Seismic load on structures in pond

[gagnete]

Currently I am working on re-purposing a HDS pond to be used as a secondary containment pond. Approximately 40 ft into the pond will be a pump to drain the pond. The pump has to be accessed for routine maintenance so a catwalk will be built from the berm to the pump, which will also support the new piping. The question I have is how to design the rectangular structure that will contain the pump and act as a foundation/columns for the catwalk for seismic loads imposed by the water. From ASCE, it would appear that only sloshing loads need to be applied to the sides of the column. All of the references I have come across address tanks but leave out ponds and especially structures within a pond.

As of now I am calculating the sloshing load per API 650 and applying it to the surface of the wall per ACI 530.3 to check my overturning, sliding, structural integrity etc.

Any assistance on this issue would be greatly appreciated.

Thank you,
Eric

 

[TehMightyEngineer]

Not that there isn't a design standard for that (never seen one cover that myself) but remember that not everything has a code. Engineering judgement and all that.

Maine EIT, Civil/Structural.

 

[racookpe1978]

You have several things in your situation that actually help reduce the loading on your structure.

A "pond" is not a large lake or the free ocean, so wind-blown waves are going to be very low.
You can't get a "tidal wave" nor flooding as in a free stream or river bank or ice flowing downhill like a free river either.
With no flow, erosion is reduced over time, but corrosion remains.
The seismic event will shake (shock) the piles and structure sticking up because they are cantilever vertically from the bottom, but the earth under the pond and the water in the pond are going to react at slightly different rates, so the net forces act over a longer period of time - this will tend to reduce the total forces, not amplify them. (The water mass acts like a damper on the dirt, the dirt like a damper on the water mass.)

Treat the problem as if there were no water in the pond. That will be your worse case incident.

 

[JStephen]

Depending on the shape of the pond, a tank analysis may or may not be applicable to it.
The API-650 seismic provisions were based on a paper by Bob Wozniak. If I remember correctly, in the appendix of that paper, he also gave a formula to calculate the force due to the sloshing wave on interior columns in the tanks, and that may be of some help.
Note that the nomenclature of the loads has changed since then, so you'll have to correlate the older terms with newer.

 

[gagnete]

Thank you all, all of these are helpful and greatly appreciated.

-Eric