EngrUzair

Structural design methodology is basically same for both in-situ and precast construction. the differences are mainly in member end conditions and methods of construction. In case of precast construction, you will need to cast members somewhere else, and subsequently transport them to actual construction site. In this case, you will have to take care that your members do not get overstressed because of mishandling during transportation & placement. On the other hand, in case of in-situ construction, you will pour concrete at the actual site, with or without changes in member end conditions, depending upon slab support type, adopted in design. In this case, you will need to keep your deck fully supported till the concrete is set, and able to sustain design loads safely. Regards.

Here are a few basic references, to start with: 1. Design Guide for Voided Concrete Slabs, available from CRSI (https://netforum.avectra.com/eweb/shopping/shopping.aspx?site=mycrsi&prd_key=e1a1822d-c884-4c86-ba6d-2f4e41385a9d) 2. Design of Highway Bridges - An LRFD Approach By Barker and Puckett 3. PGSuper software for the design, analysis, and load rating of precast-prestressed girder bridges, according to AASHTO LRFD specification (http://www.pgsuper.com/content/what-pgsuper) 4. Voided slab design, using PGSuper software: (http://www.pgsuper.com/content/voided-slab-design) In addition, you may find many other resources for the 'voided slab design', using a smart search on Google. HTH Regards.

And, to complete the record, here is the list of building codes for other countries (outside USA), which are also based on ICC codes. the regional Caribbean Building Standards the Residential Building Code for Mexico the Haitian National Code the Honduras Building Code Jamaica’s construction codes; and Georgia’s building safety codes. [Reference: ICC fact sheet 2014; http://www.iccsafe.org/newsroom/Documents/factssheet.pdf] Regards.

A little update: An alternative for "SEFP Consistent Design CODE" proposed above, may be the adoption of the design and loading codes referenced in the IBC (International Building Code), with certain essential changes regarding environment loads (e.g., Wind, Snow, etc) pertaining to Pakistan. Similar practice has already been in vogue in some countries, e.g., Abu Dhabi has recently adopted a building code, based on IBC 2009. Whereas, 2007 Saudi Arabian building code is also based on IBC. There might be some other countries, following this practice, too. Refer to following link, for further details in this regard: http://skghoshassociates.com/SKGAblog/viewpost.php?id=37 Regards.

@Rana, My point of view, is as under: 1. When we select & adopt a structural software, we believe that it works correctly at least for basic design-related calculations; both the structural analysis i.e., computation of member forces and moments etc, and proportioning of members i.e., sizing of members and determination of reinforcement. 2. Now, if we believe that the software is performing correctly for the analysis part (which is not only most important and a harder calculation), will it be logical to say that design results of software (Which are a lot simpler and easier to calculate) are incorrect, WITHOUT verifying it manually? In simple words, if analysis results of ETABS (or any other structural software) are acceptable to me, I will not object to its design output merely because I 'feel' that it is giving excessive reinforcement or erroneous results, UNLESS I check them manually and is prove them wrong. 3. In the present case, if we are sure that all other calculations done by ETABS (including all the analysis and other design output) are OK, I see no reason for believing that the software is giving incorrect reinforcement (both in display as well as design summary) for the columns - the most critical members of the structure. 4. As such, IMHO column reinforcement (or other design results), displayed in graphic output or shown in design tables, SHOULD NOT be ignored ordinarily, without any soild reason. Regards.

Hi Kemal, Welcome to the forum. Nice to see you here. I have been to Turkey for a few days, several years ago, in connection with collection of data for one of my projects. As such, I have a bit deeper love for turkish people, as compared to many others. Yes. You are right. We mostly use ETABS and SAP2000 here in Pakistan, although some engineers us STAADPro as well. By the way, what do you mean from 'different methods' for high buildings? Regards.

Junaid, As sameer has said, by default ETABS calculates reinforcement value at three locations along column height - at location 0.00 (start of column at floor level), at mid-height , and at top face of column (i.e., at base level or soffit of upper floor beam). According to my understanding, column reinforcement is designed for the largest of load effects at these locations. IMO, you should check your model carefully. If you have applied 'frame end offsets' properly, and these are actually being applied by the software to the model (as may be verified from the moment diagrams for the load combinations involving earthquake loading for concrete frame structures, and wind load for steel frame structures), your reinforcement location values should be as given in above (with column height taken upto soffit of upper level beam). If OK, you SHOULD NOT ignore the reinforcement value at column location 0.00 in such a case. It will, in most of the cases, be the controlling value for the column. If in doubt, check the column reinforcement design manually for the suspected locations, using applicable load combinations, to see whether the reinforcement provided by the software is OK or not. You should ignore the program provided reinforcement, only when you are sure that there is really some error in program output. Regards.

My suggestions are as under: 1. Some research has already been done and more is being carried out on various aspects of beam-column joints, both nationally as well as internationally. Searching the internet for the research papers on beam-column joints, might give you some new idea to include in your FYP. 2. You may propose the use of fiber reinforced polymers (FRP) composites for retrofit purpose in your FYP. Although very efficient for seismic retrofit, these are costly materials. Since these are imported materials. Therefore, you will have to check their availability locally, before proposing their use in your project. Regards.

Assalam-o-alaikum! Through internet search, as far as I remember. Regards.

waqar, In case of SAFE 12, relevant information is located in 'PROGRAM CONTROL' area of the model text file. The data to be modified here would be for 'ProgramName', 'Version', and possibly 'ProgLevel'. I haven't come across the SAFE v14 files yet. However, the process for SAFE 14 should be similar to that for SAFE 12, with some minor changes, if any. Regards.

Mohammad, Width or extent of this thicker area will generally depend upon the following: a. Punching shear value. Width of thicker area in this case may be less than standard width of column strip in the relevant direction. For discussion regarding slab or mat strips, you may refer to the following thread: http://www.sepakistan.com/topic/1642-slab-design/ b. Site requirement e.g., sloping area where mat is to be provided at two different levels. Regards.

Mohammad, See the attached pictures, taken from sample SAFE model: (Note: Middle strip, shown in the pictures in- between the two 60 cm thick strips, is 100 cm thick.) Regards.

Load combinations used for column design are the same, as used for concrete frame design. For the designs conforming to ACI 318-08 or ACI 318-11, relevant load combinations are available in chapter 9 of the relevant code. However, for the concrete column designs compliant to ACI 318-14, the applicable load combinations have been provided in chapter 5 of the code. Regards.

I agree with Umar. Normally, we provide a uniform minimum thickness of mat everywhere, except under columns carrying heavier loads, and requiring larger mat thickness due to punching shear requirements. Moreover, You may model you mat in SAFE (and possibly in other foundation design software as well), providing different mat thicknesses at desired locations. Regards.

What are your questions?

batoul, In case you follow American Design codes for your designs, you may use following references, among others: 1. Specifications regarding design of composite members are given in Section I of Part 16 in AISC Steel Construction Manual, 14e, 2011. 2. Several examples of design of composite members (including composite columns), have been provided in Chapter I of AISC Design Examples version 14.1, that can be downloaded FREE OF COST from the AISC website, using following link: http://www.aisc.org/WorkArea/showcontent.aspx?id=33520 3. 'Structural steel design' book (5e) by McCormac has a complete chapter on composite columns, besides a chapter on composite beams. Regards.

aadel, AFAIK, for this type of conversion, you will need text file (24414.2.$et) of your model. Required process should be as under. 1. Open text file of the model in Notepad. 2. In 'PROGRAM INFORMATION' portion, make following changes: a. Change the PROGRAM option to "ETABS", INSTEAD OF "ETABS 2015" b. Change the VERSION option to "9.7.4", INSTEAD OF "15.x.x" 3. Save the file as 'All files', with extension '.$et' 4. Import the newly created text file into ETABS 9.7.4. 5. Since ETABS 2015 contains a lot more new features (not available in older version 9.7.4), you will certainly see a number of error messages during this import, indicating the inability of program to import data regarding newer options and ignoring of the relevant commands. This is normal for imports of NEW version files, in Older versions of programs. Just keep on pressing 'OK' button on these messages, until import process has completed. 6. Save the imported file as ETABS 9.7.4 model (.edb) file. Note: You must be aware that the model file, imported by ETABS 9.7.4, would however not be same as the original ETABS 2015 file. Rather it would be deficient in several respects, as may be clear from the error messages displayed during import in older version. Therefore, you will have to check the model in detail, to see which respects the model is OK, and in which it is not. I don't know what an 'mdp' file is, as such I am unable to comment on export of such files in ETABS 2015. Regards.

Wa-alaiku-assalam! Here are a few start points: 1. ACI 318-08 sections 11.11.6 and 13.4 deal with openings in slabs. Openings in structural diaphragms are discussed in section 21.11. 2. Effect of openings in slabs on shear strength, has been elaborated in chapter 16 (Page 16-11) of PCA Notes on ACI 318. Whereas, effect of openings on flexural strength has been explained in chapter 18 (pages 18-6 to 18-8) of PCA Notes. 3. Have a look at the following documents: a. https://www.structurepoint.org/publication/pdf/PCA-Concrete-Floor-Slab-Openings.pdf b. http://cement.org/buildings/tech_note_floor_openings.pdf c. http://mak.ac.ug/documents/Makfiles/aet2011/Tayebwa.pdf d. https://pure.ltu.se/ws/files/30966569/LTU-EX-05200-SE.pdf 4. You may model a slab in SAFE software and experiment by providing openings of different size, and at different locations (with respect to slab edges), to see effect on variation of stresses around the openings, in order to decide the amount and placement of required reinforcement. Regards.

Moderators, Would you like to share your views on the subject, keeping in view the legal requirements, applicable to the regions you are working in? Regards.

Dear akhtar, Unfortunately, I have done none of them. In fact, after completing B.E. from Pakistan, I did my masters from USA on government scholarship. And, as per terms & conditions of scholarship, I had to return to Pakistan, immediately on completion of my studies. As such I had no time even to apply for FE exam alone. I however wish to be able to do both of them, and preferably the SE exam if possible. Regards.

You are welcome. Best of luck in your chosen field. Regards.

batoul, Yes. You may attach your model here, if you want to. You will need to use 'More Reply Options' button, given below the 'Reply this topic' window, to view the option for attaching your file. Regards.

Dear Abdur Rasheed, Refer to the following thread, for having a valuable advice on career selection: http://www.sepakistan.com/topic/1605-design-job-or-field-job/ Regards.

Wa-alaikum-assalam. IMO, 'footing' option should be used in case of isolated & combined column footings, as well as strip footings (supporting either wall loads, or a column line consisting of three or more columns). On the other hand, 'Mat' option should be adopted when a single footing is to be designed to carry the loads, supported by a numer of columns or walls, oriented in different directions. Regards.

Dear Mohammad, Yes. It is the normal practice, in case of combined footings. Application of this concept is available in RC design text books, based on ACI 318 code. For instance, 'Design of concrete structures', 14e (2010) by Nilson (Example 16.3) and 'Reinforced concrete -mechanics & design, 5e (2009) by Wight & MacGregor" (Example 15-4), among others. Regards.