addedsection02227.pdf

CHATTOOGA DISTRICT RANGER OFFICE ROCK REMOVAL

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SECTION 02227

ROCK REMOVAL

PART 1 GENERAL

1.01 SCOPE OF WORK

Removal of all rock materials discovered during excavation for the purpose of construction. Removal shall include drilling and/or blasting incidental thereto and disposal of excavated materials.

1.02 RELATED WORK

Section 02225 - Earthwork for Utilities

1.03 REFERENCES

A. NFPA 495 - Code for the Manufacture, Transportation, Storage, and Use of Explosive Materials.

B. OSHA 29 CFR Part 1926, Subpart T – Demolition, and Subpart U – Blasting and the Use of Explosives, latest revision.

1.04 QUALITY ASSURANCE

A. When necessary for prosecution of the WORK, the use of explosives to assist rock removal may be exercised by CONTRACTOR provided this use is in compliance with all local, State, Federal and other Governmental regulations applying to transportation, storage, use and control of explosives.

B. Explosives Firm: Company specializing in explosives for disintegration of subsurface rock with documented experience.

1.05 REGULATORY REQUIREMENTS

A. Conform to applicable code for explosive disintegration of rock, including NFPA 495 and OSHA 29 CFR Part 1926, Subparts T and U.

B. Obtain permits from authorities having jurisdiction before explosives are brought to site or drilling is started.

C. All explosives shall be stored securely in compliance with all laws and ordinances, and all such storage places shall be clearly marked DANGEROUS EXPLOSIVES. Blasting caps, electric blasting caps, detonating primers, and primed cartridges shall not be stored in the same magazine with other explosives or blasting agents. Locked storage shall be provided satisfactory to the ENGINEER, never closer than 1000 feet from any road, building, or camping area.

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PART 2 PRODUCTS

2.01 MATERIALS

A. Rock (Definition): Solid mineral material with a volume in excess of 1/2 cu yd that cannot be broken down and removed by use of heavy construction equipment, such as a Caterpillar 215C power excavator equipped with a short tip radius rock bucket, bulldozer such as a Caterpillar D9 equipped with single tooth hydraulic ripper, 3/4 cu yd capacity power shovel, rooters, etc., without drilling or blasting. Materials which can be loosened with a pick, hard pan, boulders less than 1/2 cu yd in volume, chert, clay, soft shale, soft and disintegrated rock and any similar material shall not be considered as rock. (All materials to be considered unclassified or common excavation)

B. Explosives: Shall be suitable for intended purposes at the CONTRACTOR's option subject to review by OWNER and ENGINEER.

C. Delay Devices: Type recommended by explosives firm to be used as accessory to explosives. Subject to review by ENGINEER.

D. Blasting Mat: When the use of explosives is necessitated during prosecution of the WORK, CONTRACTOR shall incorporate the use of blasting mats of type recommended by explosives firm to lessen the danger of projectiles occasionally resultant from blasting of rock.

PART 3 EXECUTION

3.01 INSPECTION

A. CONTRACTOR shall verify site conditions and note irregularities affecting work of this Section prior to performing any operations involving explosives. CONTRACTOR shall submit to OWNER for review a detailed plan for using explosives to include, but not limited to:

1. Sequence of WORK

2. Equipment

3. Protection to be provided for existing structures to remain

4. Personnel

a) Training

b) Previous experience with the use of explosives in similar situation

B. Beginning work of this Section means acceptance of existing condition.

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C. Rock in utility trenches shall be excavated over the horizontal limits of excavation and to depths as follows:

Size of Pipeline (Inches)

Depth of Excavation Below Bottom of Pipe (Inches)

Less than 4 6

4 to 6 8

Over 8 12

Space below grade for pipe shall then be backfilled with bedding stone in accordance with Section 02225 or other approved materials and tamped to proper grade.

3.02 ROCK REMOVAL - MECHANICAL METHOD

A. Excavate for and remove rock by the mechanical method.

B. Where pipes are constructed on concrete cradles, rock shall be excavated to bottom of cradle as shown on plans.

C. Rock encountered during foundation or trench excavations shall be removed to allow placement of a minimum 12 inches of graded aggregate base course between the bottom of the footing or trench and the rock surface.

D. Rock excavation near existing pipelines or other structures shall be conducted with utmost care to avoid damage. Injury or damage to other structures and properties shall be promptly repaired to the satisfaction of OWNER and by CONTRACTOR at his own expense.

E. Rock excavation for all structures and adjacent trenches under this Contract and any other rock excavation directed by OWNER shall be completed before construction of any structure is started in the vicinity.

F. Remove excavated material from site.

G. CONTRACTOR shall correct unauthorized rock removal by backfill to grade with material in accordance with backfilling and compaction requirements of Section 02225 at his own expense.

3.03 ROCK REMOVAL - EXPLOSIVES METHODS

A. If rock is uncovered requiring the explosives method for rock disintegration and removal, the ENGINEER shall be notified immediately so that the surface can be examined. Blasting will not be permitted unless written authorization is given by ENGINEER. (All materials removed shall be considered common excavation).

B. The CONTRACTOR shall notify any owners of adjacent buildings or structures, and any public utility owners having structures or other installations above or below ground, in writing prior to use of explosives. Such notice shall be given sufficiently in advance so that they may take such steps as they

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may deem necessary to protect their property from injury and/or damage.

C. Rock excavation by use of explosives shall be conducted with due regard for safety of persons and property in the vicinity and in strict conformance with requirements of local, State and Federal ordinance, laws and regulations governing the use of explosives.

D. Blasting shall be conducted so as not to endanger persons or property, and whenever required, the blast shall be covered with mats or otherwise satisfactorily confined. The CONTRACTOR shall be held responsible for and shall make good any damage caused by blasting or accidental explosions.

E. The CONTRACTOR shall permit only authorized and qualified persons to handle and use explosives.

F. Smoking, firearms, matches, open flame lamps, and other fires, flame or heat producing devices and sparks shall be prohibited in or near explosive magazines or while explosives are being handled, transported or used.

G. No person shall be allowed to handle or use explosives while under the influence of intoxicating liquors, narcotics, or other dangerous drugs.

H. All explosives shall be accounted for at all times. Explosives not being used shall be kept in a locked magazine, unavailable to persons not authorized to handle them. The CONTRACTOR shall maintain an inventory and use record of all explosives. Appropriate authorities shall be notified of any loss, theft, or unauthorized entry into a magazine.

I. No explosives or blasting agents shall be abandoned.

J. CONTRACTOR's employees authorized to prepare explosive charges or conduct blasting operations shall use every reasonable precaution including, but not limited to, visual and audible warning signals, flags, or barricades, to ensure safety.

K. It shall be CONTRACTOR's responsibility to incorporate the use of seismic monitoring should rock excavation, by use of explosives, occur within 150 feet of any residential structure and within 300 feet of any miscellaneous structure. Blasting conducted near dams or bridge foundations shall incorporate the use of a seismic monitor should such blasting occur within 25 feet of said dam and/or bridge foundation. CONTRACTOR shall maintain all seismic records and blasting logs to be furnished to ENGINEER upon request.

L. Disintegrate rock and remove from excavation.

M. Cut away rock at excavation bottom to form level bearing.

N. Remove shaled layers to provide sound and unshattered base for pipe foundations.

O. Remove excavated material from site.

P. Correct unauthorized rock removal or overbreak in accordance with backfilling and compaction requirements at CONTRACTOR'S expense.

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3.04 FIELD QUALITY CONTROL

Provide for visual inspection of bearing surfaces and cavities formed by removed rock for inspection by ENGINEER or his representative prior to laying of pipe.

END OF SECTION