(A) Before any excavation is begun, the excavator shall make provisions to re-route traffic, if necessary, shall place flags and barriers, or flares if at night, and in case of a deep excavation or excavation in loose material, shall be equipped to shore up the sides of the excavation with trench jacks or cribbing.
(B) All safety devices and precautions for work on state routes shall be in strict accordance with current specifications and regulations of the state’s Department of Highways.
(C) The paving to be removed shall first be scored with a scoring tool. It shall then be broken with a paving breaker. The cut through the paving shall be vertical and shall be squared to include the area to be removed. Paving shall be removed a minimum of six inches and a maximum of one foot beyond the edge of the proposed trench.
(D) (1) The width of the trench shall be no wider than is required for the work to be done, with allowance for shoring, when necessary. The walls of the trench shall be vertical. The length of a transverse trench shall be limited to one-half of the roadway width. In the case of three or more lanes of paving, this may be extended to two-thirds of the roadway.
(2) If absolutely necessary to repair or install a facility in one length, across the entire width of the roadway, a combination of open trench and tunneling will be permitted, if the applicant agrees to backfill the tunnel with gunite sand, concrete or other material as may be approved by the City Engineer.
(E) If the excavation has been made in basically granular native soil, it may be backfilled with the material removed, compacted by flooding or by tamping while moist. In the case of deep trenches in native soils which are not granular, the excavation may be backfilled with sand and gravel, suitably compacted, to a level just below the frost penetration. The remainder of the excavation will then be backfilled with native soil, as specified in division (G) below.
(F) When the excavation has exposed city-owned storm or sanitary sewers, the initial lift to the top of pipes larger than 24 inches’ nominal diameter, or to one foot above the top of smaller pipes, shall be placed and compacted as follows.
(1) Selected granular material shall be placed by hand or by suitable equipment in such manner as not to disturb the pipe. Such material shall not include any rocks larger than two inches in the maximum dimension, hard or frozen lumps which could damage the pipe.
(2) This material shall be compacted with mechanical tampers in four-inch layers.
(G) The remainder of the trench shall then be backfilled as follows. Native soil free from frozen lumps and vegetable matter shall be placed in six-inch layers and compacted with power equipment. The degree of compaction shall be such that there will be no appreciable settlement of the finished fill. The excavation shall be filled thusly to the level of the existing subgrade.
(Ord. 1019, passed 9-14-1964)