UmarMakhzumi

Hi grozni, You best bet would be to a get a book about the subject. Is your problem resolved or still outstanding? Thanks.

The foundation should be deep enough that it rests on a competent strata. If you have a geotechnical report, the geotechnical engineer would have made a recommendation about minimum depth in it. If you don't have a geotechnical report, generally it is kept below frost with assumption that the strata underlying the raft is competent. Thanks.

I believe these values can be interpolated for a different probability. I know a tool for Canadian Seismic Values that does that. Anyway, I think if design life is 60, then the values should be used for 60. It would be interesting to know if someone has done this kind of interpolation and is willing to share info here.

Links can be used to model any structural element. To give you an example, for the case of analysis of structural steel supporting pumps/ compressors etc, piles and soil impedance (damping + stiffness) needs to be provided in SAP2000. So, a lot of engineers use another software called DYNA to get those values and instead of support provide link with properties obtained from DYNA to create an analysis model that reflects the actual condition. This is just one use of link. For the above case, links might have been used to provide support properties that could not have been modelled directly. I assume the link represent some kind of soil structural support response but that is my guess as I am not aware of tunnel design. Coupled stiffness means the response of the link would consider stiffness values together in the direction specified If these are metric units, then the properties are defined for 1m and 1m^2. Check this out for further details: https://wiki.csiamerica.com/display/kb/Link Thanks.

This is useful information. So, do you also convert your seismic, wind and snow loads (environmental) to the probability of 1 in 60 years? Thanks.

Here is what I do: For Stiffener Against Beam Compression Flange; Force in Stiffener = Fst Compression = Difference between flange force and bearing resistance provided by column web. For Stiffener Against Beam Tension Flange; Force in Stiffener = Fst Tension= (Mf/ db) - Tr Where, Tr = 7* Phi * tc2 * Fyc I should have talked about the stiffener against tension flange in my earlier reply. Anyway, these are the only two checks assuming that your column is at-least Class 2 or Class 1. There are other checks if its Class 3 and Class 4. Generally Class 3 and 4 sections are not provided as columns so all good. This is all based on Canadian Code S16. Thanks.

Please see these topics: http://www.eng-tips.com/viewthread.cfm?qid=347923 http://www.eng-tips.com/viewthread.cfm?qid=1734 Thanks.

W/s Imran, It is very hard to say if your FYP would help you in securing a job but one thing that is for sure, is that you will get skills like assessing an existing structure, doing base isolation and information about seismic codes and the response of a building to a seismic event - such skills would help you wherever you go. I am not aware of use of base isolators in Pakistan, there might be sensitive military installations where these are being used but I don't know if the market is really big for that and there is immediate need for people having that experience. But like I said above, you will get a skillset that any structural firm in Pakistan would value provided you do your project correct and develop understanding of what you are doing. Thanks.

Sorry by end plate I meant the plate that is connecting the beam web to the column. More specific checks for your case would also include: 1) The column web needs to take the force of M/d transferred by beam flange. The minimum thickness of the column web should be greater than wc >1.9*M/(db*dc*Fy) where dx is the depth of beam or column as per subscript. If the web thickness is not enough, the panel zone would require diagonal stiffener. The equation is based on Canadian Code S16. 2) Bearing resistance of column opposite to beam compression flange. If you do this check, you need not to provide any stiffener in the connection area if the checks passes. Thanks.

Groszni, What you did is good. You need to check the following as well: 1) Geometry Checks which include End Plate Thickness, Bolt Edge Min and Max Distances, Bolt Hole Pitch. 2) End Plate Tension and Block Shear along vertical line of bolts (You might have already checked it). 3) Check beam web shearing strength at weld. Hope that helps. Thanks.

Salman Ch, Thanks for your comment. Pile cap would only behave as a deep beam if distance between ratio of slab thickness to distance between piles is more than whatever is required by code for deep beam action. I live in Canada and here if the shear span to depth ratio is less than 2.5, deep beam action can be considered. If not, it is a normal slab. ACI has a different limit. So yes, it may be a deep beam or not, but same would be applicable to a slab if your columns are too close. Anyway, thanks for highlighting that as now the clarification may be useful for someone who isn't aware of this This is standard practice and there can be different reasons for not considering soil springs. For example, in North America, heave is a big problem and generally pile caps have a layer of void form below them. Void forms are compressible and analysis should never consider soil springs for that reason as there would never be a hybrid action in that scenario. Also in typical cases stiffness of pile group is >> than soil so it doesn't make sense to put soil springs. Thanks.

WA Rifat, Is the soil sandy or cohesive? Thanks.

For accidental torsion, podium would share a common diaphragm so you need to consider it as one but levels above podium where buildings are isolated, you should consider individual buildings and individual drift limits. You can search the forum. There is an ETABS manual posted sometime earlier on high rise buildings design. You can let ETABS do it for you. There is a tutorial available about it as well. See first tutorial here: https://www.csiamerica.com/products/etabs/watch-and-learn Thanks.

Please see this response: Thanks.

Please get your petition ready and we will support you through our forum. Thanks!

Hira, I found the following: Technical Manual for Design and Construction of Road Tunnels — Civil Elements Guidelines for the Design of Tunnels - ITA Working Group.pdf Structure and Construction Examples of Tunnel Reinforcement Method Using Thin Steel Panels.pdf http://structuraldesignbs.blogspot.ca/2015/11/tunnel-design.html Link to Source: Google Search What I would suggest is that find two or three good books on tunnel design and ask your employer to buy them and use them as books have a lot of solved examples. Thanks.

Engr. Wael, The best approach that I have seen is to apply slab loads in ETABS directly on Beams. For that you will need to manually resolve slabs forces to beams which doesn’t take much time. The upside of this approach is that your model is very clean and without flimsy meshing errors. That is the recommended approach based on my experience. You can always later draw slabs in SAFE and design them there. Now regarding why did auto-line constraint fixed your error; I don’t exactly know the answer to that. CSI might be able to answer this question. You can ask them if you have a licensed software and it would be great if you can share the response here as well Thanks.

How can we contribute to this noble cause?

Here is the answer from CSI Wiki. I have also highlighted the portion of response that I think is most applicable to your case. Thanks.

For example, if you have used a single angle for a brace, then because of the eccentricity of the angle to the connecting beam, you will have a moment Mux in addition to axial load and you will need to do beam column capacity check for this member. There wouldn't be any Muy. Thanks.

You should be able to have more than one pile under the pole. The pole dia is 1.8m so that means you have 1.8m of real estate to do the piles the least. From a structural stand point, your pedestal would be > than that to accommodate for anchor bolts and to allow them to develop. Even if your Pedestal is 2.2m (slightly larger), you can easily have 324 or 200 mm dia pies at 1.8m circle as long as they are spaced greater than 3D. You can also go for pre-dill/ bore at the site to allow for deeper piles. I am working on some vessel equipment where there is sandstone and we are pre-drilling to get the desired capacities. Get recommendations for geotech about it. Also, predrilled piles aren't great at tension so have that discussion with your geotech consultant. I would rather have a larger pedestal under the pole, say 2.5 m (if possible) and space my piles under it. The Pedestal would also act as pile cap too and numerous piles would transfer your load in tension & compression couples and allow you to meet limit states. Hope that helps.

@waqar saleem, @EngrUzair, @BAZ might be a good resources to start. I don't live in Pakistan so can't do anything directly but please touch base with these three and then lets see where it goes from there.

Yeah that is correct. Restraints strength is Axial Capacity And Moment Capacity Interactiom based on code. That is what would likely govern. Thanks.

Looks good. You can also have a corbel on the underside of the beam as part of column. That would make load transfer more smooth and make the connection redundant (If corbel fails, you still have the beam). Thanks.

Dear miqureshi77, Are you flexible on work location or would you prefer working in Karachi only? Thanks.