LOAD COMBINATION-WIND LOAD 3

[Ramezsayed EIT]

I am using ASCE7-10 and ASCE7-16. and usually I use ASD Load combination

Wind Load is always multiplied by 0.6

Question:

I am multiplying the qz(velocity pressure) x 0.6 to get q asd

does that mean that I cannot multiply the wind load pressure by 0.6 while doing the load combination ? or will be multiplied twice ?

 

[phamENG]

What is q[sub]asd[/sub]? Don't think I've seen that one before. Can you provide a reference to the applicable section in 7-10?

The velocity pressure is rarely applied directly to the structure. There is typically another factor applied to it depending on the type and shape of structure and the type of wind loading you're considering.

 

[Ramezsayed EIT]

I am converting the Velocity pressure to ASD before adding the pressure coefficients which depends on the shape and size of the building as you mentioned. I am doing so since the Velocity mentioned in ASCE7-10 and ASCD7-16 is V ultimate .

Long story short, I convert the ultimate wind pressure to service wind pressure while doing the wind pressure calculations.

as an example we will take one of the code ASD Load combination equation 2.4.1.7 0.6D+0.6W

which Wind load will I use in the above equation ? working or ultimate ?

 

[DaveAtkins]

The 0.6W in ASCE load combinations is meant to be used with ultimate wind pressure. It is incorrect to calculate an ASD wind pressure prior to using the load combinations.

DaveAtkins

 

[Celt83]

ASCE 7-10 and 7-16 both are based on ultimate Wind pressure for use in the load combinations.


My Personal Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

Open Source Structural GitHub Group:

https://github.com/open-struct-engineer

 

[phamENG]

I agree with Dave and Celt. You shouldn't be applying a 0.6 "ASD" factor to the wind load. Calculate the wind load as the procedures in the code direct you to (which will give you an ultimate wind load), and then add it to the load combination (which will give you an ASD or LRFD/Strength load as desired). Don't mix and match combinations from one code and loads from another.