Steel-Reinforced Elastomeric Bearings Stiffnesses and Damping 3

[Uzil]

Hi!

I was tasked to identify the spring constant of the designed bearing pads in accordance with AASHTO LRFD 2012 Specification. My problem is, I cannot find any writing within AASHTO that demonstrate the calculation of these constants (stiffnesses). I was able to read the provision of Australian Code and they presented a direct formulation for these constants based from the geometry and property of the bearing pad, however, I am not sure if I can incorporate these provisions with the AASHTO designed bearing pad.

Also, I have read from another thread that someone used the "Design Guidance- Geotechnical Earthquake Engineering for Highways, Volume I - Design Principles" publication and used the equation for rectangular footing stiffnesses. The formula given can be easily understood, however, some parameters are using the characteristic of the soil which differs from the case of bearing pads.

Can anyone suggest an acceptable method to determine these constants as well as to know the damping capacity of bearing pads?

Thanks a lot.

 

[crossframe]

Seismic Design of Bridges, Publication Nos. FHWA-SA-97-006 through FHWA-SA-97-012, is a seven-volume set of design examples of different bridge types. Each example is incomplete, in that they are intended to demonstrate different aspects of the full design. Things omitted in one example are often covered more in-depth in another example. In the past I've used Example No. 2 (FHWA-SA-97-007) to determine spring constants of steel-reinforced elastomeric bearings for use an a computer model. The publication is dated (I think it's based on the AASHTO Standard Specifications), but you may find some useful information if you can find those examples. Most of the time, the bearings don't know whether their stiffness is supposed to be LRFD, LFD, or ASD.

 

[bridgebuster]

Let me know if you can't find the examples. I have a copy of them.

 

[Uzil]

Thanks crossframe for the information. I'm sure I will be able to learn alot from these references.

However, I am having difficulty finding these publications. It would be very helpful bridgebuster if I can have a copy of them.

Thanks in advance.

 

[bridgebuster]

Uzil - Here is example No. 2

 

[bridgebuster]

Example 3

 

[bridgebuster]

Example 4.

It's a hectic day at work. I'll try to upload the other 4 examples over the holiday.

 

[Uzil]

Thanks you so much for these bridgebuster. Happy thanksgiving day!

 

[bridgebuster]

You're welcome Uzil. Happy Thanksgiving to you.

 

[bridgebuster]

Example 5

 

[bridgebuster]

Example 6

 

[bridgebuster]

Example 7

 

[bridgebuster]

Last but not least, Example 1.

 

[Uzil]

Nice. I have downloaded all the files. Thanks bridgebuster!

 

[bridgebuster]

you're welcome