805 KAR 5:070. Minimum requirements for roof support and the roof control plan approval process

Link to law: http://www.lrc.ky.gov/kar/805/005/070.htm
Published: 2015

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      805 KAR 5:070. Minimum requirements for roof

support and the roof control plan approval process.

 

      RELATES TO: KRS 352.201

      STATUTORY AUTHORITY: KRS 351.070(13)

      NECESSITY, FUNCTION, AND CONFORMITY: KRS 352.201 requires

each underground coal mine to formulate and follow an approved roof control

plan. This proposed administrative regulation establishes those minimum

standards for roof support and the roof control plan approval process.

 

      Section 1. Definitions. The definitions established

in KRS 351.010 and 352.010 shall apply to this administrative regulation, in

addition to those set out below:

      (1) "Automated temporary roof support" or

"ATRS" means a mechanical device used to temporarily support the roof

while roof bolts are being installed.

      (2) "Automated temporary roof support

system" means the devices and mechanisms - including the ATRS - used, and

methods followed by which ATRS is activated and set to support the roof.

      (3) "Mining height" means the distance

between the bottom of the coal seam and the bottom of permanent mechanical roof

support, and specifically does not include or apply to the brushing of top or

bottom for construction work and to coal left unmined for purposes of providing

additional roof support.

      (4) "Pillar recovery" means any reduction

in pillar size during retreat mining.

      (5) "Roof control plan" means the plan

and its revisions which has been adopted by the licensee for support of the

mine roof and approved by the commissioner or his authorized representative

pursuant to KRS 352.201(1).

 

      Section 2. Mining Methods. (1) The method of mining

shall not expose any person to hazards caused by excessive widths of rooms,

crosscuts and entries, or faulty pillar recovery methods. Pillar dimensions

shall be compatible with effective control of the roof, face, ribs and coal or

rock bursts.

      (2) A sightline or other method of directional

control shall be used to maintain the projected direction of mining in entries,

rooms, crosscuts and pillar splits.

      (3) A sidecut shall be started only from an area

that is supported in accordance with the roof control plan.

      (4) A working face shall not be mined through into

an unsupported area of active workings, except when the unsupported area is

inaccessible.

      (5) Additional roof support shall be installed

where:

      (a) The width of the opening specified in the roof

control plan is exceeded by more than twelve (12) inches; and

      (b) The distance over which the excessive width

exists is more than five (5) feet.

 

      Section 3. Roof Bolting. (1) For roof bolts and

accessories addressed in American Society for Testing and Materials (ASTM, F

432-95), the licensee shall:

      (a) Obtain a manufacturer's certification that the

material was manufactured and tested in accordance with the specifications of

ASTM; and

      (b) Make this certification available to an

authorized representative of the commissioner.

      (2) Roof bolts and accessories not addressed in the

material incorporated by reference may be used, if the use of those roof bolts

and accessories is approved by the commissioner or his authorized representative

based on:

      (a) Demonstrations which show that the materials

have successfully supported the roof in an area of a coal mine with similar

strata, opening dimensions and roof stresses; or

      (b) Tests which show the materials to be effective

for supporting the roof in an area of the affected mine which has strata,

opening dimensions and roof stresses similar to those in the area where the

roof bolts are to be used; during the test process, access to the test area

shall be limited to persons necessary to conduct the test.

      (3) A bearing plate shall be firmly installed with

each roof bolt.

      (4) A bearing plate used directly against the mine

roof shall be at least six (6) inches square, except that if the mine roof is

firm and not susceptible to sloughing, bearing plates five (5) inches square

may be used.

      (5) A bearing plate used with wood or metal

materials shall be at least four (4) inches square.

      (6) Wooden materials that are used between a

bearing plate and the mine roof in an area which will be used for three (3)

years or more shall be treated to minimize deterioration.

      (7) When washers are used with roof bolts, the

washers shall conform to the shape of the roof bolt head and bearing plate.

      (8) The diameter of a finishing bit shall be within

a tolerance of plus or minus 0.030 inch of the manufacturer's recommended hole

diameter for the anchor used.

      (9) When separate finishing bits are used, they

shall be distinguishable from other bits.

 

      Section 4. Tensioned Roof Bolts. (1) Roof bolts

that provide support by creating a beam of laminated strata shall be at least

thirty (30) inches long. Roof bolts that provide support by suspending the roof

from overlying stronger strata shall be long enough to anchor at least twelve (12)

inches into the stronger strata.

      (2) Test holes, spaced at intervals specified in

the roof control plan, shall be drilled to a depth of at least twelve (12)

inches above the anchorage horizon of the bolts being used. When a test hole

indicates that bolts would not anchor in competent strata, corrective action

shall be immediately taken.

      (3) The installed torque or tension ranges for roof

bolts as specified in the roof control plan shall maintain the integrity of the

support system and shall exceed neither the yield point of the roof bolt nor

anchorage capacity of the strata.

      (4) In each roof bolting cycle, the actual torque

or tension of the first tensioned roof bolt installed with each drill head

shall be measured immediately after it is installed. Thereafter, for each drill

head used, at least one (1) roof bolt out of every four (4) installed shall be

measured for actual torque or tension. If the torque or tension of any of the

roof bolts measured is not within the range specified in the roof control plan,

corrective action shall be taken.

      (5) In a working place from which coal is produced

during any portion of a twenty-four (24) hour period, the actual torque or

tension on at least one (1) out of every ten (10) previously installed,

mechanically anchored, tensioned roof bolts shall be measured from the outby

corner of the last open crosscut to the face in each advancing section.

Corrective action shall be taken if the majority of the bolts measured:

      (a) Do not maintain at least the following percentages

of the minimum torque or tension specified in the roof control plan:

      1. Seventy (70) percent; or

      2. Fifty (50) percent if the roof bolt plates bear

against wood;

      (b) Have exceeded the maximum specified torque or

tension by fifty (50) percent.

      (6) The licensee or a person designated by him

shall certify by signature and date that measurements required by subsection

(5) of this section have been made. This certification shall be maintained for

at least one (1) year and shall be made available to an authorized representative

of the commissioner and representatives of the miners.

      (7) A tensioned roof bolts installed in the roof

support pattern shall not be used to anchor trailing cables or used for any

other purpose that could affect the tension of the bolt. The hanging of

trailing cables, line brattice, telephone lines, or other similar devices which

do not place a sudden load on the bolts is permitted.

      (8) An angle compensating device shall be used when

tensioned roof bolts are installed at an angle greater than five (5) degrees

from the perpendicular to the bearing plate.

      (9) The first nontensioned grouted roof bolt

installed during each roof bolting cycle shall be tested during or immediately

after the first row of bolts has been installed. If the bolt tested does not

withstand at least 150 foot-pounds of torque without rotating in the hole,

corrective action shall be taken.

 

      Section 5. Installation of Roof Support Using

Mining Machines with Integral Roof Bolters. When roof bolts are installed by a

continuous mining machine with integral roof bolting equipment:

      (1) The distance between roof bolts shall not

exceed ten (10) feet crosswise;

      (2) Roof bolts to be installed nine (9) feet or

more apart shall be installed with a wooden crossbar at least three (3) inches

thick and eight (8) inches wide, or material which provides equivalent support;

and

      (3) Roof bolts to be installed more than eight (8)

feet but less than nine (9) feet apart shall be installed with a wooden plank

at least two (2) inches thick and eight (8) inches wide, or material which

provides equivalent support.

 

      Section 6. Conventional Roof Support. (1) When

conventional roof support materials are used as the only means of support:

      (a) The width of any opening shall not exceed

twenty (20) feet;

      (b) The spacing of roadway roof support shall not

exceed five (5) feet;

      (c) Supports shall be installed to within five (5)

feet of the uncut face;

      (d) If supports nearest the face must be removed to

facilitate the operation of face equipment, equivalent temporary support shall

be installed prior to their removal;

      (e) A straight roadway shall not exceed sixteen

(16) feet wide where full overhead support is used and fourteen (14) feet wide

where only posts are used;

      (f) A curved roadway shall not exceed sixteen (16)

feet wide; and

      (g) The roof at the entrance of all openings along

travelways which are no longer needed for storing supplies or for travel of

equipment shall be supported by extending the line of support across the

opening.

      (2) Conventional roof support materials shall meet

the following specifications:

      (a) The minimum diameter of cross-sectional area of

wooden posts shall be as follows:



Post Length

(in inches)





Diameter of

round post

(in inches)





Cross-sectional

area

of split post

(in square

inches)







60 or less





4





13







Over 60 to 84





5





20







Over 84 to 108





6





28







Over 108 to 132





7





39







Over 132 to 156





8





50







Over 156 to 180





9





64







Over 180 to 204





10





79







Over 204 to 228





11





95







Over 228





12





113





      (b) Wooden materials used for support shall have

the following dimensions:

      1. Cap blocks and footings shall have flat sides

and be at least two (2) inches thick, four (4) inches wide and twelve (12)

inches long;

      2. Crossbars shall have a minimum cross-sectional

area of twenty-four (24) square inches and be at least three (3) inches thick;

      3. Planks shall be at least six (6) inches wide and

one (1) inch thick.

      (c) Cribbing materials shall have at least two (2)

parallel flat sides.

      (3)(a) A cluster of two (2) or more posts that

provide equivalent strength may be used to meet the requirements of subsection

(2)(a) of this section.

      (b) A post shall not have a diameter less than four

(4) inches or have a cross-sectional area less than thirteen (13) square

inches.

      (4) Materials other than wood used for support

shall have support strength at least equivalent to wooden material meeting the

applicable provisions of this section.

      (5) Posts and jacks shall be tightly installed on

solid footing.

      (6) If a post is installed under roof susceptible

to sloughing, a cap block, plank, crossbar or materials that are equally

effective shall be placed between the post and the roof.

      (7) Blocks used for lagging between the roof and

crossbars shall be spaced to distribute the load.

      (8) A jack used for roof support shall be used with

at least thirty-six (36) square inches of roof-bearing surface.

 

      Section 7. Pillar Recovery. (1) Full and partial

pillar recovery shall not be conducted on the same pillar line, except where

physical conditions such as unstable floor or roof, falls of roof, oil and gas

well barriers or surface subsidence require that pillars be left in place.

      (2) Before mining is begun in a pillar split or

lift:

      (a) At least two (2) rows of breaker posts or

equivalent support shall be installed as close to the initial intended

breakline as practicable and across each opening leading into an area where

full or partial pillar extraction has been completed; and

      (b) A row of roadside-radius (turn) posts or

equivalent support shall be installed leading into the split or lift.

      (3) Before mining is started on a final stump:

      (a) At least two (2) rows of posts or equivalent

support shall be installed on not more than four (4) foot centers on each side

of the roadway;

      (b)1. No more than one (1) roadway, which shall not

exceed sixteen (16) feet wide, shall lead from solid pillars to the final stump

of a pillar; and

      2. If posts are used as the sole means of roof

support, the width of the roadway shall not exceed fourteen (14) feet.

      (4) During open-end pillar extraction:

      (a) At least two (2) rows of breaker posts or

equivalent support shall be installed on not more than four (4) foot centers.

      (b) These supports shall be:

      1. Installed between the lift to be started and the

area where pillars have been extracted; and

      2. Maintained to within seven (7) feet of the face.

      (c) The width of the roadway shall not exceed

sixteen (16) feet.

      (d) If posts are used as the sole means of roof

support, the width of the roadway shall not exceed fourteen (14) feet.

 

      Section 8. Installation and Use of Automated

Temporary Roof Support Systems. This section establishes the requirements for

and criteria of automated temporary roof support in an underground coal mine in

which both the coal bed thickness and the mining height exceed thirty (30)

inches.

      (1) All roof bolting machines and continuous mining

machines with integral roof drills used in a working place in a coal mine shall

be provided with an approved automated temporary roof support system unless

other methods of temporarily supporting the roof have been approved by the

commissioner.

      (2) Automated temporary roof support systems and

all other methods of temporarily supporting the roof shall be approved on an

individual mine basis by the commissioner and shall become part of the roof control

plan required by KRS 352.201(1).

      (3)(a) The commissioner may grant a waiver of the

requirement for the use of an automated temporary roof support system if:

      1. It has been demonstrated by the licensee and

determined during an investigation by an authorized representative of the

commissioner that:

      a. The use of the system would create a greater

danger in areas where permanent supports have been installed than the method employed

or proposed for temporary support of the roof; or

      b. The technology of an automated temporary roof

support system does not exist to allow compliance with the requirements of

subsection (5) of this section;

      2. The configuration of the surface of the roof or

other conditions make the use of an ATRS system ineffective or impractical; or

      3. The licensee's present roof control plan

provides adequate safety to the miner due to the geology or condition of the

roof.

      (b) In granting a waiver, the commissioner may

approve the use of temporary jacks and posts in lieu of the ATRS.

      (4)(a) In the event of a mechanical breakdown in

the ATRS, the licensee shall:

      1. Provide for comparable temporary roof support;

      2. Immediately notify the commissioner or his

authorized representative of:

      a. The temporary roof support being used; and

      b. The provisions being made to repair or replace

the ATRS.

      (b) The commissioner or his authorized

representative shall order the removal of miners from the work area, if it is

determined that the roof support system being used during repair of the ATRS

does not adequately provide for their safety.

      (5) A machine using, or used as, an automated

temporary roof support system shall comply with the following minimum

requirements unless a waiver has been granted or another method of temporarily

supporting the roof has been approved by the commissioner, pursuant to

subsection (2) of this section:

      (a) The controls necessary to position the machine

and place the ATRS against the roof shall be operated from under permanently supported

roof, unless the design of the system provides adequate protection of the

miner;

      (b) The ATRS shall be placed firmly against the

roof prior to work inby the permanent roof supports and shall remain in place

while work is performed, unless the configuration of the roof surface prevents

uniform placement of the ATRS;

      (c) A hydraulic jack affecting the support capacity

of an ATRS shall have check valves or equivalent protection, to prevent support

failure if there is a sudden loss of hydraulic pressure;

      (d) An ATRS used in conjunction with single bolt

installation shall elastically support, at a minimum, a deadweight load of

11,250 pounds for each five (5) feet by five (5) feet square area of the roof

to be supported;

      (e) An ATRS consisting of pads or crossbars used in

single or multiple rows shall elastically support, at a minimum, a deadweight

load in pounds of 450 x ((L+5) x (W+5)), where L is the length of the support

structure from tip to tip and W is the width taken at the center line of a

support structure to the center line of another support structure;

      (f) The actual capacity of the ATRS to support

elastically a deadweight load shall be certified by a registered professional

engineer;

      (g) The distance that the ATRS may be set inby the

last row of permanent supports shall be dependent on the row spacing

requirements of the permanent roof supports and shall be authorized in the

approved roof control plan; and

      (h) A person shall not work or travel inby the

ATRS.

 

      Section 9. Manual Installation of Temporary

Support. (1) During manual installation of temporary support:

      (a) Only a person engaged in installing the support

shall proceed beyond permanent roof support;

      (b) The first temporary support shall not be set

more than five (5) feet from a permanent roof support and the rib.

      (2) A temporary support shall be:

      (a) Set so that the person installing the support

remains between it and two (2) other supports which shall not be more than five

(5) feet away;

      (b) Completely installed prior to installation of

the next temporary support;

      (c) Placed on no more than five (5) foot centers.

      (3) After temporary supports have been installed,

work or travel beyond the permanent roof support shall be between:

      (a) Temporary supports and the nearest permanent

support; or

      (b) Other temporary supports.

 

      Section 10. Warning Devices. Except during the

installation of roof supports, the end of permanent roof support shall:

      (1) Be posted with a readily visible warning; or

      (2) Have a physical barrier installed to impede

travel beyond permanent support.

 

      Section 11. Roof Testing and Scaling. (1) A visual

examination of the roof, face and ribs shall be made immediately before any

work is started in an area and during the workshift as conditions warrant.

      (2) If the mining height permits and the visual

examination does not disclose a hazardous condition, sound and vibration roof

tests, or other equivalent tests, shall be made where supports are to be

installed. If sound and vibration tests are made, they shall be conducted:

      (a) After the automated temporary roof support

system is set against the roof and before other support is installed; or

      (b) Prior to manually installing a roof support.

      (3) Sound and vibration roof tests, or other

equivalent tests, shall begin under supported roof and shall not progress

further than the location where the next support is to be installed.

      (4)(a) If a hazardous roof, face, or rib condition

is detected, the condition shall be corrected before work or travel is

conducted in the affected area.

      (b) If the affected area is left unattended, each

entrance to the area shall:

      1. Be posted with a readily visible warning; or

      2. Have a physical barrier installed to impede

travel in the area.

      (c) A bar for removing loose material shall be:

      1. Available in the working place; or

      2. On all face equipment, except haulage equipment;

and

      3. Of a length and design that will permit the

removal of loose material from a position that will not expose the worker to

injury from falling material.

 

      Section 12. Rehabilitation of Areas with

Unsupported Roof. (1) General rehabilitation plans shall be submitted with the

roof control plan.

      (2) Before rehabilitating an area where a roof fall

has occurred or the roof has been removed by mining machines or blasting:

      (a) The licensee shall establish the clean-up and

support procedures to be followed;

      (b) A person assigned to perform rehabilitation

work shall be instructed in the clean-up and support procedures; and

      (c) Ineffective, damaged or missing roof support at

the edge of the area to be rehabilitated shall be replaced or other equivalent

support installed.

      (3) A person performing rehabilitation shall be

experienced in that work or supervised by a person, designated by the licensee,

who is experienced.

      (4) If work is not being performed to rehabilitate

an area in active workings where a roof fall has occurred or the roof has been

removed by mining machines or by blasting, each entrance to the area shall be

supported by at least one (1) row of posts on not more than five (5) foot

centers, or equally effective support.

 

      Section 13. Supplemental Support Materials,

Equipment and Tools. (1) A supply of supplemental roof support materials and

the tools and equipment necessary to install the materials shall be available

at a readily accessible location on each working section or within four (4)

crosscuts of each working section.

      (2) The quantity of support materials, tools, and

equipment made available in accordance with this section shall be sufficient to

support the roof if adverse roof conditions are encountered, or in the event of

a roof fall.

 

      Section 14. Longwall Mining Systems. For each

longwall mining section, the roof control plan shall specify:

      (1) The methods that will be used to maintain a

safe travelway out of the section through the tailgate side of the longwall;

and

      (2) The procedures that shall be followed if a

ground failure prevents travel out of the section through the tailgate side of

the longwall.

 

      Section 15. Roof Control Plan. (1) When revisions

are proposed to the roof control plan required by KRS 352.201, only the revised

pages shall be submitted unless otherwise specified by the commissioner or his

authorized representative.

      (2) The licensee shall be notified in writing of

the approval or denial of a proposed roof control plan or proposed revision.

      (3) When approval of a proposed plan or revision is

denied, the deficiencies of the plan or revision and recommended changes shall

be specified and the licensee shall be afforded an opportunity to discuss the

deficiencies and changes with the commissioner or his authorized representative.

      (4) Before new support materials, devices or

systems other than roof bolts and accessories are used as the only means of

roof support, the commissioner or his authorized representative may require

that the effectiveness of those new support materials, devices, or systems be

demonstrated by experimental installations.

      (5) A proposed roof control plan or revision to a

roof control plan shall not be implemented before it is approved.

      (6) Before implementing an approved revision to a

roof control plan, a person who is affected by the revision shall be instructed

in its provisions.

      (7) The approved roof control plan and any revision

shall be available to the miners and representative of miners at the mine.

 

      Section 16. Roof Control Plan Information. The

following information shall be included in each roof control plan:

      (1) The name and address of the licensee;

      (2) The name, address, mine identification number

and location of the mine;

      (3) The name and title of the company official

responsible for the plan;

      (4) A typical columnar section of the mine strata

which shall:

      (a) Show the name and the thickness of the coalbed

to be mined and any persistent partings;

      (b) Identify the type and show the thickness of

each stratum up to and including the main roof above the coalbed and for

distance of at least ten (10) feet below the coalbed; and

      (c) Indicate the maximum cover over the area to be

mined.

      (5) A description and drawings of the sequence of

installation and spacing of supports for each method of mining used;

      (6) If an automated temporary roof support system

is used, the maximum distance that an automated temporary roof support system

is to be set beyond the last row of permanent support;

      (7) If tunnel liners or arches are to be used for

roof support, specifications and installation procedures for the liners or

arches;

      (8) Drawings indicating the planned width of

openings, size of pillars, method of pillar recovery, and the sequence of mining

pillars;

      (9) A list of all support material required to be

used in the roof, face and rib control system, including, if roof bolts are to

be installed:

      (a) The length, diameter, grade and type of

anchorage unit to be used;

      (b) The drill hole size to be used; and

      (c) The installed torque or tension range for

tensioned roof bolts.

      (10) When mechanically anchored tensioned roof

bolts are used, the intervals at which test holes shall be drilled;

      (11) A description of the method of protecting

persons:

      (a) From falling material at drift openings; and

      (b) When mining approaches within 150 feet of an

outcrop.

      (12) A drawing submitted with a roof control plan

shall contain a legend explaining all symbols used and shall specify the scale

of the drawing, which shall not be less than five (5) feet to the inch or more

than twenty (20) feet to the inch;

      (13) All roof control plan information, including

drawings, shall be submitted on eight and one half (8.5) by eleven (11) inch

paper, or paper folded to this size; and

      (14) Any other information required by the

commissioner.

 

      Section 17. Roof Control Plan Approval Criteria.

This section sets forth the criteria that shall be considered on a mine-by-mine

basis in the formulation and approval of roof control plans and revisions.

      (1) Roof bolts shall be installed on centers not

exceeding five (5) feet lengthwise and crosswise, except as approved by the

commissioner or his authorized representative.

      (2) When tensioned roof bolts are used as a means

of roof support, the torque or tension range shall be capable of supporting

roof bolt loads of at least fifty (50) percent of either the yield point of the

bolt or anchorage capacity of the strata, whichever is less.

      (3) Any opening that is more than twenty (20) feet

wide shall be supported by a combination of roof bolts and conventional

supports.

      (4) In any opening more than twenty (20) feet wide:

      (a) Posts shall be installed to limit each roadway

to sixteen (16) feet wide, where straight, and eighteen (18) feet wide, where

curved; and

      (b) A row of posts shall be set for each five (5)

feet of space between the roadway posts and the ribs.

      (5) An opening shall not be more than thirty (30)

feet wide.

      (6) If installing roof support using mining

machines with integral roof bolters:

      (a) Before an intersection or pillar split is

started, roof bolts shall be installed on at least five (5) foot centers where

the work is performed;

      (b) Where the roof is supported by only two (2)

roof bolts crosswise, openings shall not be more than sixteen (16) feet wide.

      (7) Pillar recovery.

      (a) During development, any dimension of a pillar

shall be at least twenty (20) feet;

      (b) Pillar splits and lifts shall not be more than

twenty (20) feet wide;

      (c) A breaker post shall be installed on a center

of not more than four (4) feet;

      (d) Roadside-radius (turn) posts, or equivalent

support, shall be installed on not more than four (4) foot centers leading into

each pillar split or lift;

      (e) Before full pillar recovery is started in areas

where roof bolts are used as the only means of roof support and openings are

more than sixteen (16) feet wide, at least one (1) row of posts shall be

installed to limit the roadway width to sixteen (16) feet. These posts shall

be:

      1. Extended from the entrance to the split through

the intersection outby the pillar in which the split or lift is being made; and

      2. Spaced on not more than five (5) foot centers.

      (8) Openings that create an intersection shall be

permanently supported or at least one row of temporary supports shall be

installed on not more than five (5) foot centers across the opening before any

other work or travel is permitted in the intersection.

      (9) In a working section where the mining height is

below thirty (30) inches, an automated temporary roof support system shall be

used to the extent practicable during the installation of roof bolts with roof

bolting machines and continuous-mining machines with integral roof bolters.

      (10) In a mine with a longwall mining system:

      (a) Systematic supplemental support shall be

installed throughout:

      1. The tailgate entry of the first longwall panel

prior to any mining; and

      2. In the proposed tailgate entry of each

subsequent panel in advance of the frontal abutment stresses of the panel being

mined.

      (b) If a ground failure prevents travel out of the

section through the tailgate side of the longwall section, the roof control

plan shall address:

      1. Notification of miners that the travelway is

blocked;

      2. Reinstruction of miners regarding escapeways and

escape procedures in the event of an emergency;

      3. Reinstruction of miners on the availability and

use of self-contained self-rescue devices;

      4. Monitoring and evaluation of the air entering

the longwall section;

      5. Location and effectiveness of the two (2) way

communication system; and

      6. A means of transportation from the section to

the main line.

      (c) The plan provisions addressed by paragraph (b)

of this subsection shall remain in effect until a travelway is reestablished on

the tailgate side of a longwall section.

      (11) A roof control plan that does not conform to

the criteria set out in this section may be approved by the commissioner or his

authorized representative, if the plan provides effective control of the roof,

face, and ribs. The commissioner or his authorized representative may require

additional safety measures in a roof control plan.

 

      Section 18. Evaluation and Revision of Roof Control

Plan. (1) A revision of the roof control plan shall be proposed by the

licensee:

      (a) If conditions indicate that the plan is not

suitable for controlling the roof, face, ribs, or coal or rock bursts; or

      (b) If accident and injury experience at the mine

indicates the plan is inadequate; the accident and injury experience at each

mine shall be reviewed at least every six (6) months.

      (2) An unplanned roof fall, rib fall, and coal or

rock burst that occurs in the active workings shall be plotted on a mine map if

it:

      (a) Is above the anchorage zone where roof bolts

are used;

      (b) Impairs ventilation;

      (c) Impedes passage of persons;

      (d) Causes miners to be withdrawn from the area

affected; or

      (e) Disrupts regular mining activities for more

than one (1) hour.

      (3) The mine map on which roof falls are plotted

shall be available at the mine site for inspection by an authorized

representative of the commissioner and a representative of miners at the mine.

      (4) The roof control plan for each mine shall be

reviewed every six (6) months by an authorized representative of the

commissioner. This review shall take into consideration any falls of the roof,

face and ribs and the adequacy of the support systems used at the time.

 

      Section 19. Incorporation by Reference. (1)

"Standard Specification for Roof and Rock Bolts and Accessories",

(1995 Edition), American Society for Testing and Materials (ASTM), Designation

F 432-95.

      (2) It may be inspected or copied at Kentucky

Department for Natural Resources, Administration Building, 1025 Capital Center

Drive, Suite 201, P.O. Box 2244, Frankfort, Kentucky 40602-2244, Monday through

Friday, 8 a.m. to 4:30 p.m.

      (3) It may be obtained from the American Society

for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103,

(610) 832-9500. (23 Ky.R. 1478; Am. 2185; 2493; eff. 12-11-96; TAm eff.

8-9-2007.)