I am currently looking at a tower site that has an elevation that is over 500m above sea level.
For a number of the wind directions, the local topography also satisfies the following limit (and the tower is within the separation zone):
H/(2Lu) > 0.45
As such, the Mh hill shape multiplier should be calculated as per Cl. 4.4.2 (c) of AS1170.2 but when I compare the wind loading logs from the model to hand calcs it doesn't appear that this is the case.
Does MStower take into account the separation zone as seen in Figure 4.4 of 1170.2?
Thanks for your help,
Hi Michael, can you please confirm which version of AS 1170 you are using? MStower uses:
• AS 1170.2-2002
Hi Michael, what version of AS 1170.2 are you using? MStower uses:
Hi Michael, please see page 154 of the MStower manual. The software requests all the information necessary to calculate this value. Can you attach your MStower model and I will review the results?
After noticing the discrepancy between the anticipated wind speed and the wind speed calculated in the loading logs, a user input velocity profile block was developed as per pages 157-158 of the user manual.
Please find attached the MStower model created for the site in question.
Unfortunately, the velocity profile block is a workaround for sites around steep edges like this one but it takes the same profile for all directions. I have not found a workaround for this yet.
Do you know if there are any plans for the loading code to be updated?
Thanks for your help.
It appears that the hill-shape multiplier clause has not changed since between the 2002 and 2011: 1170.2 versions.
The snippet below is taken from the 2002 version of the code.
Is this check not completed?