Re: retaining wall proposal Retaining Structures are interesting structures. It differs a lot. In reinforced concrete structures, the shoe system is important, I practically saw the following about 3-5 m heights; The rear shoe length becomes close to half the height. But when the height exceeds 6 m, my first suggestion is to do it gradually. As İbrahim Bey said, it is necessary to make threaded and vertical ribs at the base. In this way, wall thicknesses and rear shoe lengths can be reduced. I would suggest a pile system if it is 15 meters or something like yours. No, if no piles will be made, I applied a method similar to what you mentioned. Earth concrete geotextile wall construction. The basis is as follows; Mesh reinforcement is first laid on the floor, (the reinforcement goes out of the wall a little and bends upwards), a geotextile plastic-based filiform fibrous material is laid on it. felt is laid. A coating that allows ivy or grass to grow can be applied to the vertical surface of the wall to be decorative. This process is continued by compacting the soil with a thickness of 50-70 cm. In this way, we built slopes up to 15 m high and normally inconsistent. Of course, the basis of this is based on the principle of holding the ground itself by emptying its back and staggering and compacting it as I just mentioned. Frankly, I wouldn't recommend a 15m retaining wall. It is both difficult to manufacture and costly. There are also earth-concrete structures applied on some highways.