Terraced retaining wall suggestions

[obzpae]

Hi:

I have a backyard that needs terracing. The slope is approximately 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.

 

[emmgjld]

obzpae

I think the easiest solution is a modular block system which incorporates Mechanically Stabilized Earth (MSE). There are quite a few systems available. Versalok being one that readily comes to mind. I don't recommend any one over others. A quick web search would provide a tremendous amount of information. The systems are relatively simple, can be adapted to access requirements (steps), a variety of styles are available and the various terraces could be constructed in stages. With a little care for drainage and planting, the terraces could be nicely landscaped. All designs incorporate susbsurface drainage, which could solve your water problem.

 

[ForestCity]

Be sure an use a geosynthetic to keep the fines from entering or worse yet exiting the reinforced zone. The use of an open graded stone of 12" behind the wall will also help relieve hydrostatic pressures.

 

[GeoffD]

A slope of 1 in 1 (45 degrees) sounds pretty steep for a slope in silty sands especially with groundwater present and may be borderline stable. Is the slope mainly bedrock and will the retaining walls involved supporting natural ground or fill?