Embedment of Railing's PostS in Concrete Slab 1

[Lina]

I am looking for a good reference or a tip to design the embedment of aluminum or steel guardrail's posts in concrete slab. The post as per local codes is subject to a lateral load of 200lb or it could be much higher if the post is a member of an exterior glaized railing where the system is subject to wind loads. I have seen other engineers using formulas that I am not familiar with and I could not locate any reference material on these formula.

a= 2 M^2 + 3L.M /3M + 6L


P2= a^2 x P / [M(2a-M)]

M is the embedment length of the post in the concrete slab
L is the height of the guardrail post
P is the lateral load applied on the top of the post described abve
P2 is the resisting force to P below concrete slab

 

[kogo]

check-out '97 UBC Sec1806.8

 

[Lina]

Kogo

Can you briefly explain this section. I do not have this code but I am willing to purchace if this section is related to my question.

 

[Ginger]

An approach to use is given in the Steel Designer's Manual 4th Edition published by The Steel Construction Institute. Look in the index for pocketed crane foundations. Although your post is not steel the same theory should apply. Andy Machon

 

[Lina]

Ginger
You had already mentioned this manual. I sill cannot find it. What do you mean by the Steel Construction Institute? I couldn't find this assiciation. Do you meaan AISC? Can you give me contact information.
Thanks.

 

[kogo]

Lina,

ubc '97 states:

The following two formulae may be used to determine depth of ebbedment.....

d=A/2(1+(1+4.36h/A)**1/2)

&

d*2=4.25Ph/$b

where: A=2.34P/^b
b=diameter or diagonal of post in feet (m)
d=depth of embedment
h=height of load
P=applied load
^=allowable lateral soil-bearing pressure as
set forth in table 18-I-A based on a depth of
1/3 the depth of embedment
$=allowable lateral soil-bearing pressure as
set forth in table 18-I-A based on a depth
equal to the depth of embedment

The first formula is for the non-constrained condition
(post in unpaved soil)
and second formula is, I believe, your case....where the surface is paved.


In the first formula you have to play around with "d" and "A" until you get a "d" (or an "A" but in most cases it will be "d&quot that you can live with.

 

"Ginger's" reference is to a UK publication.
Steel Construction Institute is a British organisation.
See

http://www.steel-sci.org

and follow the links Courses & Publications...Publications...Index by Subject Category...General Publications on Structural Steelwork

Other UK/European steelwork stuff is in the Corus website

http://www.corusconstruction.co.uk

Corus Group plc was formed in October 1999 by the merger of British Steel and Koninklijke Hoogovens of the Netherlands. The Corus site has various on-line design resources and provides links through their 'Organisations' page to SCI (Steel Construction Institute) and BCSA (British Constructional Steelwork Association), so tag this site if you want to keep a bookmark to UK steel practice.
regards Tom