parking garage

[fagg1]

have someone some experience with OPEN car storehouse.
OPEN - means that I must take care on temperature influence.
My object is 180x120m big, and have 4 floors.
It is concrete structures, and the space between column is 10x7.25m.
Here is the question for you (to help me):
- live load for car storehouse (or parking garage) is ?? (looking for minimal)
- Do you consider the temperatute loading ??
- is 60x60m to big for one field

thanks bart

 

[visitor]

The live load can be 2.5 KN/Sq.M which is similar for carparking structures.

 

[kieran1]

A live load of 2.5 KN/m2 should be allowed for. As for the temperture affects the carpark structure is usually more flexable than other structures. I would provide expansion joints at the 60x60m grids as you have suggested, usually in the form of a double line of structure with enough space for expansion between them. Expansion can be worked out for the materials co-efficient of linear expansion and the temperture range for the area in which the structure is situated
but don't for get about contraction also. Joints should be flexible for expansion and contraction Kieran
BEng(hons),CEng, M.I.Struct.E, M.I.E.I.

 

[ishvaaag]

NBE AE 88 Table 3.1 asks more, 400 kgf/m2 or about 4 kN/m^2, service level.

 

[Ingenuity]

fagg1,
Is this proposed structure going to be post-tensioned (P-T) concrete? If so you need to carefully consider restraint from stiff columns or walls, most especially at the perimeter.

HTH

 

[rapt]

Live loading varies between countries. It should be defined in your loading code. USA is 2.5KN/m2, Australia is 3KN/m2. Other countries will be different. Can light trucks enter the building. If so loading may be 5KN/m2. If garbage or fire trucks can enter then 12 to 15KN/m2 in those areas.

Temperature differential should definitely be considered for the roof. Temperature shortening as well as shrinkage shortening should be considered in the design of expansion joints and of columns and connections if long pours are done or stiff columns connected.

60m by 60m is propbably too much to pour in one pour, especially on a project where there are going to be multiple pours on each level. The normal limit woulod be about 1000 to 1200m2 per pour. Also, if post-tensioned, 60m is far to far to stress from one end, as would be required for connecting slabs. 60m lengths of slab will also cause severe cracking in columns.

 

[flamby]

One point that you should never neglect is the car loads on upper floors should be taken as point loads and not as UDLs. Point loads on wheels will result in substantially increased moments that you have to cater for.

 

[sven]

I disagree with flame's comment. The weight of a car is far less than even 2.5kPa. By the time you divide it over 4 wheels and consider how far away the next car is... the Code design UDL will govern for strength.

I agree with rapt, you should design to your local Code requirements, or to a recognized foreign code.

 

[LPPE]

Check both cases of UDL or point load. Design for the worst case.

 

[ishvaaag]

It is a fact that some codes allow to design for only an uniform load (for example Spain's NBE-AE 88). However when trucks load the floor I think worth the effort -and better- to check as well the structure for tire/truck loads. This may be also the case for low weight vehicles if too thin parts are used between joists or so.