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Hello Everyone, You might have seen a lot of buzz on social media about Pakistan Engineering Council Elections 2018. It is great that candidates are coming forward with manifestos and idea to bring PEC up to speed. I am writing this post to highlight that please make sure that you vote in these elections and do spend some time doing little research on the person you want to vote. Chairman PEC is a very prestigious position and if we can get the right person in, a lot can be changed for current and prospect engineers. What do you say? Thanks.

Hello Hafsa, Instead of adding negative value in mass source, why don't you change the value of load. I mean enter the load as negative and don't change the sign in mass source. Thank you, Regards, Areeb Ahmed.

Hello, Well as you said as per dimensions of the plot that X direction is smaller, it becomes necessary to add shear walls in X direction as it is critical in that direction during seismic analysis. Regarding the system you have asked you can provide core wall around the lift and staircase and columns, however you have to see which zone the plot is located. if it is till zone 2B then i think this system is acceptable as you can have high response reduction factor value. Also even if you are using walls you can reduce the size of walls in terms of thickness as well as length as you go to higher stories. This reduction also should be done in a reasonable manner. There is also another system of haunch girders which could be economical and can be used in zone 3 or 4. There are many systems also like frame tube system or shear wall frame system etc. which could be economical. Thankyou, Regards, Areeb Ahmed.

Hello Fatima, Well the procedure you have explained is correct for finding out the shear strength of columns, thereby ultimately finding out the story strength. Still I find it cumbersome and we have direct formulas for knowing the shear strength capacity of wall or column thus rather than going by the method of flexural strength we can directly find out shear capacity of wall/column and find out story strength. Thanks for the update regarding the method used by you. Although cumbersome something new to learn today.😃 Regards, Areeb Ahmed

For Weak Storey check If columns are flexure controlled, the shear strength is the shear corresponding to the flexural strength. (Ref: http://www.iitk.ac.in/nicee/IITK-GSDMA/EQ06.pdf) So I used to calculate flexure strength (Flexural capacity) of column section and then divide this by the length of column to find the maximum shear it can resist before flexure failure may occur. This will give me the shear strength of an individual column. then adding these all will give storey shear strength. its like adding moment at top and bottom of the column to get the shear force of the column. (the way usually people do to calculate internal forces manually) I dont have exact reference, but i will research on it and will let you know.

Hello Zain The method which you have mentioned above is for finding out whether the system has soft storey or not. You can use the method mentioned above or ETABS latest version directly gives the stiffness for each storey thereby its easy to find out whether the system has soft storey irregularity.