20180936 Ver 1_02202_20180705

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SECTION 02202

EXCAVATION BY BLASTING

PART 1 -- GENERAL

1.01 THE REQUIREMENT

A. Furnish all labor, equipment and materials required to drill, blast, loosen, excavate, and
dispose material to complete the work shown on the Drawings and specified herein.

B. The work shall include, but not be limited to:

1. Blast round design.

2. Planning and execution of appropriate site-specific safety measures to be
employed during all blasting operations, and the safe handling and storage of
high explosives and blasting agents.

3. Drilling blast holes, loading blast holes with explosives, and wiring and safe
detonation of blast rounds.

4. Removal from the site of all excess excavated soil, debris, and rock as indicated
in the Contract Documents, or as directed by the Engineer, and disposal of
excess materials at a permitted disposal site.

5. Dewatering and maintenance of groundwater and surface water in all
excavations.

6. Performance of all surveys necessary to establish and verify the lines and
grades, and to determine the amount of material removed.

7. Implementation of monitoring program to monitor condition of existing structures
and utilities in vicinity of proposed blasting operations to insure existing features
remain undamaged by blasting procedures.

C. All excavations shall be in conformity with the lines, grades, and cross sections shown
on the Drawings or established by the Engineer.

D. It is the intent of this Specification that the Contractor conduct the construction activities
in such a manner that erosion of disturbed areas and off-site sedimentation be
absolutely minimized, both at the excavation site and at the disposal site, as well as
along any haul routes used.

E. Rock excavation by blasting is prohibited within the CSX Railroad right-of-way.

1.02 RELATED WORK SPECIFIED ELSEWHERE

A. Section 02100 – Clearing, Grubbing, and Site Preparation
082905BR

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B. Section 02200 – Earthwork

C. Section 02276 – Erosion and Sedimentation Control

1.03 REFERENCE SPECIFICATIONS, CODES, AND STANDARDS

A. North Carolina Occupational Safety and Health Standards in Construction for Blasting &
Use of Explosives.

1.04 SUBSURFACE CONDITIONS

A. Reference is made to investigation reports of subsurface or latent physical conditions at
the site or otherwise affecting performance of the work which have been relied upon by
Engineer in preparing the Drawings and Specifications.

B. Attention is directed to the fact that there may be other water pipes, storm drains, sewer
lines, electric conduits, and other utilities located in the area of the proposed excavation.
Contractor shall perform all repairs to same in the event that excavation activities should
disrupt service.

1.05 SUBMITTALS

A. In accordance with the procedures and requirements set forth in Section 01300 -
Submittals, the Contractor shall submit the following at least 30 working days prior to
beginning any blasting operations:

1. Names, addresses, telephone numbers, and qualifications of the blasting
subcontractor(s) and explosives supplier(s) that will be used, including the
designated Blaster-In-Charge.

2. Copies of Training Certificates for the designated Blaster -In-Charge, blasting
foreman and any other key personnel that will be responsible for the work,
showing that they have received specialized training in the proper handling of
explosives.

3. A Blasting Plan, indicating the methods, materials and equipment to be used.
The Blasting Plan should indicate the types of explosives to be used, drilling
patterns, and a general layout and schedule for executing the work in
accordance with state regulations.

4. A ground vibration and air blast monitoring plan, indicating structures that will be
monitored, monitoring equipment that will be used, and personnel that will
perform the monitoring.

B. At least 24 hours before each blast round, Contractor shall submit a detailed blast round
design plan to the Engineer’s on-site representative. The blasting plan submitted is for
quality control and record keeping purposes. Review by the Engineer shall not relieve
the Contractor of his responsibilities as provided herein. The blast round design
submittals shall include:

1. Location (state, grid coordinates) and limits of the shot.

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2. Number, diameter, and depth of blast holes to be detonated in the round, and a
plan showing the drill hole pattern, spacing and distance to the free face.

3. Depth of overburden.

4. Total weight of explosives in the round and the types of explosives to be used.

5. Loading diagram showing the location of explosives, primers, and initiators; and
location, depth, and type of stemming to be used in each hole.

6. Initiation sequence, including delay timer and delay system, total weight of
explosive to be detonated on each delay, and a list of the timing of the delays.

7. Manufacturer’s data sheet for all explosives, primers, and initiators to be used.

8. Planned seismic monitoring positions, distances from the blast round, and
seismograph types to be used to monitor vibrations and air blast overpressures.

9. Type and amount of blasting mats and/or depth of soil cover to be used over the
top surface of the shot.

10. Any other information required by applicable state and federal regulations.

C. Within 24 hours after each blast round, Contractor shall submit a blasting report to the
Engineer. The blasting report shall include:

1. Date and time of shot.

2. Foreman’s name.

3. Number and depth of holes detonated.

4. Weather conditions at the time of detonation.

5. Type of explosives and detonators used.

6. Peak particle velocity of ground motion and primary frequency for all ground
vibration monitoring stations.

7. Peak air blast overpressure measured.

8. Distance from the blast round to each monitoring station for vibrations and air
blast.

9. Amount of explosive used in each hole, and maximum weight of explosive
detonated on any single delay in the blast round.

1.06 USE OF EXPLOSIVES

A. When the use of explosives is necessary for the prosecution of the work, the Contract or
shall exercise the utmost care not to endanger life or property. The Contractor shall be

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responsible for any and all damage or injury to persons or property resulting from the
use of explosives.

B. All explosives shall be stored in a secure manner, in compliance with all laws, and all
such storage places shall be marked clearly "DANGEROUS EXPLOSIVES".

C. The Contractor shall notify any public utility company having facilities in close proximity
to the site of the work of his intention to use explosives. This notice shall be given
sufficiently in advance to enable the utility companies to take whatever steps they may
consider necessary to protect their property from injury. The Contractor shall also give
the Engineer, all occupants of adjacent property, and all other Contractors working in or
near the Project, notice of his intention to use explosives.

PART 2 -- PRODUCTS

2.01 MATERIAL REQUIRING EXCAVATION BY BLASTING

A. Refer to Section 02220, Paragraph 1.04.B, for definition of rock.

2.02 INITIATORS

A. Contractor is advised of the possible presence of high-voltage electric power lines and
radio towers at the project site. Only non-electric type initiators may be used.

PART 3 -- EXECUTION

3.01 BLASTING OPERATIONS

A. Explosives shall be of such quantity and power and shall be used in such locations as
will neither open seams nor otherwise disturb the material outside the prescribed limits
of excavation. As the excavation approaches its final limits, the depth of holes for
blasting and the amount of explosives used for each hole shall be reduced so that the
underlying or adjacent rock will not be disturbed or shattered.

B. BLASTING SHALL NOT BE PERFORMED WITHIN 100 FEET OF NEWLY PLACED
CONCRETE THAT HAS CURED LESS THAN 7 DAYS. NO BLASTING SHALL BE
PERMITTED WITHIN 50 FEET OF ANY EXISTING STRUCTURE OR ANY NEW
STRUCTURE IN PROGRESS.

3.02 BLAST MONITORING

A A pre-construction condition inspection and documentation of adjacent structures on-site
and off-site shall be performed by the Contractor. The Contractor shall exercise the
utmost care not to damage property on-site and off-site. The Contractor shall notify
each adjoining property owner within 2500 feet of the site of the anticipated ground
vibrations and noise which will occur due to his blasting operations. This notice shall be
given 30 days in advance to enable the adjacent property owners to take whatever
precautions they may consider necessary. The Contractor shall limit his operations to
minimize any disturbance to the adjacent property owners. Motorists on adjacent
roadways shall be notified in accordance with state regulations. The Contractor shall be

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responsible for any damage to any structure or utility line, pipes, etc., on-site and off-site
as a result of his operations.

B. For each blast round, Contractor shall monitor and record noise and air blast
overpressures at the site perimeter nearest the blast location and at the on-site or off-
site structure located nearest to the round. Peak air blast overpressure shall not exceed
0.018 psi, measured at the site perimeter.

C. The site of every blast round shall be sufficiently covered with blasting m ats or other
devices to prevent any flying debris. The number and type of blasting mats must be
satisfactory to the Engineer. The Contractor will be fully responsible for any damage
caused by flying debris, both to on-site and off-site properties.

D. Whenever blasting is to be performed within 2500 feet of any structure, the Contractor
shall measure the peak particle velocities of ground vibration resulting from each blast at
the structure. Vibrations shall be monitored utilizing a seismograph capable of providing
a record of particle velocity and frequency along three mutually perpendicular axes
utilizing internal calibration. Measured peak particle velocity of ground motion at the
monitored structure shall not exceed the values shown in the following graph:

- END OF SECTION -

0.1
1
10
1 10 100Peak Particle Velocity (in/sec)Frequency (Hertz)
ACCEPTABLE
UNACCEPTABLE
0.5
2.0 inch/sec
0.19

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