This term shall consist of all grading above or below subgrade elevations, of whatever nature, required to bring the street to the proper subgrade elevation, including necessary excavation for curb, gutter, sidewalk, construction of embankments, excavation and proper sloping of all cuts, and other work incidental thereto.
(A) Excavations. All excavations shall be made to approximate subgrade elevations and shall be true to grade. No excavation shall be made below subgrade elevation except to remove a spongy material, vegetable matter or other material as ordered or approved by the inspector, or his or her duly authorized representative. In the event the contractor does excavate any other area below subgrade elevation, he or she shall replace the excavated material with satisfactory material and shall thoroughly compact same.
(B) Excavation below subgrade. Whenever excavation below subgrade elevation to remove spongy material, vegetable matter or other material is required, the contractor shall remove same in a satisfactory manner, and shall replace it with satisfactory material in layers not to exceed 12 inches in thickness and shall thoroughly compact each layer before the next layer is placed.
(C) Construction of embankments.
(1) All top soil shall be removed to eliminate all vegetation from the area upon which embankment is to be constructed. Soil so removed may not be used in construction of embankment.
(2) Embankment shall be constructed, of approved materials, to approximate subgrade elevation in layers to not exceed 12 inches in thickness and extending the full width of the embankment. Each layer shall be compacted to not less than 92% of the density determined from the Standard Test for Moisture-Density Relationship (AASHO Designation T-99) in areas involving structures and public improvements including slopes greater than 3:1.
(D) Subgrade preparation.
(1) The subgrade shall be in a moist condition at the time the paving course is placed. It shall be thoroughly wetted a sufficient time in advance of the placing of the concrete to ensure that there will be no puddles or pockets of mud when the concrete is placed. The subgrade, however, shall not be allowed to dry out before the paving course is placed.
(2) The subgrade soils shall be of uniform material and density to provide for satisfactory pavement performance. Soft spots that show up during construction should be excavated and recompacted with the same type of material as found in the adjacent subgrade. Uniform support cannot be obtained merely by dumping extra granular material on the soft spot. With a uniform subgrade, excessive shrink and swell of expansive soils shall be prevented by adequate moisture and density controls during compactions. The compaction percent of the density determined from the Standard Test for Moisture-Density Relationship (AASHO Designation T-99) will effectively control shrinking and swelling during periods of dry weather, providing the subgrade is not allowed to dry before the pavement is constructed. Concurrent with compaction, the subgrade shall be shaped to plan elevation, grade and cross-section. Special care shall be taken in compacting the backfill of sewers, drainage facilities and other permanent structures that may be in the paved area.
(3) Immediately prior to placing the paving course, the subgrade shall be tested for conformity with the cross-section shown on the plans by means of an approved template riding on the side forms. If necessary, material shall be removed or added, as required, to bring all portions of the subgrade to the correct elevation. It shall then be thoroughly compacted and again tested with the template. The paving course shall not be placed on any portion of the subgrade which has not been tested for correct elevation. The subgrade should also be cleared of any loose material which may have fallen on it.
(E) Equipment for compaction of embankment and subgrade. Any compaction equipment capable of uniformly producing the required embankment and subgrade densities, without lamination of, or within, successive layers, will be permitted. All compaction equipment shall be in good condition and shall be operated efficiently to assure uniform compaction.
(F) Subgrade for curbs, gutters, sidewalks and driveways. Subgrade areas to be occupied by curbs, gutters, sidewalks and driveways shall be excavated, backfilled as required, and compacted to establish grade. This work shall be done with particular care in accordance with all requirements herein.
(G) Equipment operated on the streets. The contractor shall be permitted to operate only pneumatic-tired equipment over any paved street surfaces and shall be responsible for correction of any damage to street surfaces in any manner resulting from the contractor’s operations.
(H) Protection of utility lines. The contractor shall at all times take proper precautions for the protection of utility lines, the presence of which are known, or can be determined by the examination of appropriate maps of applicable agencies and legislative body or fiscal court.
(1984 Code, Ch. 157, App. B, § 2) (Ord. O-86-78, passed 8-17-1978) Penalty, see § 157.999