How do I calculate thickness needed for a retaining wall?

[joe17857]

I need to calculate the thickness needed for a retaining wall for a pond. The information I have is as follows:

Depth of pond, area of pond, shear strength of retaining material, unconfined compressive strength of retaining material, length of retaining wall (will only be on one side of pond). There will be no slope on the retaining wall.

How do I calculate the thickness of the retaining wall with a 1.7 factor of safety?

 

[Blank_Stare]

In my experiences in the trades, talking to the local inspector who will ultimately review the plans, and inspect the work is the most direct course of action.

Stop in his office, when he has office hours, and tell him you are there to make sure you satisfy HIS requirements, and he will usually take a liking to you, and your approach. After all, he doesn't want to visit your site more than he has to (they hate re-inspections), and he doesn't want to have an argument with you later, to get you to change your plan/prints to conform to his requirements - talking to him first, puts him in the driver's seat. It also greases the wheels of the inspection process, since he will already be intimately familiar with your project, before he arrives to inspect, or for that matter, before he reviews your construction plans. It can also save you a lot of time re-doing your work, whether it be on paper, or in the field, since you will know what he expects, before you even start drawing the plans.

Even if the location precludes an inspection requirement, the inspector can still be an invaluable resource. You pay his salary with your taxes - why not put him to work for you? If he mentions that a permit/inspection process is not required, just let him know that you have safety concerns, and you wanted to consult an expert authority on the project. More likely than not, he'll spend at least SOME time with you.

If you are looking for a purely academic answer, I'll leave that to others who are more familiar with the math involved.

 

[Filip Larsen]

For a tool-based approach to model and simulate your problem, or to cross check your own calculations, you might want to consider using a tool like Optum G2 which I know is used for providing upper and lower bound limit analysis (collapse) for real-world geotechnical problems. The tool is not free, but has a free trial. For sake of complete disclosure, I recently started as a software engineer at the company making this simulation tool and should be able offer help with the tool itself but I will have to refrain from offering any advice on the actual geotechnical modelling of your problem as that is well outside my area of professional expertise.