Lateral load on internal wall panels

[sybie99]

What is a reasonable area or line load to apply to internal wall panels in say a shopping mall (not as a result of wind load) In my case I have panels of 10m long x 3.5m high between shops in a mall building. depending on the lateral load I apply I may need to break the panels up with support columns. Obvioulsy the client does not want any conservatism in the design as it adds cost, only what is realistically needed.

Any comments?

 

[Parrapit]

Well the accurate way to do it would be to do the internal wall pressures, which depend on the amount of openings etc.

I had a similar thing in a mall, my wall was out of brick and much higher and longer and it was suppose to be a fire retaining wall.

I used a 1kn per square meter load which is a lot and I would not use that amount on partition walling or dry walling.

What material is your wall made of?

 

[sybie99]

Hi Parrapit, it is 230mm clay brick partitions walls. In South Africa our standard brick widths are 106, so with mortar gives 230 solid wall.

 

[Parrapit]

Nice I am also from SA Cape Town.
You can use the 1KN per m square should suffice. But in this case I would rather follow the Concrete Masonry manual.

It has tables of max spans and lengths for all types of walls internal external load bearing etc.

If you comply with those you don’t have to worry about a lateral (side) force. The wall's self weight will be enough.

 

[msquared48]

Don't know about your area, but the minimum lateral load for partition walls here is 5 psf, wind, pressure changes from opening and closing doors, errant children, etc., etc., etc.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

One kN/m² or 1 kPa is equivalent to 20.9 psf. I don't think anyone uses that in N. America although there are some situations where 5 psf is not enough. In a shopping mall, unless there are some very unusual conditions, it seems to me that 0.25 kPa (5.2 psf) should suffice.

BA

 

[sybie99]

Thanks BAretired, 1kPa does seem to much. Will use 0.25kPa which I think is reasonable.

 

[DST148]

@BARetired> I don't work in Canada any more. I have NBC 1995 part 4 Commentary which recommends pressure difference of the order of 0.5 kPa (about 10 psf). Did the codes change?
Also if I remember correctly the spacing of the lateral support (connectors) at the top of the partition walls was about 6'-8".

@sybie99 - Although 0.25 kPa (about 5 psf) may be adequate for design of the partition walls, the connections at the top of the wall (for lateral support) need to be designed for a much higher loading.

 

[BAretired]

DST148,

The current code is not specific about the magnitude of pressure for internal partitions. I have looked in the 1995 Commentary and cannot find any reference to 0.5kPa. What article are you reading?

I see nothing about the spacing of 6'-8". Where are you getting this information?

Why do the connections at the top of internal partitions need to be designed for a "much higher loading"?

BA

 

[DST148]

@BARetired> Ref User's Guide - NBC 1995 Structural Commentaries (Part 4)- Page 32, last 2 lines - Interior walls and partitions are not required to be designed for the maximum possible pressure difference . A design pressure difference of the order of 0.5 kPa (about 10 psf) may be appropriate.
I had worked in Ontario for a while. The connectors at the top of the exterior walls were designed for the actual wind / seismic loadings but subject to a maximum spacing of about 4'-0" unless the member at the top of the wall could span greater distances. However, for the interior partition walls the spacing of the connectors at the top of the wall was limited to about 6'- 8". I do not have the Ontario Building Code with me now and I am unable to cite the exact referenced section of the code.
Interior walls also need to be checked and detailed for seismic loadings. I was trying to bring the OPer's attention to the loads required for anchorage of masonry walls, which are much higher than the ones calculated solely based on 0.25kPa pressure (about 5 psf).

 

[BAretired]

@DST148,

Okay, thanks, I see it now.

Article 59 "Interior Walls and Partitions" of Commentary I of the User's Guide - NBC 2005 states in part "an unfactored pressure difference of at least 0.25kPa is suggested and a value of 0.5kPa or higher may be appropriate in cases where the exterior wind pressures are likely to be transmitted to the interior walls and partitions through large openings in the exterior envelope.

The Introduction to both the 1995 and 2005 commentaries, states in part:
"The Commentaries are provided as background information and, in some cases as suggested approaches to certain design questions, but not as mandatory requirements".

I would agree that there are situations where a higher pressure should be used. I think engineering judgment must be used to determine which pressure to use.

Seismic considerations are not much of a factor in Alberta but, yes, I agree that they must be considered where applicable.


BA

 

[valleyboy]

In the UK, some designers use 0.5 x external dynamic pressure. I think this is because older UK codes use internal pressure coefficients of either +0.2 or -0.3, the net pressure of which is 0.5. You could theoretically get this magnitude of loads across a partition in a building where perimeter walls are of unequal porosity.

Another consideration is will your wall be acting as restraint to crowd loads etc? In this event there are probably code requirements for horizontal loads?