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Mechanicos Z
Branch Unspecified
10 Jul 2017
Column design with eccentric beams
Hello everyone,
I am designing a 2storey RC frame house according to EC2 and EC8 and three of the columns are impossible to design.
Two of these columns 13 and 20 are of similar configuration, please see image below.
They have eccentric beams connected perpendicular to the column one at each end.
all columns fail at seismic load combinations
No matter how much shear reinforcement i add or how much i increase the column section it still fails at seismic combinations.
I tried researching why these 3 columns fail and i found out some excessive shear forces are generated at the seismic combinations reaching up to 1000kN in the strong axis of the column.
I think this is way excessive considering the fact that this is just a 2storey house and in fact the total base shear of the structure (in the design spectrum acceleration) is only about 900kN.
So what do you guys think?
![[IMG]](proxy.php?image=http%3A%2F%2Fres.cloudinary.com%2Fengineering-com%2Fimage%2Fupload%2Fv1499691790%2Ftips%2FScreen_Shot_2017-07-08_at_23.16.24_cx9kdz_zz69rg.png&hash=05f9e42fb987008e59e74b9ccc02d1c1)
![[IMG]](proxy.php?image=http%3A%2F%2Fres.cloudinary.com%2Fengineering-com%2Fimage%2Fupload%2Fv1499545363%2Ftips%2FScreen_Shot_2017-07-08_at_23.18.28_xb45nx.png&hash=c54fa29571e5656ed7802a297e87f7ff)
![[IMG]](proxy.php?image=http%3A%2F%2Fres.cloudinary.com%2Fengineering-com%2Fimage%2Fupload%2Fv1499545375%2Ftips%2FScreen_Shot_2017-07-08_at_23.18.39_idsieh.png&hash=129337029a267fa97ef853642a46a470)
I am designing a 2storey RC frame house according to EC2 and EC8 and three of the columns are impossible to design.
Two of these columns 13 and 20 are of similar configuration, please see image below.
They have eccentric beams connected perpendicular to the column one at each end.
all columns fail at seismic load combinations
No matter how much shear reinforcement i add or how much i increase the column section it still fails at seismic combinations.
I tried researching why these 3 columns fail and i found out some excessive shear forces are generated at the seismic combinations reaching up to 1000kN in the strong axis of the column.
I think this is way excessive considering the fact that this is just a 2storey house and in fact the total base shear of the structure (in the design spectrum acceleration) is only about 900kN.
So what do you guys think?
Mechanicos Z
Branch Unspecified
13 Jul 2017
nothing?
Ok then i will post my progress up to now and the advice i received from other engineers in other forums.
1. The capacity design shear value of 1000kN that i get is way too high - checked it with hand calculations, now i need to double check this with another software just to make sure.
2. I was also advise that i may consider some elements as secondary which dont need to be designed according to EC8. Also he geometric constraints by EC8 do not apply to secondary members. which would - the doubly eccentric column are not allowed by EC8
Ok then i will post my progress up to now and the advice i received from other engineers in other forums.
1. The capacity design shear value of 1000kN that i get is way too high - checked it with hand calculations, now i need to double check this with another software just to make sure.
2. I was also advise that i may consider some elements as secondary which dont need to be designed according to EC8. Also he geometric constraints by EC8 do not apply to secondary members. which would - the doubly eccentric column are not allowed by EC8
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