www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

Tractive and Breaking force in Seismic Condition

 
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Dams and Bridges
View previous topic :: View next topic  
Author Message
swapnilgmc
SEFI Member
SEFI Member


Joined: 15 May 2012
Posts: 3
Location: England

PostPosted: Thu Mar 23, 2017 5:21 am    Post subject: Tractive and Breaking force in Seismic Condition Reply with quote

Dear Sir/madam,
While designing the Road/railway bridges in seismic condition, the effect of Breaking/Tractive effort shall be considered or not ? and where the codal provision is mentioned.
Kindly guide in this regards.

_________________
Thank you
Back to top
View user's profile Send private message
bkballa
SEFI Member
SEFI Member


Joined: 29 Nov 2010
Posts: 11

PostPosted: Wed Mar 29, 2017 8:34 am    Post subject: Reply with quote

Dear swapnilgmc,


Vehicle load need not be considered (or only 20% vehicle load need to be considered) when the direction of earthquake is in x-x direction (along the traffic). Hence, no need to include braking force (or only 20% braking load).
When earthquake is in y-y direction, I use to take all vehicle load and all braking load.
Hope this helps.


Biswa Balla


PS: Plz confirm whether no live load is taken or 20% is taken in EQxx.

Back to top
View user's profile Send private message
swapnilgmc
SEFI Member
SEFI Member


Joined: 15 May 2012
Posts: 3
Location: England

PostPosted: Tue Apr 04, 2017 5:16 am    Post subject: Reply with quote

Thank u so much sir for your kind guidance
_________________
Thank you
Back to top
View user's profile Send private message
msazarudhin
SEFI Member
SEFI Member


Joined: 06 Apr 2015
Posts: 5

PostPosted: Wed May 10, 2017 11:13 am    Post subject: Reply with quote

As per (last) note in Clause 211.5 of IRC:6, "the structure under the fixed bearing shall be designed to withstand the full seismic and design braking/tractive force". And so the braking (not breaking ) force should be taken in seismic condition. i.e., braking force of 20% of vehicular load.
Back to top
View user's profile Send private message
bkballa
SEFI Member
SEFI Member


Joined: 29 Nov 2010
Posts: 11

PostPosted: Wed May 10, 2017 4:24 pm    Post subject: Reply with quote

msazarudhin
Posted: 10 May 2017 12:13    Post subject:

As per (last) note in Clause 211.5 of IRC:6, "the structure under the fixed bearing shall be designed to withstand the full seismic and design braking/tractive force". And so the braking (not breaking ) force should be taken in seismic condition. i.e., braking force of 20% of vehicular load.

Dear msazaudhin,

You are right about the note on cl. 211.5 of IRC:6-2014. However in cl. 219.5.2 of IRC:6 states:


219.5.2 Live load components
i) The seismic force due to live load shall not be considered when acting in the direction of traffic, but shall be considered in the direction perpendicular to the traffic.
ii) The horizontal seismic force in the direction perpendicular to the traffic shall be calculated using 20 percent of live load (excluding impact factor).

This implies that you do not need to take braking/tractive force in case of EQxx (as no live load is present) and need to take 20% of braking/tractive force in case of EQyy.

,where EQxx = earthquake in x-x direction (ie direction of traffic); EQyy= earthquake in y-y direction (perpendicular to the traffic).

Is there something I missed regarding EQ and live load & braking force?

Biswa
Back to top
View user's profile Send private message
msazarudhin
SEFI Member
SEFI Member


Joined: 06 Apr 2015
Posts: 5

PostPosted: Thu May 11, 2017 4:44 am    Post subject: Reply with quote

Dear Biswa,

Your interpretation, "you do not need to take braking/tractive force in case of EQxx (as no live load is present) and need to take 20% of braking/tractive force in case of EQyy. " is not correct.


Clause 219.5.2  of IRC:6 depicts seismic force on live load need not to be taken when earthquake is in x-x direction. But (20%) live load is present in case of EQxx also.


So, braking force of 20% of Live load should be taken whether it may be EQxx or EQyy.




Greetings
Azarudeen.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Dams and Bridges All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy