Dear Arash Gholami,

I note the replies you have received on the design of your
anchorages. You have raised the more obvious areas which need
addressing.  Traditionally anchorage design has been undertaken
by specialist contractors - largely based on their intimate
knowledge of their own systems and methods of anchorage
manufacture and installation. As a consultant you might wish to
prescribe the working loads and any other constraints associated
with the construction. The detailed design and prescription of the
corrosion protection is usually left to the specialist designer - for
very good reason. You rely on their good engineering judgement
(and you can sue them!)

I agree with John McKinley that BS8081 is a very good place to
start.  It was written more as a text book than a code of practice.
This apparently was a very clear intention of Stuart Littlejohn at the
time. The new European Standard EN1537, whilst not based upon
BS8081, encapsulates many of the principles upon which it is
based.

EN1537 is very brief and only mentions matters which need to be
addressed.  It gives very little detailed guidance to someone who is
embarking on an anchorage design for the first time, say.  In the
appendix (Annex D), however, there is a very good alternative
design approach which you may wish to use. This addresses the
design on the basis of the steel failure criterion - an approach
commonly used in Europe.

You should be aware, however, that the corrosion protection criteria
are different from those articulated in BS8081. They have been
somewhat moderated to take into account other methods used in
mainland Europe - for example the French tube a manchette
system which uses a steel tube as a corrosion protection layer!
The principle which was followed in the drafting of this section was
that you should ensure that you have "one single continuous layer
of corrosion preventive material which does not degrade during the
lifetime of the anchor GUARANTEED INSITU!". The standard does
not quite say that, but that was the idea behind it. Mark Green is
right - it is very important to get correct corrosion protection. In this
respect I would recommend that you follow BS8081.

John McKinley raised the possibility of using the SBMA type
anchors. The single bore multiple anchor system promoted by
Tony Barley is one of the more significant contributions to
anchorage technology in recent times. (If you would like to have a
look at his webpage it is www.theanchorman.com.!) You will find all
you ever wanted to know about SBMAs on this website.

Good luck.

Caesar Merrifield
Convenor CEN/TC288/WG2 - EN1537.


Date sent:              Sat, 12 Oct 2002 23:25:18 -0700
Send reply to:          arash gholami <[log in to unmask]>
From:                   arash gholami <[log in to unmask]>
Subject:                Soil Anchoring
To:                     [log in to unmask]

>
> Dear engineers,
>
> We encounter the problem of soil anchoring (by strand) to control uplift pressure
>
> acting under bottom of an intake in iran.
>
>  If you had any experience or reference about:
>
> 1.optimum bond length
>
> 2. corossion
>
> 3.number and arrangment of strands(7,12,...)
>
> 4.grouting pressure
>
> 5.grout mixture
>
> 6.tension capacity calculation
>
> 7.safety factor
>
> ...
>
> or every useful information else please help us by your answer.
>
> Thank you in advance.
>
> Arash Gholami
>
>
>
>
>
> ---------------------------------
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_______________________________________
Dr Caesar M. Merrifield
Senior Lecturer
Manchester School of Engineering
University M13 9PL
Tel:- 0161-275-4340
Fax:- 0161-275-4361
alternative email address:-
<[log in to unmask]>