Smart questions
Smart answers
Smart people
Join Eng-Tips Forums
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

Join Eng-Tips
*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.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

igdelimb (Structural) (OP)
2 Feb 10 18:30
I am trying to find another reference to the crane impact loads. ASCE 7-05 Section 4.10 lists the following impact ratios for different type of cranes which is similar to AISC ASD 9th Edition Specifications for Structural Steel Buildings 1989.

ASCE 7-05 4.10.2 Vertical Impact Force. The maximum wheel loads of the crane shall be increased by the percentages shown in the following text to determine the induced vertical impact or vibration force:
a. Monorail cranes (powered) - 25%
b. Cab-operated or remotely operated bridge cranes (powered) - 25%
c. Pendant-operated bridge cranes (powered) - 10%
d. Bridge cranes or monorail cranes with hand-geared bridge, trolley, and hoist - 0%


Per commentary on the AISC ASD 9th Edition Specifications for Structural Steel Buildings 1989, these percentages are based on the Association of Iron and Steel Engineers publications (AISE 1979), so these percentages seems to be specific for bridge or overhead cranes supported by steel structures. I was wondering are there any other references for gantry cranes and their impact loads which are supported by concrete structures. Does anyone know ISO 12480 may have some guidance on the impact loads?

Thanks
 
msquared48 (Structural)
2 Feb 10 20:48
Why would the type of structure supporting it have any bearing on the required impact load to the crane components?

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

ishvaaag (Structural)
3 Feb 10 10:27
Really not a material intrinsic issue but concrete PC or RC runways may show less dynamic effects upon some bigger stiffness present and so on. These things may be compounded to vary the impacrt factors.
weab (Structural)
3 Feb 10 22:07
igdelimb,

Try CMAA Spec 74.  This is the Crane Manufacturers Association of America.  I think this is the best reference on the subject.  The impact factor appears to be in the Hoist Load Factor (HLF).  It states:

HLF = 0.15 < 0.005 x h oist speed in fpm < 0.5

where live load is factored by (1+ HLF).  However, it includes several different factors so HLF cannot be used alone.

 
BENDOG (Structural)
4 Feb 10 6:50
Also try AISC Design Guide #7 on Industrial Buildings.

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!

Back To Forum

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close