14.40.110 Fills.
A. General.
1. Unless otherwise recommended in the approved soils engineering report, fills shall conform to the provisions of this section.
2. In the absence of an approved soils engineering report, these provisions may be waived by the permit authority for minor fills not intended to support structures.
B. Fill Location. Fill slopes shall not be constructed on natural slopes steeper than two to one.
C. Preparation of Ground. The ground surface shall be prepared to receive fill by removing vegetation, noncomplying fill, topsoil and other unsuitable materials, scarifying to provide a bond with the new fill and, where slopes are steeper than five to one and the height is greater than five feet, by benching into sound bedrock or other competent material as determined by the soils engineer. The bench under the toe of a fill on a slope steeper than five to one shall be at least 10 feet wide. The area beyond the toe of fill shall be sloped for sheet overflow or a paved drain shall be provided. When fill is to be placed over a cut, the bench under the toe of fill shall be at least 10 feet wide but the cut shall be made before placing the fill and acceptance by the soils engineer or engineering geologist or both as a suitable foundation for fill.
D. Fill Material.
1. Organic material shall not be permitted in fills. Except as permitted by the building official, no rock or similar irreducible material with a maximum dimension greater than 12 inches shall be buried or placed in fills.
2. Exceptions. The permit authority may permit placement of larger rock when the soils engineer properly devises a method of placement, continuously inspects its placement and approves the fill stability. The following conditions shall also apply:
a. Prior to issuance of the grading permit, potential rock disposal areas shall be delineated on the grading plan.
b. Rock sizes greater than 12 inches in maximum dimension shall be 10 feet or more below grade, measured vertically.
c. Rocks shall be placed so as to assure filling of all voids.
E. Compaction. All fills shall be compacted to a minimum of 90 percent of maximum density as determined by the International Building Code (IBC) as adopted by the city. In-place density shall be determined in accordance with the IBC.
F. Slope. The slope of fill surfaces shall be no steeper than is safe for the intended use. Fill slopes shall be no steeper than two horizontal to one vertical.
G. Terracing. Terracing shall be provided and the area above fill slopes and the surfaces to terraces shall be graded and paved as required. See GHMC 14.40.130. (Ord. 1169 § 4, 2009).