Prediction of surcharge (lateral pressure) from existing buildings and/or traffic. 2

[ayithi]

All,
Can any body suggest me some good references or info about "how to predict surcharge ( for lateral pressure) from existing buildings and/or local traffic" that can be used for tie-back shoring wall design?
No of stories of the building and street location are known.

Thanks a bunch in advance.

 

[DaveAtkins]

250 psf is commonly used to account for vehicle traffic.

For the building, I would calculate the dead load plus a reasonable assumption for live load (since you have a multi-story building), and divide by the building footprint to determine a surcharge. But if you have isolated footings very close to the wall, you should use the calculated bearing pressure under the footings.

DaveAtkins

 

[ayithi]

DaveAtkins,

Thanks for the info.
Unfortunately, I don't have any information about the dead & live loads for the building. All I know is no. of stories.
Can you suggest some references or info to approximate these loads. I don't want to be too conservative and its a temporary shoring, may be for 6 months max.

 

[PEinc]

Visit the site. Walk through the building measuring the height, wall thickness, column spacings, and determine the type of foundation, if possible. You have to figure out the DL and LL of the building. This is done all the time for underpinning jobs. For most projects, there are not plans available for the adjacent, existing buildings. IMHO, conventional sheeting walls are flexible systems and are not usually appropriate for supporting a building. Consider whether or not the building needs to be underpinned.

http://www.PeirceEngineering.com

 

[Retrograde]

I would generally assume 10kPa per floor working load for a residential building. Probably a bit higher load for a commercial or retail building.

 

[PEinc]

I would not "assume" the DL and LL for a multi-story wall that might be supported by a flexible sheeting wall.

http://www.PeirceEngineering.com

 

[bdbd]

NAVFAC gives 10 kPa to 20 kPa for a floor. Based on my experience unfactored G+Q stays always between this two range if you add raft load seperately.

My experience: For buildings over 10 floors, use 15-20 kPa per floor, if you do not know the raft thickness, assume a thickness and multiply it with 24 kN/m3. For below 10 floors, use 10-15kPa + raft thickness*24.