W. Va. Code R. § 36-23-36

Current through Register Vol. XLI, No. 24, June 14, 2024

Section 36-23-36 - Excavations, Trenching, and Shoring

36.1. General protection requirements.

(a) Walkways, runways, and sidewalks shall be kept clear of excavated material or other obstructions and no sidewalks shall be undermined unless shored to carry a minimum live load of one hundred and twenty-five (125) pounds per square foot.

(b) If planks are used for raised walkways, runways, or sidewalks, they shall be laid parallel to the length of the walk and fastened together against displacement.

(c) Planks shall be uniform in thick­ness and all exposed ends shall be provided with beveled cleats to prevent tripping.

(d) Raised walkways, runways, and sidewalks shall be provided with plank steps on strong stringers. Ramps, used in lieu of steps, shall be provided with cleats to insure a safe walking surface.

(e) All employees shall be provided with and protected with personal protective equipment for the protection of the head, eyes, respiratory organs, hands, feet and other parts of the body.

(f) Employees exposed to vehicular traffic shall be provided with and shall be instructed to wear warning vests marked with or made of reflectorized or high visibility material.

(g) Employees subjected to hazardous dusts, gases, fumes, mists, or atmospheres deficient in oxygen, shall be provided with and protected with approved respiratory protec­tion.

(h) No person shall be permitted under loads handled by power shovels, der­ricks, or hoists. to avoid any spillage employ­ees shall be required to stand away from any vehicle being loaded.

(i) Daily inspections of excavations shall be made at the beginning of and periodi­cally during each shift by a certified and competent person. If evidence of possible cave-ins or slides is apparent, all work in the excavation shall cease until the necessary precautions have been taken to safeguard the employees.

36.2. Specific excavation requirements.

(a) Prior to opening and excavation, effort shall be made to determine whether underground installations; i.e., sewer, tele­phone, water, fuel, electric lines, etc., will be encountered, and if so, where such under­ground installations are located. When the excavation approaches the estimated location of such an installa­tion, the exact location shall be determined and when it is uncovered, proper supports shall be provided for the existing installation. Utility companies shall be contacted and advised of proposed work prior to the start of actual excavation.

(b) Trees, boulders, and other surface encumbrances, located so as to create a hazard to employees involved in excavation work or in the vicinity thereof at any time during opera­tions, shall be removed or made safe before excavating is begun.

(c) The walls and faces of all excava­tions in which employees are exposed to dan­ger from moving ground shall be guarded by a shoring system, sloping of the ground, or some other equivalent means.

(d) Excavations shall be inspected by a competent and certified person after every rainstorm or other hazard-increasing occur­rence, and the protection against slides and cave-ins shall be increased if necessary.

(e) The determination of the angle of repose and design of the supporting system shall be based on careful evaluation of perti­nent factors such as :

Depth or cut; anticipated changes in materials from exposure to air, sun, water, or freezing; loading imposed by structures, equipment, overlying material, or stored mate­rial; and vibration from equipment, blasting, traffic, or other sources.

(f) supporting systems; i.e., piling, cribbing, shoring, etc., shall be designed by a qualified person and meet accepted engineer­ing requirements. When tie rods are used to restrain the top of the sheeting or other retain­ing systems, the rods shall be securely an­chored well back of the angle of repose. When tight sheeting or sheet piling is used, full loading due to groundwater table shall be assumed, unless prevented by weep holes or drains or other means. Additional stringers, ties, and bracing shall be provided to allow for any necessary temporary removal of individual supports.

(g) All slopes shall be excavated to at least the angle of repose except for areas where solid rock allows for line drilling or presplit­ting.

(h) the angle of repose shall be flat­tened when an excavation has water condi­tions, silty materials, loose boulders, and areas where erosion, deep frost action, and slide planes appear.

(i)

(1) In excavations which employ­ees may be required to enter, excavated or other material shall effectively be stored and retained at least two (2) feet or more from the edge of the excavation.

(2) As an alternative to the clearance prescribed in subparagraph (1) of this paragraph, the employer may use effective barriers or other retaining devices in lieu thereof in order to prevent excavated or other materials from falling into the excavation.

(j) Sides, slopes, and faces of all excavations shall meet accepted engineering requirements by scaling, benching, barricad­ing, rock bolting, wire meshing, or other equally effective means. Special attention shall be given to slopes which may be adversely affected by weather or moisture content.

(k) Support systems shall be planned and designed by a qualified person when excavation is in excess of twenty (20) feet in depth, adjacent to structures or improvements, or subject to vibration or ground water.

(l) Materials used for sheeting, sheet piling, cribbing, bracing, shoring, and under­pinning shall be in good serviceable condition, and timbers shall be sound, free from large or loose knots, and of proper dimensions.

(m) Special precautions shall be taken in sloping or shoring the sides of excavations adjacent to a previously back-filled excavation or a fill, particularly when the separation is less than the depth of the excavation. Particu­lar attention also shall be paid to joints and seams of material comprising a face and the slope of such seams and joints.

(n) Except in hard rock, excavations below the level of the base of footing of any foundation or retaining wall shall not be per­mitted, unless the wall is underpinned and all other precautions taken to insure the stability of the adjacent walls for the protection of employees involved in excavation work or in the vicinity thereof.

(o) If the stability of adjoining build­ings or walls is endangered by excavations, shoring, bracing, or underpinning shall be provided as necessary to insure their safety. Such shoring, bracing, or underpinning shall be inspected daily or more often, as conditions warrant, by a competent person and the pro­tection effectively maintained.

(p) Diversion ditches, dikes, or other suitable means shall be used to prevent surface water from entering an excavation and to provide adequate drainage of the area adjacent to the excavation. Water shall not be allowed to accumulate in an excavation.

(q) It is necessary to place or operate power shovels, derricks, trucks, materials, or other heavy objects on a level above and near an excavation, the side of the excavation shall be sheet-piled, shored, and braced as necessary to resist the extra pressure due to such super­imposed loads.

(r) Blasting and the use of explosives shall be performed in accordance with these rules and regulations.

(s) When mobile equipment is utilized or allowed adjacent to excavations, substantial stop logs or barricades shall be in­stalled. If possible, the grade should be away from the excava­tion.

(t) Adequate barrier physical protec­tion shall be provided at all remotely located excavations. All wells, pits, shafts, etc., shall be barricaded or covered. Upon completion of exploration and similar operations, tempo­rary wells, pits, shafts, etc., shall be back-­filled.

(u) If possible, dust conditions shall be kept to a minimum by the use of water, salt, calcium chloride, oil, or other means.

(v) In locations where oxygen defi­ciency or gaseous condi­tions are possible, air in the excavation shall be tested, immediately prior to working entering such area; at least every two (2) hours and as often as necessary to protect the safety of the workers. Controls, as set forth in these regulations, shall be estab­lished to assure acceptable atmospheric condi­tions.

When flammable gases are present, adequate ventilation shall be provided or sources of ignition shall be eliminated. Attended emer­gency rescue equipment, such as breathing apparatus, a safety harness and line, basket stretcher, etc., shall be readily available where adverse atmospheric conditions may exist or develop in an excavation.

(w) Where employees or equipment are required or permitted to cross over exca­vations, walkways or bridges with standard guardrails shall be provided.

(x) Where ramps are used for employ­ees or equipment, they shall be designed and constructed by qualified persons in accor­dance with accepted engineering requirements.

(y) All ladders used on excavation operations shall be in accordance with the requirements of these regulations.

36.3. Specific trenching requirements.

(a) Banks more than five (5) feet high shall be shored, laid back to a stable slope, or some other equivalent means of protec­tion shall be provided where employees may be exposed to moving ground or cave-ins. Refer to Table 47 as a guide in sloping of banks. Trenches less than five (5) feet in depth shall also be effectively protected when examination of the ground indicates hazardous ground movement may be expected.

(b) Sides of trenches is unstable or soft material, five (5) feet or more in depth, shall be shored, sheeted, braced, sloped, or otherwise supported by means of sufficient strength to protect the employees working within them. See Tables 47 and 48.

(c) Sides of trenches in hard or com­pact soil, including embankments,

shall be shored or otherwise supported when the trench is more than five (5) feet in depth and eight (8) feet or more in length. In lieu of shoring, the sides of the trench above the five (5) foot level may be sloped to preclude col­lapse, but shall not be steeper than a one (1) foot rise to each one-half (1/2) foot horizontal. When the outside diameter of a pipe is greater than six (6) feet, a bench of four (4) foot minimum shall be provided at the toe of the sloped portion.

(d) Materials used for sheeting and sheet piling, bracing, shoring, and underpin­ning, shall be in good serviceable condition, and timbers used shall be sound and free from large or loose knots, and shall be designed and installed so as to be effective to the bottom of the excavation.

(e) Additional precautions by way of shoring and bracing shall be taken to prevent slides or caveins when excavations or trenches are made in locations adjacent to backfilled excavations, or where excavations are subject­ed to vibrations from railroad or highway traffic, the operation of machinery, or any other source.

(f) Employees entering bell-bottom pier holes shall be protected by the installation of a removable-type casing of sufficient strength to resist shifting of the surrounding earth. Such temporary protection shall be provided for the full depth of that part of each pier hole which is above the bell. A lifeline, suitable for instant rescue and securely fas­tened to a shoulder harness, shall be worn by each employee entering the shafts. This life­line shall be individually manned and separate from any line used to remove materials exca­vated from the bell footing.

(g)

(1) Minimum requirements for trench timbering shall be in accordance with Table 48.

(2) Braces and diagonal shores in a wood shoring system shall not be subjected to compressive stress in excess of values given by the following formula:

S = 1300 - 20L/D

Maximum ratio L/D = 50

Where:

L = Length, unsupported, in inches

D = Least side of the timber,

in inches

S = Allowable stress in pounds per square inch of cross-section

(h) When employees are required to be in trenches four (4) feet deep or more, an adequate means of exit, such as a ladder or steps, shall be provided and located so as to require no more than twenty-five (25) feet of lateral travel.

(i) Bracing or shoring of trenches shall be carried along with the excavation.

(j) Cross braces or trench jacks shall be placed in true horizontal position, be spaced vertically, and be secured to prevent sliding, falling, or kickouts.

(k) Portable trench boxes or sliding trench shield may be used for the protection of personnel in lieu of a shoring system or slop­ing. Where such trench boxes or shields are used, they shall be designed, constructed, and maintained in a manner which will provide protection equal to or greater than the sheeting or shoring required for the trench.

(l) Backfilling and removal of trench supports shall progress together from the bottom of the trench. Jacks or braces shall be released slowly and, in unstable soil, ropes shall be used to pull out the jacks or braces from above after employees have cleared the trench.

36.4. Definitions applicable to this sub­section.

(a) "Accepted Engineering Require­ments (or Practice)" Those requirements or practices which are compatible with standards required by a registered architect, a registered professional engineer, or other duly licensed or recognized authority.

(b) "Angle of Repose" the greatest angle above the horizontal plane at which a material will lie without sliding.

(c) "Bank" A mass of soil rising above a digging level.

(d) "Belled Excavation" A part of a shaft or footing excavation, usually near the bottom and bell-shaped; i.d., an enlargement of the cross section above.

(e) "Braces (Trench)" The horizontal members of the shoring system whose ends bear against the uprights or stringers.

(f) "Excavation" Any manmade cavity or depression in the earth's surface, including its sides, walls, or faces, formed by earth removal and producing unsupported earth conditions by reasons of the excavation. If installed forms or similar structures reduce the depth-to-width relationship, an excavation may become a trench.

(g) "Faces" See paragraph (k) of this section.

(h) "hard compact Soil" All earth materials not classified as running or unstable.

(i) "Kickouts" Accidental release or failure of a shore or brace.

(j) "Sheet Pile" A pile, or sheeting, that may form one (1) of a continuous inter­locking line, or a row of timber, concrete, or steel piles, driven in close contact to provide a tight wall to resist the lateral pressure of water, adjacent earth, or other materials.

(k) "sides," "Walls," or "Faces" The vertical or inclined earth surfaces formed as a result of excavation work.

(l) "Slope" The angle with the hori­zontal at which a particular earth material will stand indefinitely without movement.

(m) "Stringers (Wales)" the horizontal members of a shoring system whose sides beat against the uprights or earth.

(n) "Trench" A narrow excavation made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench is not greater than fifteen (15) feet.

(o) "Trench Jack" Screw or hydraulic type jacks used as cross bracing in a trench shoring system.

(p) "Trench Shield" A shoring system composed of steel plates and bracing, welded or bolted together, which support the walls of a trench from the ground level to the trench bottom and which can be moved along as work progresses.

(q) "Unstable Soil" Earth material, other than running, that because of its nature or the influence of related conditions, cannot be depended upon to remain in place without extra support, such as would be furnished by a system of shoring.

(r) "Uprights" The vertical members of a shoring system.

(s) "Wales" See paragraph (m) of this section.

(t) "Walls" See paragraph (k) of this section.

W. Va. Code R. § 36-23-36