header.askHiltiTitle

How to calculate alpha to convert LRFD capacities to ASD capacities for HILTI KB-TZs. ESR 1917 mentions alpha is a weighted average of load factors for controlling load combination (Pg 4 of 14). How do I find these weights?

question.postedBy Karthika Rameshabout 6 years ago
How to calculate alpha to convert LRFD capacities to ASD capacities for HILTI KB-TZs. ESR 1917 mentions alpha is a weighted average of load factors for controlling load combination (Pg 4 of 14). How do I find these weights?

On pg 13 of 14 the weights are taken as 30% for Dead and 70% for live. Please explain how you arrived at these weights

ASD,HILTI KB TZ

1 question.answer.reply
question.postedBy Bryan Johnsonabout 6 years ago
question.answer.verification.hiltiVerified

Karthika,

As you have mentioned, the alpha conversion factor will be based on the load combination factor and the weighted contribution of the load types based on the individual project. The example that you are seeing in Table 7 on page 13 / 16, is for illustrative purposes only, to show how to calculate the alpha conversion factor. Ultimately, it will be up to the engineer of record to provide the weighted load average, and confirm the use of the correct load combination equation to determine alpha. For your reference, attached is a copy of the ICC-ES Technical Letter describing this subject in more depth.

Let us know if you have any additional questions.

Regards,

Bryan


1 question.answer.commentOnReply
question.postedBy Karthika Rameshabout 6 years ago
Thanks Bryan the attached doc. was very helpful!