Design of Pile on Slope w/ Landslide

[TiffanyEIT]

so we're supporting a 250 ft pipe bridge via piles installed on a sloped terrain where there's landsliding but no liquefaction. I would like to know what are the checks I should do for a sound stable structure, especially on the landslide aspect. From a pile design aspect, anything I should take into account in STAAD Pro?

Thank you.

Tiffany.

 

[BridgeSmith]

I believe the soil pressure you'll need to design for down to the slide plane will be the passive pressure, which is usually 4 to 10 times the at rest pressure, depending on the soil. The "better" the soil, the worse it is when it moves and pushes against something. You'll want a good Geotechnical engineer in on this one.

 

[Lomarandil]

Even more so, depending on the spacing of your piles perpendicular to the slide direction, and the properties of the slide, you may develop a pretty significant "bridging" effect -- or thinking of it another way, the effective area of soil pushing against each pile may be larger than you think. (This was my grad school research).

You do need to take into account the lateral loading -- and for that, you want a good Geotech on your side for sure. If you can use more advice from the likes of us, I'd recommend asking in the slope stability forum instead.

----
The name is a long story -- just call me Lo.

 

[oldestguy]

Seems like double posting. That is frowned upon because most of us look at several "rooms". You might find the folks running the WEB site will delete any extra posts.

 

[bones206]

I just did a somewhat similar project. In my case, the client's biggest concern was that the structure could withstand the impact of a large (20 ft diameter) boulder. Your site may or may not have the risk of boulder impact from landslides occurring uphill from the structure, but that is something to consider. There are various ways you could protect the structure from boulders, like providing diversion structures or rockfall fences; adding redundant members, etc.

- Just a side thought on the double posting issue... it would be nice if you could cross-reference a single post under multiple "rooms", but still maintain a single thread. Just an idea. EDIT: Just to clarify, I meant that it would be nice if the website had an option to tag other relevant forums when you post something. For example, if you were doing analysis in RISA-3D and were getting weird results, you could post it in the Structural Engineering Other Topics forum, but tag the RISA-3D forum so it shows up in that forum's list as well. I think a lot of topics (such as the current one) would benefit from exposure to multiple forum audiences.

 

[BridgeSmith]

Some of us newbies here don't know how to straighten things out when we started a thread in one place and then, as happened here, were advised it would be better to post it elsewhere. All I know to do is add a link to other thread:

[URL unfurl="true"]https://www.eng-tips.com/viewthread.cfm?qid=439229[/url]

 

[oldestguy]

HotRod: It's easy to delete what you post. Just flag it as if you had a problem with it and say why. Management will remove it.

 

[BridgeSmith]

Thanks, OG. I'll keep remember that.