retaining wall

What purpose does the retaining wall serve? Are there any additional loads placed above the wall thatbear on the retained soil? What is the slope of the soil retained behind the wall? What type of soil is behind the wall,a dn waht are the soil characteristics, eg unit weight, shear strength, cohesive strength? are there any shearing planes that could cause the soil to slide and fully load the wall? How much room do you need the slope set back? What will the final slope behind the structure look like? 65 degrees is a very steep slope. For every foot set back, you will have 2.14 feet of height. Also at that kind of an angle, it is likely that residuum parent material is relatively shallow and could form a slippage plane for the soil to move on. Under this circumstance the wall would retain more than the typical lateral loads from soil.

If the wall height is more than about 2 to 3 feet or serves as a structural support or protective structural member, you may need to contact a local civil engineer and have them design the wall. You may need a building permit also.

This is my home/lot distribution, the slope is approx. 30 ft. high, I want to build tiers on the slope, the area where I live is not prone to flooding get normal rain, approx. 9-13 inches per year. My original questions were not nor have been answered, I guess people were fixed on the picture of a steep slope and not on what I wanted to know. I have a retaining wall in place, wanted to know how much the 6x6 redwood logs would support and the distance between each log for maximum efficiency, dug holes at about 18-20 in. deep and created a raised bed of approx. 2-2.5 ft. ( lower one), I have not decided for the next level(tier). I do not know, but would like to, the relation between hight, length, angle of slope and also what impact does deep rooted trees play? I already finished the first tiers/level.