2. GENERAL(a) A pre-construction su

2. GENERAL
(a) A pre-construction survey, which refers to the datum plane used in the approved plan, shall be
undertaken by the Contractor under the control of the Engineer to serve as a basis for the
computation of the actual volume of the excavated materials.
(b) All excavations shall be finished to reasonably smooth and uniform surfaces.
(c) No materials shall be wasted without authority of the Engineer.
(d) Prior to excavation, all necessary clearing and grubbing in that area shall have been performed in accordance with specification section 02100 “Site Clearing”.
3. CONSERVATION OF TOPSOIL
In accordance with the provisions of Specification section 02100 “Site Clearing”, suitable topsoil encountered in excavation and on areas where embankment is to be placed shall be removed to such extent and to such depth as the Engineer may direct. The removed topsoil shall be transported and deposited in storage piles at locations approved by the Engineer. The topsoil shall be completely removed to the required depth from any designated area prior to the beginning of regular excavation or embankment work in the area and shall be kept separate from other excavated materials for later use.
4. USE OF EXCAVATED MATERIAL
(a) All suitable material removed from the excavation shall be used in the formation of the Cohesive Slope Material, capping layer, embankment, subgrade, shoulders, slopes, bedding, surcharge and backfill for structures, and for other purposes shown on the Drawings or as directed by the Engineer.
(b) Any material surplus to these requirements, or any material declared in writing by the Engineer to be unsuitable, shall be disposed of by the Contractor outside the right-of-way or as directed by the Engineer in accordance with the provisions in the Sections 03000 and 03500 of the Specifications.
4.1 REMOVAL OF UNSUITABLE MATERIAL
The removal and disposal of unsuitable material shall be in accordance with Specification Section 03500.

ROCK EXCAVATION
Material shall be classified as “Rock Excavation” in the following case:
(a) When the material is evidenced to the Engineer, prior to commencement of excavation, to consist of material that cannot be excavated without blasting or the use of rippers (Single tine hydraulic ripper drawn by a tractor unit with a minimum weight of 40 tons and net horsepower rating of 285), including all boulder and detached stones have a volume of 1 m3 or more.
(b) When the material is declared in writing by the Engineer to be Rock Excavation.
All Excavation not evidenced to be Rock Excavation and declared in writing by the Engineer to be Rock Excavation, shall be deemed Common Excavation.
4.2.1 PRESERVING ROCK BELOW SUBGRADE
The Contractor shall take care not to break down, loosen or damage the rock under the subgrade line. Normally cuts will be made from the top; lift by lift, to protect the rock bench that will remain. The Contractor shall be responsible for methods used and for any damage caused to the roadbed, regardless of any previous approvals by the Engineer.
Materials classified as rock shall be excavated to a minimum depth of 150 mm and a maximum depth of 300 mm below subgrade within the limits of the roadbed. The excavation shall be backfilled and compacted with material designated in the Drawings and approved by the Engineer. Rock excavation removed in excess of 300 mm. below subgrade will not be measured and paid for. Backfill of the depth in excess of 300 mm below subgrade shall be at the Contractor's expense.
Undrained pockets shall not be left in the rock surface. Depressions shall be drained. The top of the rock slope pre-splitting line will be established by the Engineer. Bore holes shall be drilled along the slope line maintaining the drill holes at the angle designated on the plans and ensuring that all drill holes are in the same plane. The diameter, spacing, and loading of pre-split holes shall result in a neat break. The pre-splitting holes shall be drilled for the full depth of the ledge.
4.2.2 SCALING AND DRESSING
To leave rock cuts in a safe, stable condition, the Contractor shall scale and dress the slope, removing all loose fragments and rocks not firmly fastened to the rock slope. The Contractor shall also remove any overhanging rock the Engineer sees as a hazard to roadway users. If the Engineer requires it, the Contractor shall also remove loose fragments and rocks lying outside the slope stakes.