Additional Retaining wall for a steep slope
My wife and I just bought a house and I want to build a retaining wall behind an existing retaining wall. In the backyard is a fairly steep hill and we currently have no seating area, just a narrow gravel walkway that wraps around the house. There is a brick retaining wall that is approx. 3' high. What I want to do is, dig up a flat surface that is the height of the current retaining wall so that it can act as a sort of elevated patio.
My main question is, can I dig up and level off a platform(about 10' deep) and build another retaining wall behind and above the orginal 3' wall? My idea is that there would be one wall(the existing wall) about 6' from the house, and then you could step up onto that wall and there would be another wall 10' further out(which would be about 5' tall)
Would it even work, or would the second wall just topple over? If it would work, would I need to do anything to the area that will be used as a patio?