Wg in ShallowFoundationGen

[javidsharifi]

Dear all,
I am making use of the OpenSees command "ShallowFoundationGen". There is a point for which I could not have found a clue yet. In the subcommand used in the input text file "FootProp" what is the 6th term "Wg"? I am afraid no cue was provided in the document as far as came to my attention. I appreciate your kind guidance on this to me. I am looking forward to hearing from you.
Best regards,
B. JavidSharifi
SUTech

[fmk]

i have sent an email to the author asking him to respond.

[javidsharifi]

Thank u so much
I'll be looking forward then.
All the best

[arbabi]

hello
Wg is the "weight on the foundation from the structure", which come from weights above footing that you modeling it's foundation. it's weight unit is according it's primary units.
Good luck

[javidsharifi]

dear mr/ms arbabi,
thanks for your answer. yet here is an ambiguity. "weight on the foundation from the structure" means considering only dead load, or dead and a portion of live load?
best regards,
B. JavidSharifi
SUTech

[arbabi]

hello. your welcome.
in seismic analysis, generally applied load is 100% dead load and contribution of live load.
good luck.

[milosevicmaja]

Hello,

I am using this command for the first time. Is ShaollowFoundationGen command only used to model isolated shallow foundations or can it also be applied to a mat foundation, such as the one in the following paper:

IMPACT OF FOUNDATION MODELING ON THE ACCURACY OF RESPONSE
HISTORY ANALYSIS OF A TALL BUILDING
Farzad Naeim1, Salih Tileylioglu2, Arzhang Alimoradi1 and Jonathan P. Stewart2
1 John A. Martin & Associates, Inc., Los Angeles, California
2 Department of Civil & Environmental Engineering, University of California, Los Angeles

[javidsharifi]

Hi,
As far as i know, it is originally used for separate footings. but you may tie the responses using EqualDOF command in parallel base nodes as if horizontal ties are used between each two footings, or u can also use footCondition 2 or 4 to restrict the horizontal displacement to get it close to mat foundations.
Hope it helps
Behtash

[milosevicmaja]

Thanks for the advice. I will make an attempt at it.

[milosevicmaja]

Could we source PySimple2 and TzSimple2, which is developed/modified by Prishati Raychowdhury (UCSD), in Master.tcl file without using ShallowFoundationGen command?
Since we would like to build the foundation models ourself without using the ShalllowFoundationGen commnad. We only need to use PySimple2 and TzSimple2 elements in Master.tcl file.
If the answer is NO, please suggest how to do that?

Thanks !

[javidsharifi]

I believe it'll be OK, but pointless! The ShallowFoundationGen command does it exactly the same as you may need to. It also takes into account the zerolength elements wherever needed, as well as setting the distances of elements logically. Have you had a look at the subroutine created after this line is run in the master code?

[milosevicmaja]

Hello,
Our purpose is to model the mat foundation (not shallow foundation) with horizontal sliding by using PySimple2 and TzSimple2 elements in Master.tcl file.

We will not use ShallowFoundationGen command directly. Any thoughts?

[javidsharifi]

Couldn't you plant the UCD elements directly under base nodes and tie the horizontal movement of all base nodes to a totally fixed one? Then I suppose you may have to model the properties of the soil under each node specifically based on characteristics there (in case at hand) in order to account for possible asymmetric settlements. Reliability capabilities of OpenSees may come in handy too.