AS4970 Draft| Australian Development Tree Protection

Sean Freeman

12 X DBH is the RADIUS of the Tree Protection Zone.

So a 400mm DBH Euc gets a TPZ of 4.8m radius

Eric Frei

From the center of the trunk. So if you are measuring to the trunk always remember to adjust if need be.

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Sean Freeman

Attached Thumbnails

 

MTS247

Sorry thats what i ment honest

SRZ is calculated as diameter?

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"Just cause i don't use it, don't make it wrong!"

Sean Freeman

No as radius, my diagram is showing DBH and TPZ not SRZ

MTS247

Ok both radius, i swear i saw one was diameter and one was radius.
I'll post the bit that confused me tomorrow.
And we can have a laugh

Thanks

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"Just cause i don't use it, don't make it wrong!"

MTS247

not sure what i was thinking you were right, of course

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"Just cause i don't use it, don't make it wrong!"

Eric Frei

I made some lines on this graph to assist but have discovered it is way wrong.

Refer to this thread. I also have built an online calculator for this equation.

TPZ| SRZ| AS4970-2009 Online Calculator

Attached Thumbnails

 

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Eric Frei

Please note:- An amendment has been issued 26 March 2010 for the graph.

It is available as a free download (you have to be logged in to get it though) here.

AS 4970-2009/Amdt 1-2010 Protection of trees on development sites

It's good to see they ruled it up similar to the way I ruled it up, also it appears to be accurate now. Better still, use the online calculator.

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