We face an issue with a diagonal anchor layout for HST3 for seismic design calculations. The message we get is: The selected anchor layout and anchor plate shape combination is not allowed with seismic design.
For static and quasi-static design the layout works fine.
Can anyone help us to understand why it doesn't work for the seismic design, thanks.
Dear Mr. Halama,
thank you for your contact from today. In this case and with this dowel arrangement, the SOFA method is required.
Here you may find some information about the SOFA Method (German and English):
https://ask.hilti.ch/article/machen-sie-das-beste-aus-ihrer-konstruktion-solution-for-fasteners-sofa/wh113e
https://ask.hilti.co.uk/article/what-do-we-mean-by-sofa/wliw8x
Unfortunately the SOFA Method cannot be combined with a seismic calculation. In that case, there could be two approaches to the problem:
- Try to change the dowel arrangement into an approved arragement from EN1992-4. In this example the problem could also be splitted in smaller arrangements, so that SOFA is not required
- Perform a static calculation and with engineering judgement integrate the reduction factors to include the seismic influence in the calculation. You can see the reduction factors in the exported report.
If you want further support please contact us under ch-technik@hilti.com with more details to the problem. Please note that company holidays apply until January 3rd. Thus your question might be answered from the new year.
Thank you for your understanding. We wish you a great time during Christmas season and a happy new year!
Best Regards
Your Hilti Engineers
In the National Annex Swiss Code (SN) EN 1992-1-1/NA:2014, which is an integral part of SN EN 1992-1-1 and therefore decisive for the application of EN 1992 in Switzerland, NDPs to be applied in this country are defined. Annex A no reduction of the partial safety factors is permitted:
s,red = s = 1.15 and c,red = c = 1.50.
For the reduced partial safety factors country-specific values (NDP) are provided. A reduction was deliberately omitted, in particular because the "increased quality requirements" specified in EN 1992-1-1 as a prerequisite for a reduction are comparable with the the usual requirements of SIA 262 (in some cases even less restrictive). A reduction would therefore have led to an undesirable reduction in safety the level of safety that is currently accepted in Switzerland. Although RECOMMENDATION OF THE SIA 262 STANDARDISATION COMMISSION Reduction of partial safety factors not permissible.