When do need shoring and egresses when trencing

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# Occupational Safety and Health Administration (cont.) ## 1926.651(b)(3). (cont.) 1926.651(c)(1)(v) Structural ramps used in lieu of steps shall be provided with cleats or other surface treatments on the top surface to prevent slipping. ## 1926.651(c)(2). Means of egress from trench excavations. A stairway, ladder, ramp or other safe means of egress shall be located in trench excavations that are 4 feet (1.22 m) or more in depth so as to require no more than 25 feet (7.62 m) of lateral travel for employees. ## 1926.651(d) Exposure to vehicular traffic. Employees exposed to public vehicular traffic shall be provided with, and shall wear, warning vests or other suitable garments marked with or made of reflectorized or high-visibility material. ## 1926.651(e) Exposure to falling loads. No employee shall be permitted underneath loads handled by lifting or digging equipment. Employees shall be required to stand away from any vehicle being loaded or unloaded to avoid being struck by any spillage or falling materials. Operators may remain in the cabs of vehicles being loaded or unloaded when the vehicles are equipped, in accordance with $1926.601(b)(6), to provide adequate protection for the operator during loading and unloading operations. Submit Feedback ## 1926.651(f) Warning system for mobile equipment. When mobile equipment is operated adjacent to an excavation, or when such equipment is required to approach the edge of an excavation, and the operator does not have a clear and direct view of the edge of the excavation, a warning system shall be utilized such as barricades, hand or mechanical signals, or stop logs. If possible, the grade should be away from the excavation. ## 1926.651(g) Hazardous atmospheres- 1926.651(g)(1) Testing and controls. In addition to the requirements set forth in subparts D and E of this part (29 CFR 1926.50 - 1926.107) to prevent exposure to harmful levels of atmospheric contaminants

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SAMPLE-Excavation Checklist # EXCAVATION CHECKLIST (To be completed by a Competent Person) SITE LOCATION: <empty> DATE: <empty> TIME: <empty> COMPETENT PERSON: <empty> SOIL TYPE (See attached form): <empty> SOIL CLASSIFICATION: <empty> EXCAVATION DEPTH: <empty> EXCAVATION WIDTH: <empty> TYPE OF PROTECTIVE SYSTEM USED: <empty> ## Indicate for each item: YES - NO - or N/A for not applicable <table><tr><th>1. General Inspection of Jobsite:</th><th></th></tr><tr><td>A. Excavations, adjacent areas, and protective systems inspected by a competent person daily before the start of work.</td><td></td></tr><tr><td>B. Competent person has the authority to remove employees from the excavation immediately.</td><td></td></tr><tr><td>C. Surface encumbrances removed or supported.</td><td></td></tr><tr><td>D. Employees protected from loose rock or soil that could pose a hazard by falling or rolling into the excavation.</td><td></td></tr><tr><td>E. Hard hats worn by all employees.</td><td></td></tr><tr><td>F. Spoils, materials, and equipment set back at least two feet from the edge of the excavation.</td><td></td></tr><tr><td>G. Barriers provided at all remotely located excavations, wells, pits, shafts, etc.</td><td></td></tr><tr><td>H. Walkways and bridges over excavations four feet or more in depth are equipped with standard guardrails and toeboards.</td><td></td></tr><tr><td>I. Warning vests or other highly visible clothing provided and worn by all employees exposed to public vehicular traffic.</td><td></td></tr><tr><td>J. Employees required to stand away from vehicles being loaded or unloaded.</td><td></td></tr><tr><td>K. Warning system established and utilized when mobile equipment is operating near the edge of the excavation.</td><td></td></tr><tr><td>L. Employees prohibited from going under suspended loads.</td><td></td></tr><tr><td>M. Employees prohibited from working on the faces of slopes or benched excavations above other employees.</td><td></td></tr><tr><td>2. Uti…

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# EXCAVATION CHECKLIST (To be completed by a Competent Person) (cont.) ## Indicate for each item: YES - NO - or N/A for not applicable (cont.) <table><tr><th>D. Structural ramps used for equipment designed by a registered professional engineer (RPE).</th><th></th></tr><tr><td>E. Ramps constructed of materials of uniform thickness, cleated together on the bottom, equipped with no-slip surface.</td><td></td></tr><tr><td>F. Employees protected from cave-ins when entering or exiting the excavation.</td><td></td></tr><tr><td>4. Wet Conditions:</td><td></td></tr><tr><td>A. Precautions take to protect employees from the accumulation of water.</td><td></td></tr><tr><td>B. Water removal equipment monitored by a competent person.</td><td></td></tr><tr><td>C. Surface water or runoff diverted or controlled to prevent accumulation in the excavation.</td><td></td></tr><tr><td>D. Inspections made after every rainstorm or other hazard-increasing occurrence.</td><td></td></tr><tr><td>5. Hazardous Atmosphere:</td><td></td></tr><tr><td>A. Atmosphere within the excavation tested where there is a reasonable possibility of an oxygen deficiency, combustible or other harmful contaminant exposing employees to a hazard. B. Adequate precautions taken to protect employees from exposure to an atmosphere containing less than 19.5% oxygen and/or to other hazardous atmospheres.</td><td></td></tr><tr><td>C. Ventilation provided to prevent employee exposure to an atmosphere containing flammable gas in excess of 10% of the lower explosive limit of the gas.</td><td></td></tr><tr><td>D. Testing conducted often to ensure that the atmosphere remains safe. E. Emergency equipment, such as breathing apparatus, safety harness and lifeline, and/or basket stretcher readily available where hazardous atmospheres could or do exist.</td><td></td></tr><tr><td>F. Employees trained to use personal protective and other rescue equipment.</td><td></td></tr><tr><td>G. Safety harness and lifeline used and individually a…

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# Trenching and Excavation (cont.) ## Housekeeping (cont.) - Excavated material, pipes etc. are placed 1 metre away from the edge of the excavation or trench wall? - Are pumps available to remove water? - Is the base and foot of the ladder secure, and free of garbage or water? - Are materials placed on the site obstructing the worker's or vehicle's ability to move freely? - Are established traffic controls used, where required, including adequate signage, personnel, and lighting? - Has the excavation been marked to make the workers and others aware of the excavation (e.g., fence, flags, or other safeguards)? - Are sanitary facilities available at the site, as appropriate? ## General - Are proper barriers or guardrails in place to protect anyone or equipment falling into the excavation or trench? - Has the air in the excavation been tested for low oxygen, and hazardous gasses and vapours? - Is a safe means of entry and exit provided such as a sufficiently long and secured ladder placed at appropriate distances (within 25 feet of all workers)? - Are cracks visible in the ground around the trench or excavation that may indicate soil movement? - Are there any signs of water seeping into the trench or excavation? - Are workers wearing appropriate PPE (e.g., hard hats, respirators, , safety boots, hearing protection)? - Are high visibility vests or clothing provided and worn by all exposed to vehicular traffic? - Is first aid equipment available at the site? - Are operators qualified to operate the heavy machinery or equipment? - Does a competent person regularly inspect the excavation (at the start of each shift before work begins or after any event likely to have affected the strength or stability of the excavation)? - Is there a competent person stationed at the surface of the trench to warn workers in the trench of danger and to provide emergency help? - Is the trench a confined space, and are the requirements of the confined space program met?…

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# Requirements for Protective Systems {Division 3/Subdivision P 29 CFR 1926.652} (cont.) ## Selection of Protective Systems (cont.) This material is for training use only # Protective Systems [29 CFR 1926.652(a)] Excavations and trenches less than five feet deep must still be sloped, benched, or otherwise supported when a Competent Person determines there is indication of cave-in. a Be careful not to get caught up on just the five foot depth requirement. Consider work practices in a shallow trench as well (i.e. working hunched over or on hands and knees). ## Selection of Protective Systems Protective systems are divided into two categories and include four choices in each: 1. Sloping and benching systems; and 2. ...everything else. The basic systems for protecting employees from cave-ins are sloping, benching, shoring, and shielding. The system that you should use depends on factors such as soil type and water content, excavation depth and width, the nature of the work, and nearby activities that could increase the risk of a cave-in. The competent person has the responsibility for considering these factors and for determining the appropriate protective system. A registered professional engineer must design protective systems for all excavations that are more than 20 feet deep. (from OR-OSHA's publication titled, “Excavations” Pub. #440-2174 (6/06)). OR-OSHA 302 Excavation Safety 24

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# General Requirements {Division 3/Subdivision P 29 CFR 1926.651} (cont.) ## Stability of Adjacent Structures [29 CFR 1926.651 (i)] (cont.) This material is for training use only # Water Accumulation [29 CFR 1926.651(h)] Water is one of the major concerns during excavation operations. Water simply allows dirt to move much easier and quicker than it would normally. Think of digging in the sand on a beach. Capillary effect - standing water “wicks” up and saturates the trench sidewalls as it "wicks" up the earth's natural at-rest angle. Think of this "wicking" effect like a bath towel draped over a bathtub with standing water or the wick on a candle. Type C soil provides a shorter wicking effect than a more cohesive, Type A soil (with a significant amount of clay). Water (i.e. rain) can also fill tension and surface cracks at the edge of the trench causing a hydrostatic effect within this ‘tube' leading to wedge failure. Slough off ## Stability of Adjacent Structures [29 CFR 1926.651(i)] Support systems such as shoring, bracing, underpinning, screw retention systems, or other engineering must be provided to ensure stability. Don't forget Sidewalks and other pavements. OR-OSHA 302 Excavation Safety 14

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# Hazardous Atmospheres [29 CFR 1926.651(g)] (cont.) ## Testing and Controls (cont.) This material is for training use only # General Requirements {Division 3/Subdivision P 29 CFR 1926.651} ## Water Accumulation [29 CFR 1926.651(h)] Employees must be properly protected when working in excavations where water has accumulated or is accumulating. Precautions will vary with each situation but may include diversion, dewatering (well pointing) systems, special supporting systems, or water removal equipment. The competent person must monitor water removal equipment. Water is one of the major concerns during excavation operations. The action of water in excavations can cause undermining and cave-ins. ## Stability of Adjacent Structures [29 CFR 1926.651 (i)] Where the stability of adjacent buildings, walls, or other structures is endangered by excavation operations, support systems such as shoring, bracing, or underpinning must be provided to ensure stability. Excavation below the level of the base or footing that could pose a hazard is not permitted except when: • the excavation is in stable rock, or • support system (underpinning) is provided, or - Registered Professional Engineer approves. Sidewalks, pavements, and appurtenant structure must not be undermined unless a support system or another method of protection is provided to protect employees from collapse. OR-OSHA 302 Excavation Safety 13

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# Trenching and Excavation (cont.) ## What factors determine what is the appropriate protective system to use? (cont.) - Water content of soil - Changes due to weather or climate - Surcharge loads (e.g., spoil, other materials to be used in the trench) and - Other operations in the area Always check the legislative requirements in your jurisdiction related to the use of protective systems. ## What are the different types of protective systems used to protect against cave-ins? There are two basic methods of protecting workers against cave-ins: - Sloping - Temporary protective structures (e.g., shoring, trench boxes, pre-fabricated systems, hydraulic systems, engineering systems, etc.) ## Sloping Sloping involves cutting back the trench wall at an angle that is inclined away from the work area of the excavation. The angle of slope required depends on the soil conditions. Benching is a similar method to sloping. ## Temporary protective structure WorkSafe Saskatchewan defines a temporary protective structure as "a structure or device in an excavation, trench, tunnel or excavated shaft that is designed to provide protection from cave-ins, collapse, sliding or rolling materials, and includes shoring, trench boxes, trench shields and similar structures." Shoring is a system that supports the sides or walls. Shoring requires installing aluminum, steel, or wood panels that are supported by screws or hydraulic jacks. Some systems can be installed without the workers entering the trench. This option provides additional safety for those workers. Wherever possible, install the shoring equipment as the excavation proceeds. If there is any delay between digging and shoring, no one should enter the unprotected trench. Trenching and Excavation CCOHS

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# Occupational Safety and Health Administration (cont.) ## 1926.651(g)(2).(i) (cont.) Employees entering bell-bottom pier holes, or other similar deep and confined footing excavations, shall wear a harness with a life-line securely attached to it. The lifeline shall be separate from any line used to handle materials, and shall be individually attended at all times while the employee wearing the lifeline is in the excavation. ## 1926.651(h) Protection from hazards associated with water accumulation. ## 1926.651(h)(1) Employees shall not work in excavations in which there is accumulated water, or in excavations in which water is accumulating, unless adequate precautions have been taken to protect employees against the hazards posed by water accumulation. The precautions necessary to protect employees adequately vary with each situation, but could include special support or shield systems to protect from cave-ins, water removal to control the level of accumulating water, or use of a safety harness and lifeline. - 1926.651(h)(2) If water is controlled or prevented from accumulating by the use of water removal equipment, the water removal equipment and operations shall be monitored by a competent person to ensure proper operation. - 1926.651(h)(3) If excavation work interrupts the natural drainage of surface water (such as streams), diversion ditches, dikes, or other suitable means shall be used to prevent surface water from entering the excavation and to provide adequate drainage of the area adjacent to the excavation. Excavations subject to runoff from heavy rains will require an inspection by a competent person and compliance with paragraphs (h)(1) and (h)(2) of this section. - 1926.651(i) Stability of adjacent structures. ## 1926.651(i)(1) Where the stability of adjoining buildings, walls, or other structures is endangered by excavation operations, support systems such as shoring, bracing, or underpinning shall be provided to ensure the stability of suc…

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# Trenching and Excavation (cont.) ## What should occur before beginning an excavation? (cont.) - Check areas near the site for potential hazards and sources that can impact the stability of the soil. Be aware that nearby vehicles and equipment can cause the soil to vibrate and then collapse. - Determine if nearby buildings or structures and their foundations may put pressure on the soil and affect the walls of the trench. - Test for hazardous gas, vapours, and dust before entering. Test for oxygen levels in the space before entering, and during the work as required. - Plan appropriate organization of the work site, and good housekeeping practices including moving debris and excavated soil far enough away from the excavation site. - Remove water from the excavation. - Protect workers from falling into the excavation. - Identify appropriate personal protective equipment including high visibility apparel for vehicular traffic and make sure every worker wears them as required. - Have a worker above ground when a worker is working in the trench to warn those in the trench of danger and to provide emergency help. - Determine if the trench is considered a confined space If so, do not allow workers to enter the trench until the requirements of the organization's confined space program are met, including entry permits and training. - Prepare work permits for work in confined spaces, as appropriate. - Have a means of exit provided from the inside of the trench, usually no more than 8m (25 ft) away from any worker in the trench. - Plan for adverse weather conditions (e.g. hot or cold environments, storms, etc.). - Prepare an emergency plan and rescue procedures. - Keep first aid equipment at the site. - Educate and train workers about all existing and potential hazards and risks and appropriate safety measures. ## What factors determine what is the appropriate protective system to use? In general, trenches that are 1.2 metres (4 feet) deep or great…