Effect of surface surcharge on slope stability?? 5

[JasonG]

I need to evaluate the maximum amount of fill I can place near a 1:1 slope. I also need to evaluate various distances of the fill from the top of the slope. (for example: place 5 feet of fill 10 feet back from the top of the slope)

How should I include the surcharge forces from the fill in the slope stability analysis? I plan on using the Simplified Bishop Method (if that is an approriate method for this case).

Thank you.

 

[cdh61]

JasonG

Waht is the existing fill, and what will the new fill be?

regards

 

[JasonG]

The existing fill is sand and gravel. The new fill will probably be similar.

 

[TerraBoy]

I think you are to praised for building a spreadsheet. Programs are only as smart as the people that use them and building your own program is a time consuming, but highly beneficial way of understanding the method of slices.

One useful resource with the spreadsheet is "Slope Reliability Analysis Using Generalized Method of Slices." It is in the Journal of Geotech & Geoenviron. Engineering Vol 124, No 4 - April, 1998. It shows how to set up Morgenstern and Price and Spencer methods (which satisfy all conditions of equilibrium) and takes advantage of Excel's solver to do some searching for you.

 

[JasonG]

TerraBoy,

Thanks for the kudos. It was a daunting task, but I was able to develop an excel spreadsheet that completely automates the simplified bishop method. The output is practically identical to that of commercial software.

 

[cvg]

a disadvantage to writing your own software is getting the agencies / regulators to accept it. Maybe the only way for them to approve your work is for them to run another program and try to duplicate your results.

 

[BigH]

Has it come to that? What difference? Do they not accept hand versions of Bishops analyses (aka vide Terzaghi and Peck's book) like we used to do before personal computers?? Why do they want to "know" the programme? Just a bunch of questions but . . .

 

[JasonG]

It's been my experiance that regulators must accept the calculation method (i.e. bishop), not the method used to perform the calculations (i.e. software). They may not accept the results from a software package that uses it's own method.

 

[Focht3]

Hmmm,

I always use the software to "zoom in" on the critical circle, then confirm the answer with hand calculations. It's quite efficient from a time use standpoint -



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"