Section_31_23_18_-_Rock_Excavation_GRTE_149677_WATER.pdf

GRTE – 149677-WATER

31 23 18 - 1

ROCK EXCAVATION

SECTION 31 23 18 - ROCK EXCAVATION

PART 1 GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

1.2 SUMMARY

A. Section Includes:

1. Removing discovered rock during excavation.

2. Expansive tools to assist rock removal.

B. Related Sections:

1. Section 31 23 16 - Excavation

2. Section 31 23 17 - Trenching: Trenching and backfilling for utilities.

3. Section 31 23 23 - Fill: Backfill materials.

1.3 DEFINITIONS

A. Solid Rock: Large masses of rock which, in the judgment of the Contracting Officer’s Representative, cannot be excavated without additional specialized equipment such as pneumatic chisels, hydraulic hammer, ripping, rock saw, etc. Solid Rock shall be described as solid masses that are homogeneous, interlocking crystalline material with firmly cemented, laminated, or foliated masses or conglomerate deposits, considered “hard material” as determined by the Contracting Officer (CO).

B. Loose Rock: Boulders and other detached stones that cannot be removed from the trench or excavation with a track excavator larger than the latest model of a Caterpillar Model 325B L equipped with rock bucket, or equal.

C. This description is for classification purposes only. Excavated materials will be classified as rock only if it is in accordance with all of the following conditions:

1. Rock shall be described as solid masses that are homogeneous, interlocking crystalline material with firmly cemented, laminated, or foliated masses or conglomerate deposits, considered “hard material” as determined by the Contracting Officer (CO).

2. Excavation and removal of solid masses, as defined in item 1 above, which requires a track excavator larger than the latest model of a Caterpillar Model 325B L equipped with rock bucket, or equal.

a. Rock bucket: Entek Model 55, 36 inch, cast iron lip, three rock tooth configuration, or equal.

b. Excavator must be operated by a person experienced in rock excavation similar to project conditions encountered.

3. The Contractor may use a larger excavator than a Caterpillar Model 325B L for excavation.

However, for materials to be classified as “rock”, the Contractor is required to demonstrate that the material cannot be excavated by a Caterpillar Model 325B L, larger excavator, or

31 23 18 - 2 equal. In the event a disagreement arises regarding classification of material in conjunction with larger, more powerful excavation equipment, the CO reserves the right to require the Contractor to mobilize a Caterpillar Model 325B L or equal, and to conduct excavation of the material in question. If the material is excavatable, the mobilization and demonstration cost for the Caterpillar Model 325B L or equal will be incurred by the Contractor. If it is determined that the material is not excavatable by a Caterpillar Model 325B L, or equal, the Government will pay cost for mobilization and demonstration of the equipment.

c. Hard materials that require excavation and removal with track excavator larger than specified above, or hard materials that require excavation and removal with systematic drilling, drilling and the use of expansion jacks or feather edges, or the use of backhoe-mounted pneumatic hole punchers or rock breakers will be classified as “rock”.

d. Contractor is responsible for demonstrating, to the satisfaction of the CO, that the track excavator specified above is not capable of excavating the material and that the excavated material will need to be classified as “rock” by the CO.

e. Contractor shall notify CO when “rock” is encountered. CO will authorize “rock” removal prior to beginning rock excavation.

D. Earth: All material not classified as rock, including all rock, stones, or boulders that can be reasonably broken, plowed, or removed with the power driven equipment described above. No additional payment or modifications will be made for the excavation of “earth.”

1.4 SUBMITTALS

A. Section 01 33 23 - Submittal Procedures: Submittal procedures.

B. Shop Drawings: Indicate intended rock removal method and equipment.

C. Survey Report: Submit survey report on conditions of buildings near locations of rock removal.

1.5 SCHEDULING

A. Section 01 31 00 – Project Management: Coordination and project conditions.

B. Schedule Work to avoid disruption to occupied buildings nearby.

PART 2 PRODUCTS

Not Used.

PART 3 EXECUTION

3.1 EXAMINATION

A. Section 01 31 00 – Project Management: Coordination and project conditions.

B. Verify site conditions and note subsurface irregularities affecting Work of this section.

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3.2 PREPARATION

A. Identify required lines, levels, contours, and datum.

3.3 ROCK REMOVAL BY MECHANICAL METHOD

A. Excavate and remove rock by mechanical method.

1. Drill holes and use expansive tools and wedges to fracture rock.

B. Cut away rock at bottom of excavation to form level bearing.

C. Remove shaled layers to provide sound and unshattered base for footings and foundations.

D. In utility trenches, excavate to 6-inches below invert elevation of pipe and 12-inches wider than outside diameter of the pipe.

E. Remove excavated materials from site, or reuse for site landscaping including riprap revetments and retaining walls.

F. Correct unauthorized rock removal by backfilling with suitable on site material or granular fill as directed by the CO.

1. Deposited fill in compacted lifts not to exceed eight inches in thickness, and mechanically compacted to at least 95% of maximum density as determined by ASTM D698 (Standard Proctor).

G. Excess rock material not suitable for embankment, backfill or revetment shall be removed and disposed of off NPS Lands at an approved location and in a lawful manner.

3.4 FIELD QUALITY CONTROL

A. Trenches: One in-place compaction test as specified in ASTM D2922-96e1 and ASTM D3017- 96e1 for every 100 lineal feet of trench in the compacted embedment zone and at every 1½ feet of vertical lift of backfill materials. In addition, complete a minimum of two per location, or one in-place compaction test every 100 lineal feet on final surface of compacted subgrade and base course located in roads, sidewalks or other travel ways.

B. Foundations: Complete compaction tests as specified in ASTM D2922-96e1 and ASTM D3017- 96e1 in over excavated areas.

1. Test every 400 square feet and every 1½ feet of vertical lift.

C. Request visual inspection of foundation bearing surfaces by CO before installing subsequent work.

END OF SECTION 31 23 18