In all areas described in subsections (a) and (b) of Section 1325.09, retaining walls shall be designed and constructed as follows:
(a) General. Walls built to retain or support the lateral pressure of earth or water or other superimposed loads shall be designed and constructed of approved masonry, reinforced concrete, steel sheet piling or other approved materials within the allowable stresses of accepted engineering practice.
(b) Design. Retaining walls shall be designed to resist the pressure of the retained material, including both dead and live load surcharges to which they may be subjected, and to insure stability against overturning, sliding, excessive foundation pressure and water uplift.
(c) Hydrostatic Pressure. Unless drainage is provided, the hydrostatic head of water pressure shall be assumed equal to the height of the wall.
(d) Coping. All masonry retaining walls other than reinforced concrete walls shall be protected with an approved coping.
(e) Foundation Walls. Foundation walls of buildings and structures which serve as retaining walls shall conform to the above requirements or shall be strengthened with buttresses or additional wall thickness to resist lateral soil and hydrostatic pressure when subjected thereto. (Ord. 17-1980. Passed 5-5-80.)