What I mean was,
1) ST = Type of structure which is 1 for RCC frame building, 2 for steel frame building and 3 for all other building. This facility is developed in the software to enable the program to understand and automatically calculate time period for moment resisting frame building without brick infill panel, considering clause 7.6.1 of IS 1893:2002(Part 1) based on userís input to ST using ,
Ta=0.075h0.75 for RCC frame building &
Ta=0.085h0.75 for Steel frame building.
Where h=height of the building in m.
Alternately if the user intends to consider time period for moment resisting frame building with brick infill panel, user needs to calculate time period using Ta=0.09h/Sqrt(d) of IS 1893:2002(Part 1) and feed this value in the program using Px and Pz parameter.
Px =Period in X direction (in seconds)
Pz =Period in Z direction (in seconds)
Px and Pz parameter are optional and is to be used as a substitute to ST.However if both ST and Px, Pz parameter are used together, program ignores ST parameters and proceeds with Px and Pz .
After obtaining the value of time period using ST or Px, Pz program calculates Sa/g using equation instead of figure 2 of IS 1893:2002(Part 1),
Sa/g (for rocky and hard soil sites) = 1+15T, 0 < T< 0.1
2.50 0.1 < T< 0.4
1.0/T 0.4 < T< 4
Sa/g (for medium soil sites) = 1+15T , 0 < T< 0.1
2.50 0.1 < T < 0.55
1.36/T 0.55 < T < 4
Sa/g (for soft soil sites) = 1+15T , 0 < T< 0.1
2.50 0.1 < T < 0.67
1.36/T 0.67 < T < 4
Emphirical Time period provided in IS 1893-2002-Part 1 to be used using Equivalent Static method are for Regular buildings only.
Alternately if a correct value of time period is to be derived and feed.the following can be used
a) Frequency from Modal analysis can be taken as per IS 1893-2005-Part 4
b) Frequency from Rayleigh method can be used as per New zealand code :NZS 1170
These frequency values can also be inputted in STAAD using PX and PZ parameter.
2) You have not considered seismic -X and -Z and hence I told u to consider those.Alternately STAAD has the facility to generate automatic load combination as per various international code.If u are using Indian code select IS code..and combination will be done by program.
|manoj_bisht wrote: |
I m not experienced abt staad and design.
Mr Adhikari , i have used your sample file ,can u guide me abt PX PZ and abt load combination ,is it OK.
Mr Rahul i have also rectified data as u guided me is it OK?