-performance-of-rcc-frame-buildings-with-masonry-infill-walls/?hl=masonry 2. In case of a 3-story house, it would be better to use a framed or confined masonry structure, if the structure would be constructed in a location of seismic zone 2 or higher. Moreover, you would be requiring RC walls too, for the basement portion. Regards.

Assalam-o-alaikum, For calculating required area of a column footing, we normally use 'Dead+Live' load combination, for locations having no or very small snow loads comparable with live load. However, there are several hilly areas in Pakistan ( like Murree, and Gilgit etc), where the snow load is not only much higher than the live load (especially for single storey structures), but may also sustain on the roof for many days. My question (with reference to ACI 318-08 and ASCE 7-05 codes) is: What load combination we should use to determine required area of column footings, for these high snow fall areas? Whether 'Dead+Live', 'Dead+Snow' or some other? Would appreciate your opinion and comments, supported by relevant references, if possible. Thanks.

Umar, IMO, it is very nice that you have decided to start working on this idea. It would certainly be a demanding task, and as you have rightly said, would require a team to share knowledge and effort, for making this idea a reality. However, first of all, we will need to workout a detailed outline regarding what all has to be done, and in what manner. And, I am very keen to know what is your planning to take on this very important job. Regards.

I don't have the CRSI design guide. I had found its reference from google search. Unfortunately, haven't done such a structure myself. you may however try following sources as well for finding your desired information: 1. Check Reynold's Concrete Design Handbook. May be you could find some relevant material there. 2. Some technical documents are available at following link. May be you could find something helpful here: http://www.bubbledeck-uk.com/download.html 3. Article on Behaviour and analysis of voided concrete slabs (http://retro.seals.ch/cntmng?pid=bse-re-003:1989:57/1:57/2::743) 4. Finite element analysis and design of post-tensioned voided slab bridge decks (http://www.researchgate.net/profile/Jacobo_Diaz2/publication/220291881_A_computer_code_for_finite_element_analysis_and_design_of_post-tensioned_voided_slab_bridge_decks_with_orthotropic_behaviour/links/02e7e5370a7c5613ae000000.pdf?origin=publication_detail) 5. PLASTIC VOIDED SLAB SYSTEMS - APPLICATIONS AND DESIGN (https://krex.k-state.edu/dspace/bitstream/handle/2097/16874/CoreyMidkiff2013.pdf?sequence=1) 6. Presentation on Innovative Structural Slab Practices – Voided Slabs (http://www.concrete.org/Portals/0/Files/PDF/Webinars/Mota.pdf). It was sponsored by ACI/ASCE 421. Describes the CRSI design guide too, bot not in much detail. Good luck.