Foundation for Tidal High groundwater Table

[kxa]

What is the best choice of foundation for a residential house located close (50’) to a canal with a 4 foot tide fluctuation? Frost line is at 3 feet and the groundwater at 2 feet below the grade.

 

[SlideRuleEra]

The best is probably piling. Individual piers on spread footings, below the frost line and water table, should work well also - probably more cost effective than piling.

http://www.SlideRuleEra.net

 

[fndn]

You'll need to check for the maximum scour depth - Hydrogeologist should be employed. Also need to have very deep borings to check for any compressible soils. Based on the investigation data you may have several options from deep foundations to building a cutoff wall and then raising the building pad for conventional footings/slab on ground design.

Even Mat foundation is feasible once uplift and quick sand conditions are accounted for in the design.

 

[VAD]

In addition to responses provided you may wish to look at the canal itself. Not sure if it is an earthen type. Depth of canal, evidence of any bank slumping, overall stability are some factors to take in consideration as well. How is ground water related to level of water in Canal.