building a 35 - 36m long retaining wall where cars will be parking

To retain the wall should be at base half the height The way I would do it is a cantilever footing where the wall is 900 wide at the bottom then steps in from the back 10mm bar standing in the footings connects to the steel in the footings then hollow blocks over the steel and filled with concrete,also allow for drainage Best regards Anthony

Or the other option is to gabion the ground and backfill to ground level the gabion would be more than sufficient to retain and support the elevated ground level and with the correct installation would provide sufficient ground drainage and prevent hydrostatic pressure.

a 9 inch wall with 18 inch reinforced piers ,3 mtr centres for the piers . 2 x12 gauge steel bars inside the 18 inch piers.and concreted in as the wall is built. making sure the are in the concrete footing at the right intervals ,before the wall is built. with addition of brick tor (wire). running through the wall. it would be best every 3 course if the blocks are laid flat.also you should make provision for expansion joints through the wall.on that wall every second pier. you would need a land drain at the back of the wall. making sure that the pipe is separated from the backfill by a geotextile material and drainage through the wall at the appropriate intervals. the retaining wall on my profile photos was built the same way but faced off with a single skin brick wall.. best of luck kevin

If you’re building a retaining wall that the public will pass by or park their cars near, the wall should be designed and calculated by a structural engineer.