Air Spading near underground services

[David Humphries]

Interesting project David. Have you looked in the AA book - Tree roots in the built environment or the NJUG doc?

 

Hi David, someone's already mentioned NJUG v.4 (attached) but this is more focused on protection of tree roots.

Have you tried that very well known search engine and perhaps some keys words, e.g. "method statement for excavations for underground services"

...hint, hint.

 

Cheers..

Paul

PS Think BS5837 has a section as well but again focused on tree protection measures.

 

 

Hi both, thanks for the input.

 

Should have said yesterday that we (have copies) and had looked at both BS 5837; 2010 and the relevant NJUG doc but there's little (seemingly nothing) in them, specifically regarding hazards associated with using 'compressed air' in proximity to underground services. (if at all there is any?)

 

I met the National Grid contractors on site this morning to set up the monitoring system before they start using the mini digger, and although they have access to soil picks they seemed unaware of any guidance except relevant PPE whilst using them.

 

I haven't got a copy of the Tree Roots in the Built Environment at hand so I'll have a butchers at a colleagues at some point soon. If there's anything relevant I'll feed it back here.

 

Thanks again

 

 

Hmm not aware of such on this side of the pond, but I will dig a bit for that.

!

 

Cheers Guy, certainly interested if there is anything from the States

 

 

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[treeseer]

from our experience we've found that fine roots (and associated mycorrhiza) can be torn away from the parent root by the force of the compressed air and it can also dislodge stones (& other debris) which can cause impact damage to other roots. But generally, the air doesn't rupture through the root bark on mature roots.

 

With care, this level of damage can be limited, and the fine root hairs can regenerate over a short period of time. Particularly in loosely compacted soils.

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My experience as well, and with a more powerful tool.

 

Not exactly what you are looking for, but maybe close enough to be of interest--if you want to view the screen at 6 a.m. GMT!

 

Tree Protection During Construction: What You Don't Know Can Hurt You

 

Urban tree injury related to construction can degrade the performance of our urban trees, limiting their lifespan and even causing tree failure! Arborists, urban foresters and tree enthusiasts will learn about the latest research, and review proper practices, related to protecting trees during construction as they join guest speaker, Dr. Gary Johnson, University of Minnesota.

 

To attend, visit Join the Webinar | GoToWebinar and enter the Access code: 138-507-475

 

This noonhour broadcast is free and will offer the opportunity for arborists to earn 1.0 ISA CEU and 0.5 MCA credit.

 

For more information, contact:

Rick Harper

Department of Environmental Conservation

University of Massachusetts, Amherst

[email protected]

 

The Urban Forestry Today 2015 Noonhour Webcast Series is sponsored by the University of Massachusetts Department of Environmental Conservation, in cooperation with the Massachusetts Tree Wardens' & Foresters' Association, University of Massachusetts Extension, the USDA Forest Service and the Massachusetts Department of Conservation and Recreation.

[David Humphries]

My experience as well, and with a more powerful tool.

 

Not exactly what you are looking for, but maybe close enough to be of interest--if you want to view the screen at 6 a.m. GMT!

 

Tree Protection During Construction: What You Don't Know Can Hurt You

 

Urban tree injury related to construction can degrade the performance of our urban trees, limiting their lifespan and even causing tree failure! Arborists, urban foresters and tree enthusiasts will learn about the latest research, and review proper practices, related to protecting trees during construction as they join guest speaker, Dr. Gary Johnson, University of Minnesota.

 

To attend, visit Join the Webinar | GoToWebinar and enter the Access code: 138-507-475

 

This noonhour broadcast is free and will offer the opportunity for arborists to earn 1.0 ISA CEU and 0.5 MCA credit.

 

For more information, contact:

Rick Harper

Department of Environmental Conservation

University of Massachusetts, Amherst

[email protected]

 

The Urban Forestry Today 2015 Noonhour Webcast Series is sponsored by the University of Massachusetts Department of Environmental Conservation, in cooperation with the Massachusetts Tree Wardens' & Foresters' Association, University of Massachusetts Extension, the USDA Forest Service and the Massachusetts Department of Conservation and Recreation.

 

 

Looks interesting, thanks for the heads up.

 

 

 

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[JaySmith]

In the AA book tree roots in the built environment there is a very small section that talks about manual excavation using air spading but doesn't tell you much and certainly nothing that you wouldn't already know. For reference its section 8.6.2 page 275

 

There is also a small bit under section 4.6.4 page 108. They also recommend looking at Nathenson and Jarabak 2001 which gives some info but also a list of other resources at the bottom so maybe worth a look.

 

If you can't get hold of a copy of the book I'll scan the pages and email then to you if you like

[David Humphries]

2nd phase of the trench today, only one underground service to keep an eye on which was at the edge of the path.

 

Soil less compacted this end, so Air spade danced along uncovering more roots than the other end of the re-route.

 

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[David Humphries]

There you are knees deep in a trench happily airspading away, when you get not one but two calls from Arbtalk members

 

 

 

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[Paul Barton]

There you are knees deep in a trench happily airspading away, when you get not one but two calls from Arbtalk members

 

 

 

 

 

 

 

.

 

 

So that's why you sounded all muffled!

[David Humphries]

So that's why you sounded all muffled!

 

Ha, the muffled husky voice was me being excited talking about Mycorrhiza !

 

 

 

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[David Humphries]

Although we're monitoring the excavation (between other jobs), the mini digger is only as delicate as the hand that operates it.

 

The digger driver on this job has done a decent job of digging down and past the highlighted roots in the first trench, but the retained roots have suffered some level of collateral damage.

 

 

 

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[David Humphries]

..............

The digger driver on this job has done a decent job of digging down and past the highlighted roots in the first trench, but the retained roots have suffered some level of collateral damage.

 

To try an avoid the above we've covered the exposed roots in the second trench with coir fibre and plastic before the trench is lowered down to 1m

 

This should help reduce/deter further impact damage.

 

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