UmarMakhzumi

Rana, Lets do a simple experiment. How about we model a cantilever beam with frame/line elements and then model the same beam as shell elements and in both cases we just assign one reaction support. Thanks.

For pinned end, you have a built-in pinned option that you should use. For roller end, click the pinned option and un-check the horizontal reactions. So did it work? Thanks.

Hello Aadelaadel Fd, I can tell you how to do it in SAP2000. I don't have ETABS or SAFE installed but I hope that will help you since the interface for all three software is similar. In SAP2000, Go-to: Define>Load Pattern. Create a new load pattern and assign the type as temperature. The next thing to do is to select the frame member you want to apply this load, and go-to: Assign>Frame Loads>Temperature. That is it. Run the analysis and you are done. I have checked the results using an online website and they matched. Technically speaking, you should be checking all the limit states. So you can apply the temperature loads along with other loads to see what you get. You can also use judgement for the cases where you are confident. Please see ASCE 7 for details about what companion loads to consider with temperature load . Link to Online Calculator: https://www.engineeringtoolbox.com/linear-thermal-expansion-d_1379.html Thanks.

W/salaam.. Thanks for uploading the photos. Actually, the photos do give some idea, but I can't read the details. If you can upload a pdf copy of drawings, that would help me to see what is being presented. However, I will still try to answer your questions. The connection depends on pile type. If you are having concrete piles, you can just prolong the dowels from the piles into the raft/ pile cap. However, the length of dowels in the piles "must" satisfy development length requirements or your pile tension capacity shall be capped. If you are using steel piles, you need to weld dowels or nelson studs on top of your pile cap plate and provide enough development into the pile cap/ raft. Generally speaking, thick rafts (depends on depth of rafts and spacing of supports) are considered as rigid bodies for force distribution. Given that, you are fine assuming a pin support. A rigid raft/ mat foundation will produce only compression and tension so pin assumption would work. However, I will leave it to you to decide if your raft foundation is rigid enough to justify the assumption or not. Your photos aren't clear enough that I can read the details about the movement joint. Upload a pdf and then perhaps I can reply. I have seen your photos, but like I said, I can't read the details about how the the deck is supported by Pre-stressed beam, and how the beams are supported to the foundation level. Please upload a pdf version of drawing that shown all the detail. Also, when you post the pdfs, please also state that what section on the drawing relates to your question. I honestly couldn't find the detail of raft and secant connection and the 3 dowels. Please repost. Thanks.

Pattern Live Load would use a design moment greater than analysis moment. If design moment is less than analysis moment, analysis moment is used. I don't have ETABS but I do have SAP2000 installed. I can't open your model in SAP2000. Can you upload the .s2k file and perhaps I would be able to open it in SAP2K. Thanks.

ACI Code 13.7.6. provides answer to your question. The program would consider design moment using PLF only if the value of design moment is > than analysis moment, else it would just design for analysis moment. Thanks.

Hi Oscar, You might wanna try looking at https://nees.org/ . I have searched but couldn't get a freeware. NEES might have something for you. Good Luck. Thanks.

W/salaam.. Can you please post drawings or snapshots of how this looks like.. You can post your structural framing. It would be easier to reply once the information is at hand. Thanks.

Taylor Devices are the market leaders in dampers. They used to do it for air crafts but then started it for buildings too.. Find their story.. It is very motivating and inspirational. Thanks.

1- Can you please attach your design summary results. PDF would do. 2- Serviceability requirements are different for different cases. For lateral case, if seismic is governing, we do use factored load combos to check inter-story drift. See the post here: http://www.sepakistan.com/topic/1341-ubc-seismic-drift-limits/ If you have wind governing, you need to use the appropriate wind load.. Generally, building codes recommend using 1 in 10 max wind for serviceability checks and 1 in 50 max wind for design checks. Thanks.

W/Salaam.. There is a lot that happens during shrinkage.. PCA has a good article on their website; see attached. Thanks. Concrete Shrinkage.pdf

You can google Taylor Devices to get the working link: http://www.taylordevices.com/ Thanks.

What suprises me is that the foundation doesn't has any reinforcement. It should have atlease something as it will bend in flexural while distributing load from the columns to the ground. Embeding steel columns in concrete can be done like EngrUzair said, however noticing that you mentioned absence of shear studs, I think you are more interested in calculating the max tension the embeded steel column can take before it breakouts of the concrete. You can use ACI Appendix D to calculate the concrete breakout capacity of the embeded column to see how much tension it can take. Shear shall be transferred by bearing contact of column to the sides of embeded foundation and by friction on the underside of baseplate. The check for bearing contact of column to the side of embeded concrete foundation against lateral load will also give you the maximum moment you can develop based on embedment. This would be conservative as your baseplate(if rigid enough) can help increase moment resistance too (which you can ignore to be on the safe side). All you need is a free body diagram. Thanks.

I would suggest a follow up with a manufacturer. http://taylordevices.com/ http://www.teratec.ca/ This sounds interesting. Let us know how it goes. Thanks.

Rana, 1) Yes. See attached: Seismic Time Histories.pdf 2) I am not really sure about how to answer that. Why would you have to go in non-linear domain when you are doing a linear time history analysis? Thanks.

You may find the following topic of interest too: http://www.sepakistan.com/topic/1545-what-would-be-the-proper-choice-between-shell-and-frame-for-modelling-12m-x-06m-vertical-element/?p=3577 Thanks.

Since the length of basement wall would likely to be much longer when compared to a conventional shear wall, lateral shear resisted / unit foot of basement wall would not be significant. Critical case for basement wall (generally speaking) should be lateral load due to earth + any increase in that lateral load due to earthquake. This load would be perpendicular to wall. Also, have a look at the following topic (there are 5 threads) as you may find them interesting: http://www.sepakistan.com/tags/forums/Highrise%2Bwith%2Bbasements/ Thanks.

There are different ways in which your question can be answered. I will try to explain how existing code provisions team up to satisfy statement posted above or how the analysis steps taken by a Structural Engineer work to meet the 21.1.1 Clause. Here is the response in-terms of code clauses enforcing integrity: 1) The seismic-load-resisting system must have sufficient strength to limit ductility demand. R implies level of accepted ductility but code also imposes maximum period to be used for strength check T< CuTa. The reason: Over-estimate of period results in lower required strength. This indirectly puts a requirement for minimum strength. So code is enforcing minimum strength. 2) Similarly, the seismic-load-resisting system must have sufficient stiffness to control drift. Drift control indirectly puts a requirement for minimum stiffness. Code wants you to have minimum stiffness. 3) Critical elements are required to be designed for amplified load. (Use of Omega for collectors, elements supporting discontinuous frames etc. See AISC 341 for more detail). This is damage control. 4) The seismic-load-resisting system must have sufficient integrity to prevent separation of elements and components. This is satisfied by ensuring deformation compatibility and designing all elements for tie/ anchorage forces. 5) Stability is satisfied by requiring the seismic-load-resisting system to have sufficient strength and stiffness to ensure that second order effects are not significant. Second order check is performed. See equation below. This ensures that even under large seismic displacements, we have sufficient ability to resist seismic load. When doing your structural analysis to code/ ASCE 7, you are indirectly striving to achieve integrity that would satisfy much higher forces than what you have designed for. The above points just provide summary of some of the checks built in the code to ensure that. Thanks.

You can design it as propped cantilever. The presence of top floor and foundation would enforce one way bending (Case of a square panel with two sides having stiff supports) For areas where you don't have a top floor, you can use the information provided in the link below to design your wall as 2 way slab panel. http://www.sepakistan.com/topic/16-rectangular-concrete-tanks/ Thanks.

Hilti anchors can be used in PCC. However, you need to check the capacity of the anchor against applied load. Assuming 4 Hilti Anchors (150mm Embedment) are used for T-Support, at a spacing of 300mm c/c, with a support heigh of 3m the max factored moment at the base would be: M= (1.5*3m*3kN)= 13.50 kNm. Tension/ 2 Anchor Bolts= 13.50kNm/(0.3m) = 45 kN. Max Tension on a Hitli Anchor= 45/2 = 22.5 kN ignoring vertical load. A 150mm Embeded Hilti anchor with reasonable edge distance should be able to take this load. However, you are advised to check the capacity of 150mm anchor against max tension by looking at the product chart. Thanks.

That is the normal case when designing braces. KL/r checks are made to ensure that the brace will always fail other than buckling. Thanks.

You should always consider stairs and ramps in your structural model. There is also a discussion about it in Pauley and Priestley if I remember correctly. Also please make sure you design your stairs for the load they are attracting. Thanks.

Shear walls can be designed the same way beams are designed.. You have the cross-section, apply the moment and calculate the steel. I have designed some masonry shear walls back in the day(during university assignments) using same approach. You can find examples too in text books. There are some extra checks other than that the process is simple. Consider axial and shear forces too.. Thanks.

Where did you get this formula? See second link below for how to establish relationship b/w plastic moment and elastic moment and how to find max load. 1) Page 269- https://books.google.ca/books?id=df7R9rT3nmUC&pg=PA269&lpg=PA269&dq=plastic+moment+capacity+of+fixed+end+beam&source=bl&ots=G_6gbccs2A&sig=4Sk9vDgG9Zid2bT3ubiYz195Bys&hl=en&sa=X&ei=0t-dVbaJHML1-AGTs6iYBQ&ved=0CCIQ6AEwAg#v=onepage&q=plastic%20moment%20capacity%20of%20fixed%20end%20beam&f=false 2) http://www.steel-insdag.org/TeachingMaterial/chapter35.pdf