×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Conveyor Loads

Conveyor Loads

Conveyor Loads

(OP)
I am calculating foundation loads for several conveyors and am curious whether I should include seismic forces.  These are for an area that used to be UBC zone 2.  I have been told that no one else does this.  Is there a special design spec for conveyors?

Thanks,
-Mike

RE: Conveyor Loads

Typically for bulk material handling conveyors we don't design for seismic loads unless we are in zone 3 or higher.  Sometimes in Zone 2A.  It usually depends on the customer and the situation.  95% of the time it will not control anyway until you get to the higher zones.  Even in the higher zones the customer only wants the structures to meet seismic and the conveyors not.  The justification is that the conveyors are "low risk" to human life and are highly redundant so when designed for wind they will survive most shakes.  Also consider the return interval for quake design and the life expectancy of your structure.  A conveyor more than 25 years old in a quarry, although not unheard of, is generally few and far between.

If you do include seismic we usually include dead load and the operational TPH material live load.  We do not use the maximum "surcharge" material live load for design.  We do put on the drawings that conveyor designs do not condsider seismic forces and at the discretion of the owner can be included.

RE: Conveyor Loads

(OP)
aggman,

Thanks for the help, you make several good points.  I see now after a few more hours of programming that my seismic forces are about 25% to 30% of the wind forces so the break even point would be about zone 3 roughly.  I do have a conveyor indoors so I'll probably use seismic there for the purpose of checking for minimum stability, but due to the use of standard parts should be better than needed.  Using the surcharge LL is probably overly conservative as you indicate.

Putting a note on the drawing about seismic design is a nice touch and seems to be the appropriate thing to do.  I would like to do that here but probably won't be able to.

Thanks again, it's nice to get a viewpoint from someone else in the business.

-Mike

RE: Conveyor Loads

There are some applications where the end use of the conveyor dictates looking at the seismic loading. Most coal fired power plants are expected to not only survive a design earthquake, but also to continue to produce electricity immediately afterwards. If the coal handling system went down, the inability to deliver fuel would bring power generation to a screeching halt within hours.

www.SlideRuleEra.net

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources