Article 1. Ground Control
4VAC25-40-2770. Ground support.
A. Upon encountering suspected hazardous geological conditions, the operator shall suspend mining activities in the area until a ground control plan has been approved by the director.
B. Ground support shall be used if the operating experience of the mine, or any particular area of the mine, indicates that it is required. If it is required, support, including timbering, rock bolting, or other methods shall be consistent with the nature of the ground and the mining method used. Also see 4VAC25-40-440.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.1, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2780. Loose ground.
Persons shall be trained in the proper methods of testing for, taking down, and supporting loose ground.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.2, eff. July 19, 1989.
4VAC25-40-2790. Inspection of work area.
Miners shall examine and test, where possible, the back, face, and ribs of their working areas, visually and by sounding, at the beginning of each shift and frequently thereafter. Competent persons shall examine the ground conditions during daily visits to ensure that proper testing and ground control practices are being followed. Loose ground shall be taken down or adequately supported before any other work is done. Ground conditions along haulageways and travelways shall be examined periodically and scaled or supported as necessary.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.3, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998; Volume 25, Issue 20, eff. July 8, 2009.
4VAC25-40-2800. Scaling bar to be provided.
A scaling bar of proper length and design shall be provided where manual scaling may be required. Picks or other short tools shall not be used for scaling when this use places the user in danger from falling material.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.4, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998; Volume 25, Issue 20, eff. July 8, 2009.
4VAC25-40-2810. Timbers to be blocked or wedged.
Timbers used for support of ground in active working areas shall be blocked or wedged tightly. Loosened or dislodged timbers shall be promptly repaired or replaced.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.5, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2820. Installation of ground support in shafts.
When necessary, permanent or temporary ground support shall be installed near enough to the bottom of the shaft during shaft sinking to prevent falls of rocks from the sides of the shaft.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.6, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2830. Shaft pillars.
Shaft pillars shall have sufficient strength to protect operating shafts.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.7, eff. July 19, 1989.
4VAC25-40-2840. Rock-bolt installations.
Rock-bolt installations, where needed, shall be installed in a manner to provide safe and effective ground support as soon as possible after an area is exposed.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.8, eff. July 19, 1989.
4VAC25-40-2850. Acceptable rock-bolting materials.
Only rock-bolting materials acceptable to the MSHA or other approved agency shall be used.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.9, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2860. Rock-bolt hole drill bits.
Rock-bolt hole drill bits shall be easily identifiable by sight or feel and diameters shall be within a tolerance of 0.030 inches of the manufacturer's recommended hole diameter for the anchor used.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.10, eff. July 19, 1989.
4VAC25-40-2870. Rock-bolt torque tests.
Rock bolts used as a means of ground support and which require torquing shall be torqued to a value within the range determined from information obtained by tests in the strata in which the rock-bolt assembly is used. In no case shall the applied torque cause a bolt tension that would exceed the yield point or anchorage capacity of the rock-bolt assembly being used.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.11, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2880. Rock-bolt anchorage tests.
When rock bolts are used as a means of ground support, anchorage test procedures shall be established and tests shall be conducted to determine the anchorage capacity of rock-bolt installations. The results shall be in writing and made available to the director or his duly authorized representative.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.12, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-2890. Torque test requirements.
When installing point-anchor rock bolts:
1. A torque test shall be conducted on at least every fourth installed bolt;
2. Torque testing shall be conducted immediately after bolt installation;
3. If the recommended torque has not been achieved, the equipment used to install the bolt shall be adjusted and the next bolt installed shall then be tested; and
4. If the recommended torque has not been achieved on the majority of bolts installed in a working place through equipment adjustment, supplemental support equivalent to longer roof bolts with adequate anchorage, steel or wood sets, or cribs shall be installed.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.13, eff. July 19, 1989.