Achor without been pulled out 5

[JietChua]

thread256-135127

hi i'm still a student and now i intern in a company
they want me to calculate for the bridge anchor which the anchor can withstand 100kN without been pulled out and for the passive & active pressure
i'm still a new one and not really study about this bridge, so if can please say it in more general way or provide me some link
appreciate for everything

 

[Ron]

Your category notes that you are an electrical engineer. This is a task for a structural engineer with geotechnical input. You have not given enough information for us to guide you further, other than to get a structural engineer involved with this.

 

[L0k]

Hi Jiet, I think you know the diameter should be installed, inclination of the anchor and the type of rock. The above data will lead you to find the length of your anchor. It will be helpful if you have the bore log of the rock including RQD and joint thickness.

 

[JietChua]

thanks for your comment Ron
and yeah i'm actually study in mechatronic, but as i intern in that company i just can follow what they told me to do so.
and my supervisor hear after what i'm explain for him about the bridge and problem i facing during calculate for the bridge, he just want me to find the anchor depth and the degree in the fine grained soil that is clay that can withstand 100kN of force without been pull out
i find some information but i just don't really understand about it especially the active & passive force

 

[JietChua]

thanks for the comment L0k
i'm really a fresh one in here, i don't even clear about most of the formula use in bridge
my supervisor after heard what i explain then he asking how to calculate the force that ensure anchor been pulled out and while i explain the need of diameter, size and etc then he stopped me and just want me to focus on anchor and calculate the depth the degree of the anchor which in low-grade soil without rock in the soil and can without up to 100kN without been pulled out
and the formula and diagram i found on internet make me confuse

 

[bridgebuster]

perhaps the attached will be of some help to you

 

[JietChua]

Thanks for the comment bridgebuster
Yeah, that will help me understand more for it
I'll go through in details after I done what I told to do
Thank you!

 

[bridgebuster]

you're welcome, good luck.

 

[oldestguy]

Another reference or two

 

[oldestguy]

The second one

 

[oldestguy]

A final note.

Bridges are designed by or the design is verified by a licensed engineer in most places. In your case emphasize that this also is a requirement due to the design being a structure that carries people or c an injure someone. Make sure a qualified person verifies your design is safe. Even well experienced engineers can miss something.

 

[JietChua]

thanks for the comment oldestguy
thanks for the short note!
i really got no idea when reading from internet and i can't imagine anything about the bridge force
thank you!

 

[JietChua]

hi oldestguy
can you give me the full link or about the book you refer me?
i really need the book with some figure for more understanding

 

[oldestguy]

Here is a Google search title that I used. It brigs up several places where it can be obtained free. These publications came from the US Navy some years back.

NAVFAC DM 7.2

In your case, with the questions you have, I think the "boss" should know that this is not something that you should be asked to do. The least you need is a course in soil mechanics and preferably some structural engineering courses. Isn't there someone there to guide you on this? It sounds like even they may not know all that is needed to know.

With what I sent before as attachments any one with some degree of training in these subjects should be able to complete the task. For instance, you also need properties of the soil conditions at the site which can vary considerably depending on ground water conditions.

 

[oldestguy]

In DM-2 look on pages 170 to 172

 

[JietChua]

thanks for the sharing oldestguy!
for real there is no one here know about it.
there is no one here have study the relate courses, my manager just told me to make an example of it and i really have no idea where to start, it really hard to understand when come to find and summaries the other courses that haven't study or having any hint about it. it just like speechless when he call me to find
anyways, thanks for the sharing!
have a good day!

 

[JietChua]

hi oldestguy
can you provide me some useful link or note for anchor?
the best is having some showing of calculation
thanks

 

[oldestguy]

You might do a search via Google. I did one for "Anchor block design". A lot of this is for pipe lines.

Many things came up, but on the second or third page something that may help. Note the lower strength once the soil was saturated.

http://faculty.kfupm.edu.sa/CE/nshayea/Papers/C1.pdf

 

[JietChua]

hi oldestguy
okok, thanks for the help
the link you gave i just couldn't go in there
i wanna ask above the angle of anchor cable should be what degree is the best?
or any link about this or some example?

 

[oldestguy]

We don't do design here. However, assuming this deals with a suspension bridge, you will have to do a lot more than design the block. As you raise and lower the "tower", the pull from the bridge varies. If you only vary the location of the anchor, you still vary the details at the tower. Other than that, the lower you can make the anchor angle to horizontal, the better the anchor holds, assuming it's dimensions don't change. Raise and lower the tower and the pull changes. Interesting variations that can be entered into a formula for finding dimensions of anchor for various angles.