RamiHabchi93
Civil/Environmental
- Jan 22, 2017
- 26
Hi,
In ASCE 7-10,2.3.2 are given the basic combinations for strength design:
1. 1.4D
2. 1.2D + 1.6L + 0.5(Lr or S or R)
3. 1.2D + 1.6(Lr or S or R) + (L or 0.5W)
4. 1.2D + 1.0W + L + 0.5(Lr or S or R)
5. 1.2D + 1.0E + L + 0.2S
6. 0.9D + 1.0W
7. 0.9D + 1.0E
In equation 4 and 6 , W refers to wind,and in 5 and 7, E refer to the earthquack load.
My questions are:
1-is there any redundancy/overstrength factor to multiply wind loads(obtained by manual calculation or by software) with to obtain W? I mean to obtain the seismic load Eh we had to multiply QE(load obtained by seismic analysis) by a redundancy/overstrength factor.Is this a similar case? or W=wind loads obtained by applying wind pressure.
2-what are the directions of the wind that we should consider in the load combinations?I mean 2 orthogonal directions are sufficient?
3-For seismic loads ASCE 7-10,12.5 for each seismic design category gives a method of combining load effect obtained from applying seismic load in each direction.Is there a similar thing for wind? or the wind cases obtained for each direction are sufficient?
Thank u.
In ASCE 7-10,2.3.2 are given the basic combinations for strength design:
1. 1.4D
2. 1.2D + 1.6L + 0.5(Lr or S or R)
3. 1.2D + 1.6(Lr or S or R) + (L or 0.5W)
4. 1.2D + 1.0W + L + 0.5(Lr or S or R)
5. 1.2D + 1.0E + L + 0.2S
6. 0.9D + 1.0W
7. 0.9D + 1.0E
In equation 4 and 6 , W refers to wind,and in 5 and 7, E refer to the earthquack load.
My questions are:
1-is there any redundancy/overstrength factor to multiply wind loads(obtained by manual calculation or by software) with to obtain W? I mean to obtain the seismic load Eh we had to multiply QE(load obtained by seismic analysis) by a redundancy/overstrength factor.Is this a similar case? or W=wind loads obtained by applying wind pressure.
2-what are the directions of the wind that we should consider in the load combinations?I mean 2 orthogonal directions are sufficient?
3-For seismic loads ASCE 7-10,12.5 for each seismic design category gives a method of combining load effect obtained from applying seismic load in each direction.Is there a similar thing for wind? or the wind cases obtained for each direction are sufficient?
Thank u.