Terraced Retaining Wall suggestions

[obzpae]

Hi:

I have a backyard that needs terracing. The slope is approximatel 1 on 1. The dimensions are 60 feet wide and 30 feet high. There are water seeps in the hill and a drainage channel that runs down the middle. The water flows during the Spring and I would like to build walls that can retain the soil and allow the groundwater to be releived and provide a drain to accomodate the Spring rains. The soils are silty sands and there is bedrock present within the hill. Any suggestions on the best type of walls to be constructed for these parameters? Each wall would be 4 to 5 feet in height. Also can a type of planting be recommended for each terrace? The location is New York, near NYC.


Thanks,

John G.

 

[Gourile]

obzpae!
With the data you submitted, and with the height of walls you stated, I see no big deal of preparing drainage. You can design type of drainage used for small highway bridges, using granular naterial backfilled the wall and number of drains in the root of the wall to let water released. There might be just one point, the possibility of land slide on the slopes. As you are going to work on slopes which are sometimes become saturated of water, you should perform a slope stability and consider the possibilty of sliding. Note that the slope becomes more sensitive if you put more weights due to new construction on its active side,i.e. above centere of gravity of the sliding slope for a pecculiar sliding surface.