wall loadings in etabs

[monchie]

Hello,

I am using Robot Millenium software for a couple of years now and I'm just wondering if ETABS can do the same capabilities in putting various load scenarios on a wall(see attached file).

Fig. 1 - Normal to the wall point loads(how do you create nodes in ETABS to put the nodal loads?}

Fig. 2 - Increasing pressure loads normal to the wall.

Fig. 3 - Increasing pressure loads on part of the wall

Fig. 4 - Normal to the wall point loads with moment.

Any help will be greatly appreciated.

Regards.

 

[johnbridge231]

ETABS has unfortunately some limitations regarding loads on areas (on the other hand SAP can apparently do more), so none of your 4 cases is supported. Only uniform and thermal loads can be applied to areas.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[amadeus]

Excuse me, but I don't think so. If you manually mesh the wall, then you can select a corner point and apply any type of point load on it, moment or forces. Just be careful about the direction on which the point load is applied for the model to be accurate. On the other hand, once the area is manually manually meshed, you can assign independent normal distributed loads an each of the resulting elements. On higher elements, the loads will be smaller if you are modeling soil pressures. Let's try not to offer explanations if we are not sure about them.

 

[johnbridge231]

You are talking about point loads. Point loads can be apparently assigned to points.
Point loads on areas cannot be assigned directly. This is obvious.

"Let's try not to offer explanations if we are not sure about them." -> very smart.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[amadeus]

I think if monchie is asking for help, telling him ETABS does not do something, when in fact it can do it, will not help him very much. Helping each other is the whole point of this site, isn't it?

 

[johnbridge231]

Wrong! ETABS can't do that. Have a look at my previous post! Maybe you should drop a quick look at the eser manual.

Regards.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[johnbridge231]

* User Manual I mean...

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[stressed]

1. Normal to the wall point loads in ETABS - applied exactly as Amadeus described. Mesh the wall, select the joint(s) and assign joint load normal to the wall. Mesh point on the wall can be precisely specified by using reference planes and reference lines to mesh by gridlines.

2. Increasing pressure loads normal to the wall - Since ETABS lacks the joint pattern feature like SAP2000, this can be accomplished by meshing the wall and assigning different pressure loads at different heights on the meshed wall panels, which is a bit less convenient than using the joint pattern feature, although it can be done. There is a joint pattern example described in the A to Z example problems if you look at example H. I am guessing that the new version of ETABS will offer this feature since it's been part of SAP2000 for quite a while.

3. Increasing pressure loads on part of the wall - same as described in #2. You would mesh the wall and assign different pressures wherever you want. Those pressure loads by the way, do not have to be normal to the wall, they can be in any direction along the wall's local axis or global axes.

4. Normal to the wall point loads with moment - same mesh procedure as described in #1. Select the joint(s) and assign forces and moments.

In Robot or ETABS, the results will depend on the mesh. Robot appears to offer some automatic meshing for walls. How that mesh is applied will make a difference.

 

[johnbridge231]

Dear User amadeus-stressed,

I think that you have heard of the difference between a point and a plane.
These should be clear to you. Then we can have a nice and constructive discussion about your issue. If you need any help kindly let me know.

Regards,

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[stressed]

johnbridge, everyone is clear about the difference between a point and a plane. What are you trying to say?

Your statement upthread that "none of your 4 cases is supported" by SAP2000 is demonstrably incorrect.

If I missed something, please tell me what exactly, and be specific without smug commentary.

 

[johnbridge231]

I did not reffer to SAP2000. stressed, never mind, forget it.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html