513 EM 385-1-1 Chapters 23-29

Sections

29-8. General Requirements.

Electromagnetic Radiation

Avoid blasting or storing electric detonators near operating RF transmitters or RF devices unless IME SLP-20 clearances are met.
Utilize an approved non-electric initiation system for blasting, following the manufacturer's instructions and system requirements.

Vibration and Damage Control

Plan blasting operations near structures like cofferdams or buildings with thorough consideration of all forces and conditions.
Prepare a written plan for monitoring prior to starting vibration-controlled blasting, and inform owners, occupants, and the public about the nature and controls of the blasting operations as per local regulations.
Limit energy ratios and peak particle velocities to state or NFPA 495 standards, unless an exception is approved based on a safe and damage-free engineering analysis. Suspend blasting if limits are exceeded and notify relevant authorities and parties.

Drilling and Loading

Do not drill in an area already blasted until remaining "bootlegs" are examined for unexploded charges and the total area has been examined to make sure that there are no unexploded charges remain. The Blaster-in-Charge supervises drilling to neutralize misfires.
Separate drilling and loading areas by a safe distance, avoid disturbing loaded holes, and maintain the blast site free from unnecessary equipment or personnel.
Load only those holes that will be fired in the next round of blasting. After loading, immediately return all remaining explosive materials and detonators to an authorized magazine. Do not leave explosive materials or loaded holes unattended at the blast site at any time.

Knowledge Check Choose the best answer for the question.

29-8. During blasting operations, load only those holes that will be fired _____.

within intersecting holes

in the same undisturbed area

in the next round of blasting

in remaining "bootlegs"

You forgot to answer the question!

EM 385-1-1 Paragraph 29-8 (i.–k.).

29-8. General Requirements. (i.–k.).

i.  Electromagnetic Radiation.  (29-8.i)

(1)  Do not perform blasting operations or store electric detonators in the vicinity of operating RF transmitters or other RF producing devices, except where the clearances according to IME SLP-20 can be maintained.

(2)  Use an approved non-electric initiation system when performing blasting operations according to the manufacturer’s instructions and system requirements.

j.  Vibration and Damage Control.  (29-8.j)

(1)  Carefully plan, with full consideration of all forces and conditions involved, blasting operations in or adjacent to cofferdams, piers, underwater structures, buildings, structures, or other facilities.

(2)  Establish a written plan for monitoring the operations prior to initiating vibration-controlled blasting operations (see para 29-7.c).

(3)  Notify owners, occupants, and the public of the nature of blasting operations to be undertaken and controls that will be used as required by state and local ordinance.

(4)  Where vibration damage may occur, limit the energy ratios and peak particle velocities to the levels set by the states or included in the NFPA 495 requirements, whichever is more stringent.  An exception may be granted when approved by the USACE supervisor or accepted by the KO or COR; if an approved engineering analysis demonstrates that the proposed vibration exceedance will not cause damage and is safe.  Suspend blasting when any recording exceeds either the energy ratio or peak particle velocity limits. Immediately notify the local SOHO, Blasting SME, USACE supervisor, KO or COR, and contractor designated authority (if applicable) of the exceedance and do not resume blasting until the cause has been determined and corrective measures taken.

(5)  Where required by state regulations, determine scaled distances before each shot and included in the records.  Do not exceed the scaled distances limitations set by the state.

(6)  Do not exceed 133 dB (0.013 psi) air blast pressure on structures unless an engineering analysis, approved by the USACE supervisor or accepted by the KO or COR, demonstrates that the proposed air blast exceedance will not cause damage and is safe.

(7)  A QP must monitor, record, and interpret the vibrations.  Furnish a copy of records and interpretations to the USACE supervisor/KO or COR.

(8)  Use vibration and/or air blast measuring equipment specifically designed and manufactured such purpose.

(9)  Use appropriate blast holes patterns, detonation systems, and stemming to prevent venting of blasts and to minimize air blast and noise levels produced by blasting operations.

k.  Drilling and Loading.  (29-8.k)

(1)  All drill holes must be large enough to freely allow for the insertion of the explosives.

(2)  Do not drill in an area already blasted until remaining "bootlegs" are examined for unexploded charges and the total area has been examined to make sure that there are no unexploded charges remain.

(a)  Never insert a drill, pick, or bar into bootlegs even if examination fails to disclose explosives.

(b)  Do not drill holes where there is a danger of intersecting an undetonated hole, such as in an area where misfires have occurred.

(c)  The Blaster-in-Charge must supervise drilling performed to neutralize misfires. The Blaster-in-Charge must be familiar with the conditions under which the misfired holes were drilled, loaded, primed, and initiated and with the drilling equipment capabilities that will be used during the neutralization.

(3)  Do not conduct drilling and loading operations in the same area.  Separate drilling from loaded holes by at least the depth of the loaded hole, but in no case less than 50 feet (15.2 m).

(4)  Do not deepen drill holes that have contained explosives or blasting agents.

(5)  Do not drill where a loaded hole might be disturbed or intersected.

(6)  See chapter 18 for earth drilling requirements.

(7)  Keep the blast site free of any equipment, operations, or persons not essential to loading. Do not permit vehicle traffic over loaded holes.  Guard or barricade the blast site and post with danger signs to restrict unauthorized entry.

(8)  Load only those holes that will be fired in the next round of blasting.  After loading, immediately return all remaining explosive materials and detonators to an authorized magazine. Do not leave explosive materials or loaded holes unattended at the blast site at any time.

(9)  Do not load sprung or jet-pierced holes until it is established that the hole has cooled sufficiently to safely load.

(10) Do not load or use explosive underground in the presence of combustible gases or combustible dusts unless a CP certifies in writing that the conditions of use
    have been thoroughly identified and are safe. The CP must be qualified by a thorough knowledge of the factors to be evaluated or have been given written permission by the AHJ.

(11)  Do not make-up primers in advance.  Prime only the cartridges that will be used in the next round of blasting.

(12) Do not insert detonators in explosive materials that do not have a cap well without first making a hole in the cartridge with a non-sparking punch of proper size, or the appropriate pointed handle of a cap crimper.

(13)  Seat cartridges only by even steady pressure.

(14) Tamp with wood rods having no exposed metal parts.  Non-sparking metal connectors may be used for joint poles.  A plastic tamping pole, approved by the USACE supervisor or accepted by the KO or COR, may also be used.

(15)  Springing (that is, enlarging the bottom of a blasthole by firing a relatively small charge of explosive material) boreholes is prohibited.

(16)  Use of Detonating Cord.

(a)  Handle and use detonating cord with the same respect and care given other explosives, careful not to damage or sever cord during and after loading and hooking- up.

(b)  When using a detonating cord down line and after the primer is loaded in the hole, cut the detonating cord from the supply reel before loading the rest of the charge.

(c)  Detonating cord must be connected according to manufacturer’s recommendation. Only use knot or other cord-to-cord connections with detonating cord when the explosive core is dry.

(d)  All detonating cord trunk lines and branch lines must be free of loops, sharp kinks, or angles that direct the cord back toward the oncoming line of detonation.

(e)  When connecting a detonator to detonating cord, tape or otherwise secure attach the detonators along the side of the detonating cord, with the end of the detonator containing the explosive charge pointing in the direction in which the detonation is to proceed.

(f)  Do not bring detonators for firing the trunk line into the loading area nor attach them to the detonating cord until everything else is ready for the blast.

(17) The Blaster must keep an accurate, up-to-date record of explosives, blasting agents, and blasting supplies used in each blast.

(18)  Stem loaded holes to the collar with non-combustible material.

(19) Where blasting may cause injury or damage by flying rock or debris, cover all charges with blasting mats or back cover them before firing.  Where mats are used, take care to protect blasting lines.

(a)  If flyrock leaves the blast area, cease all blasting until a report is filed by a QP. The report must explain the cause of the flyrock and the methods that will be employed on all subsequent blasts to reduce the throw of flyrock.

(b)  If flyrock leaves the work site, cease all blasting operations until a QP reviews the blast site and determines the cause and solution to the flyrock program.  Before blasting proceeds, submit a written report to the USACE supervisor for approval or to the KO or COR for approval.