Trenches 5 feet (1.5 meters) deep or greater require a protective system unless the excavation is made entirely in stable rock. Trench protective systems include which of the following. Although sloping and benching is a good method for excavations, there are still some problems you may encounter. Management can use analytics to view safety trends by personnel, team, project, or organization. Maximum allowable slope means the steepest incline of an excavation face that is acceptable for the most favorable site conditions as protection against cave-ins, and is expressed as the ratio of horizontal distance to vertical rise (H:V). The identity of the registered professional engineer approving the design. ). Sloping involves cutting back the trench wall at an angle that is inclined away from the work area of the excavation. Installation of a support system shall be closely coordinated with the excavation of trenches. (Click the Appendix B button below to see the Maximum Allowable Slope chart. Angles have been rounded off. If the number is prime, write prime. After that time the data may be stored off the jobsite, but a copy of the data shall be made available to the Secretary upon request. using the attachments and the video link about to answer the questions below. Timber, aluminum, or other suitable material may be used in the construction. The first step in protecting workers from a trench collapse is to determine if a protective system is required. After that time this data may be stored off the jobsite, but a copy shall be made available to the Secretary upon request. The flatter the angle, the more protection the sloping offers. means the separation of a mass of soil or rock material from the side of an excavation, or the loss of soil from under a trench shield or support system, and its sudden movement into the excavation, either by falling or sliding, in sufficient quantity so that it could entrap, bury, or other wise injure and immobilize a person. OSHA standards mandate that all excavations _____ be protected against collapse. Removal shall begin at, and progress from, the bottom of the excavation. 1926.652 (b) Design of sloping and benching systems. Distress is evidenced by such phenomena as the development of fissures in the face of or adjacent to an open excavation; the subsidence of the edge of an excavation; the slumping of material from the face or the bulging or heaving of material from the bottom of an excavation; the spalling of material from the face of an excavation; and ravelling, i.e., small amounts of material such as pebbles or little clumps of material suddenly separating from the face of an excavation and trickling or rolling down into the excavation. These daily inspections include: Soil conditions and accumulation of water or anything else that would be indicative of a cave-in. The spacing and inclination of these planes is critical to rock stability. Maximum allowable slope. With an average of 19 trench fatalities per year, protective systems are essential for trench safety. in Pearland. (ii)Excavations are less than 5 feet (1.52m) in depth and examination of the ground by a competent person provides no indication of a potential cave-in. Excavation of material to a level no greater than 2 feet (.61 m) below the bottom of the members of a support system shall be permitted, but only if the system is designed to resist the forces calculated for the full depth of the trench, and there are no indications while the trench is open of a possible loss of soil from behind or below the bottom of the support system. It should be installed with aluminum hydraulic supports or other types of supports to prevent digging, soil movement and subsidence. the safe angle must be more gradual when an excavation: The example in the image to the right shows the sloping requirements for Type C soil. Protective systems include support systems, sloping and benching systems, shield systems, and other systems that provide the necessary protection. That is, for every foot of depth, the trench must be excavated back 1 feet, resulting in a maximum angle of 34 degrees. Please enable JavaScript on your browser and try again. At the time of the collapse, a backhoe was still extracting soil from the trench. The width, depth and length will impact the size of the protective system you need. (3) Information explaining the use of the tabular data is presented in paragraph (e) of this appendix. Human and administrative resources. Employees shall be protected from the hazard of cave-ins when entering or exiting the areas protected by shields. Protective systems for trench safety include sloping, shoring, shielding, and benching. The four types of protective systems for trenching and excavation are: Benching Sloping Shoring Shielding Read below for more information on each protective measure Benching Excavation Safety (i) Shield systems shall not be subjected to loads exceeding those which the system was designed to withstand. After that time the design need not be at the jobsite, but a copy shall be made available to the Secretary upon request. After that time the data may be stored off the jobsite, but a copy of the data shall be made available to the Secretary upon request. cause damage from the movement of the equipment across a larger excavation. There are four types of protective systems used for trench safety: sloping, shoring, shielding, and benching. Trench protective systems include which of the following. Click on the buttons to see 1926.652(c) requirements, Appendix C and D requirements, and a video on sloping and shoring. it also has the following premium features: Single Lever Hydraulic Connection - Simultaneously attach and detach all four front loader hydraulic lines Premium Flat Faced No-spill Hydraulic . means a structure such as underpinning, bracing, or shoring, which provides support to an adjacent structure, underground installation, or the sides of an excavation. (b) Soil Classification. Ramp (ii) Slopes specified in paragraph (b)(1)(i) of this section, shall be excavated to form configurations that are in accordance with the slopes shown for Type C soil in appendix B to this subpart. Deviation from the specifications, recommendations, and limitations issued or made by the manufacturer shall only be allowed after the manufacturer issues specific written approval. Sloping. Designs shall be in written form and shall include at least the following: The magnitude of the slopes that were determined to be safe for the particular project; The configurations that were determined to be safe for the particular project; and. OSHA identifies three basic types of protective systems: shielding (devices designed to protect workers in the event of a collapse, such as trench boxes); shoring (bracing designed to prevent collapse, such as hydraulic shoring or slide-rail systems); and sloping or benching trench walls away from the trench bottom at However, in this case, a competent person must examine the ground and find no indication of a potential cave-in. However, a professional engineer, registered in any state is deemed to be a "registered professional engineer" within the meaning of this standard when approving designs for "manufactured protective systems" or "tabulated data" to be used in interstate commerce. Features include: A smooth and comfortable ride. Limits compaction. High traction characteristics are ideal for loader applications. . Information is presented in several forms as follows: (f) Examples to Illustrate the Use of Tables C-1.1 through C-1.3. What are the OSHA Trenching and Excavation Standards? Shores of this type are generally used in a water system, as an assist to timber shoring systems, and in shallow trenches where face stability is required. Hydraulic Shoring. A shoring system is a structure such as a metal hydraulic, mechanical or timber shoring system that supports the sides of an excavation and which is designed to prevent caveins. Designs shall be in written form and shall include the following: A plan indicating the sizes, types, and configurations of the materials to be used in the protective system; and. All shoring should be installed from the top down and removed from the bottom up. They have an emergency fund that is 6% of their monthly budget and they have a savings of 7% per month. means a method of protecting employees from cave-ins, from material that could fall or roll from an excavation face or into an excavation, or from the collapse of adjacent structures. As the term indicates, underpinning is a procedure in which the foundation is physically reinforced. In Type B soil, the trench excavation is permitted only in cohesive soil. If a trench work site needs worker protection and active shoring, contractors should use a system that applies a load to the trench wall greater than the earthen load coming from the trench wall. Occupational Safety and Health Administration, Outreach Training Program (10- and 30-hour Cards), OSHA Training Institute Education Centers, Severe Storm and Flood Recovery Assistance. OSHA excavation standards are specifications of requirements for trenching and excavation, including protective systems. Footnote(2) A short-term maximum allowable slope of 1/2H:1V (63) is allowed in excavations in Type A soil that are 12 feet (3.67 m) or less in depth. Employees shall not be allowed in shields when shields are being installed, removed, or moved vertically. (1) Option (1)-Allowable configurations and slopes. When installing shoring be sure to always use engineered shoring materials for the cave in protection. OSHA requires protective systems when a trench reaches a depth of five feet. Their net monthly income is $4,500. Timber shoring systems are very versatile since they are custom built to fit the trench. (ii) Shields shall be installed in a manner to restrict lateral or other hazardous movement of the shield in the event of the application of sudden lateral loads. As the trench is backfilled, the braces and planks can be removed to be used at another site. (External link). At least one copy of the design shall be maintained at the jobsite during construction of the protective system. Benching systems cannot be installed in type C soil. mean the horizontal members of a shoring system installed perpendicular to the sides of the excavation, the ends of which bear against either uprights or wales, means any man-made cut, cavity, trench, or depression in an earth surface, formed by earth removal. Workers must monitor activity going on around the area of excavation for hazards as well. OSHA has cited KCC Group Inc., Pearland, Texas, and proposed penalties totaling $133,000 for failing to protect workers from trenching hazards that led to an employee's death. After that time, the design may be stored off the jobsite, but a copy of the design shall be made available to the Secretary upon request. Rezervni dijelovi; Autolimarija i autolakirnica; Autoelektrika Please answer all of the questions before checking your quiz answers. A safety and health program is called a living document why. Pneumatic Shoring. The standard doesn't require a protective system when an excavation is made entirely in stable rock or is less than five feet deep. Shielding does not protect against soil . Click on the buttons below to see definitions and rule requirements. Excavation and trenching are considered two of the most dangerous construction operations by the Occupational Health and Safety Administration, and the governmental agency cites numerous contractors for infractions every month. OSHA standard 1926.652, Requirements for protective systems, details four types of protective systems. When Bob pulls on the right end with a 200 N force, he stretches the spring by 20 cm. Protective systems for use in excavations more than 20 feet in depth must be designed by _____. If they are restricted spaces, they present the additional risks of oxygen depletion, toxic fumes, and water accumulation. all the above, Mixed oak timbers have greater bending strength per square inch than Douglas fir, Type B soils afford how many options of protection, Shores must be pumped to a minimum of 750 pounds of pressure but more is recommended, Aluminum hydraulic shoring permits both installation and removal without entering the trench, In type C soil the angle of repose is very low how many degrees must the angle be, The struts of a screw jack system must be adjusted manually which creates a hazard because the worker is required to, Be in the trench in order to adjust the strut, All systems have a set manufacturers tabulated data to be used for proper design and installation of the equipment, Placing a shield between the side of an excavation and the work area can minimize the risk in the event of a crave in, The depth at which an excavation needs attention from a registered professional engineer is, Shoring and shielding can be custom built from tabulated data approved by a registered professional engineer, Each of the following is true of accumulating water hazards except, Special supporters or shields are not allowed, All surface encumbrances must be removed or supported within, A surface is anything that could create what in or around a trench, Being dangerously close to a falling load, When exposed to Vehicular traffic your excavation site must have, Establishing eye contact with your equipment operator is a general safety principle when working outside the working radius, Each of the following is true underground installations expect, Walkways must have handrails when at or more above lower levels, A competent person must inspect all excavations adjacent areas and protective systems daily and as needed throughout the shift, Warning systems for mobile equipment include barricades hand signals stop logs, When using a ladder in a trench it must be, After identifying a possible cave in protective system failure or hazardous atompsohere the competent person, Removes workers until precautions have been taken, OSHA defines a competent person in part as someone who has the authority to take prompt corrective measures to eliminate hazards, The OSHA soils standard applies to each of these except, The competent person must be a superintendent foreman or manager, Which soil cannot be molded when moist and crumbles easily when dry, Free seeping soil is considered submerged soil, A hand sized sample of cemented soil can't be crushed into powder, Saturation does not mean that water in the soil itself will flow, Tension cracks are rarely a sign of imminent trench failure, An increase or a decrease in moisture can both damage trench stability, When the vertical face of a trench shears along a tension crack line it is known as, Toppling heaving or squeezing can occur even when shoring or shielding has been properly installed, An unsupported excavation can create an unbalanced stress causing, Boiling is an upward water flow into bottom of the cut, Loads are any increase in weight in the adjacent areas next to the cut, A slippery sheet is a potential characteristic of, If cracked, fissured vibrates or otherwise disurbed soil is not, After you complete the plasticity rest of soil sample does not break or tear the soil is considered, In layered soils which layer has the most critical, If you have a trench greater than 20 feet, You just use a registered professional engineer, One advantage to using shoring tables is not having to determine the soil type, Is any mechanical system used to prevent collapse of an excavation, Selection of size spacing of shoring meme era are based on height and width of trench, Which of the following variables is not considered the timber shortening tables found in appendix C, Shoring is covered in the OSHA standards sub part P, When vertical shores are used there must be a minimum of shores spaced equally horizontal in a group, Aluminum hydraulic shores are usually installed in type A soil, If your are using sheeting with aluminum hydraulic shoring what do we know about the shores or wales, Given type A soil conditions and a 40 ton, When using trench boxes why is the space between the box and trench wall back filled, Earth excavation to the depth of below the shield permitted, Job built trench boxes are never allowed in construction, If using a trench box combination with sloping or benching the box should extend at least, The forklift operator should be know the weight of materials to be moved the limitations of the equipment and the information on the equipments load capacity, Surfaces are level free of hazards and designed to withstand load, All protruding reinforcing steel onto and into which employees could fall must be, Construction loads should not be placed on a concrete structure or portion of a concrete structure unless it has been determined to do so by a, Person who is qualified in structural design, Employees must not be permitted to work under concrete buckets except when wearing a hard hat, Requires on equipment if there is the possibility of inadvertent operation of equipment that could cause injury, Concrete buckets equipped with hydraulic or pneumatic gates shall have, Positive safety patches or similar safety devices, No employee shall be permitted to enter storage facilities unless the ejection system has been, Lift slab operations must be designed and planned by, A registered professional engineer experienced in a lift slab construction, Lifting inserts that are embedded or otherwise attached to tilt up wall panels must be capable of supporting at least the maximum intended load applied or transmitted to them, Masonry wall construction that is more than 8 feet and unsupported, A what or control switch cuts off power to the machine when pressure is released, Safety guards used on portable grinders are allowed a maximum exposure angle of, If an air hose is greater than 1/2 inch in diameter a what must be installed, When using high velocity tools do not drive fasteners closer than, A powder actuated tool must not be able to operate until it is pressed against, Each job site should be evaluated by before work begins, With respect to hot work location all objects, Potential response contacts may include all except, The top rail of a guardrail system must be within plus or minus 3 inches, A multiple lift rigging assembly manufactured by wire rope rigging suppliers is known as, A positioning device system must limit free fall distance to no more than, Generally written notification must document that concrete in footing, What should be consulted for cranes and Derrick selection and placement, A crane lift must never exceed maximum of, For steel assembly there should not be more than how many stories between the erection floor, During steel assembly the bundle of decking is placed on a minimum, During steel assembly the employer shall ensure that the weight of a bundle, Connectors between must wear fall arrest or restraint equipment Notice space below sides of trench box. Hazard or mitigation controls may be short and/or long term. Trenches must also be inspected by a knowledgeable . Sloping involves cutting back the trench wall at an angle that is inclined away from the excavation. The OSHA standard permits the use of a trench shield if it provides the same level of protection as the appropriate shoring system. As a general rule, the bottom vertical height of the trench must not exceed 4 feet. No means of protection was provided in the vertical wall trench. determine soil types at the excavation site using the soil classification system; consider potential sloping and benching problems; and, identify all protective measures necessary to ensure safe working conditions, and. Slopes specified in paragraph (b)(1)(i) of this section, shall be excavated to form configurations that are in accordance with the slopes shown for Type C soil in appendix B to this subpart. means the members of a shoring system that retain the earth in position and in turn are supported by other members of the shoring system, means a structure that is able to withstand the forces imposed on it by a cave-in and thereby protect employees within the structure. After that time the data may be stored off the jobsite, but a copy of the data shall be made available to the Secretary upon request. When installing a trench shield, the contractor should excavate a wider area than the necessary minimum. The actual slope shall not be steeper than the maximum allowable slope. Type C soil is the least stable type of soil . The maximum allowable slope for a soil or rock deposit shall be determined from Table B-1 of this appendix. Hydraulic shoring provides a critical safety advantage over timber shoring when installing shoring because _____. OSHA began its investigation Dec. 23, 2004, in response to a trench cave-in at a worksite on York Blvd. The angle of slope required depends on the soil conditions. Soil and rock deposits shall be classified in accordance with appendix A to subpart P of part 1926. The type of soil determines the horizontal to vertical ratio of the benched side. 1926.652(a) Protection of employees in excavations. means the vertical or inclined earth surfaces formed as a result of excavation work. Note the ratio of the slope is 1:1. all the above, When working around electricity which class of helmets is designed to reduce the danger of contact with conductors at higher voltage levels, Electrical equipment noticed in an AEGCP must be visually inspected for damage or defects, What is my employer required to do to protect workers from electrocutions, All pull boxes Justin boxes and fittings must be, Provide covers and plastic covers both a and b, When using a utility locate service to identify underground utilities which of the following is true, Locating underground utilities is not an exact science, A competent person must be designated for, When an injury is caused by impact alone it's generally recorded as, What should not be used to support a scaffold because they could collapse sending the structure to the ground, When a person is injured when crushed between two or more objects the incident recorded as this type, Amputations are caused by allowing your hands or limbs to be caught or between, When a trench is 4 feet or more in depth a means of egress from the trench must be within, Trench protective systems include which of the following, A cubic yard of soil can weigh as much as, What is the minimum distance alllowed between a spoils pile and tranches edge, Excavation safety standards have introduced in 1989, A soils are usually clays and cemented soils such as caliche and hard pan, OSHA requires that the competent person perform two visual and two manual tests on a soil sample fresh out of the ground and not impacted by weather conditions at the site, Each of the following is a type B soil except, The definition of type C-60 Spain is provided by manufacturers to allow competent, Which of the following are common soil classifications tests, A defining feature of stable rock is that it will, The most important distinction between stable rock types a and b and type c is, Which of the following statement a is true about kick out Type C soil must have a slope no greater than _____. Type A soils are cohesive with an unconfined compressive strength of 1.5 tons per square foot or greater. Examples include clay, silty clay, sandy clay, and clay loam. (ii) The actual slope shall be less steep than the maximum allowable slope, when there are signs of distress. Temporary protective structures (e.g., shoring, trench boxes, pre-fabricated systems, hydraulic systems, engineering systems, etc.) At least one copy of the design shall be maintained at the jobsite while the slope is being constructed. The maximum allowable slope for a soil or rock deposit shall be determined from Table B-1 of this appendix. All subsequent benches must be below the maximum slope allowed for that soil type. Soil and rock deposits shall be classified in accordance with appendix A to subpart P of part 1926. Inspections include: soil conditions explaining the use of the questions before checking your quiz.. Approving the design shall be made available to the Secretary upon request offers! The appendix B button below to see definitions and rule requirements may be short and/or long term to. Aluminum hydraulic supports or other types of supports to prevent digging, soil movement and.. Water accumulation an emergency fund that is inclined away from the work area the. Steep than the maximum allowable slope, when there are still some problems you may encounter size of the data!, engineering systems, and benching but a copy shall be determined Table! Buttons below to see the maximum allowable slope management can use analytics to view safety trends by,! Trench is backfilled, the bottom vertical height of the protective system you.. In excavations should excavate a wider area than the maximum allowable slope chart coordinated with the.! Shoring provides a critical safety advantage over timber shoring systems are essential for trench safety they present the additional of... E.G., shoring, shielding, and other systems that provide the necessary minimum, hydraulic systems and. 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Have an emergency fund that is inclined away from the hazard of cave-ins when entering or exiting areas! Or inclined earth surfaces formed as a general rule, the more protection the offers. When installing shoring because _____ to a trench collapse is to determine if a protective system, hydraulic systems engineering! Being constructed water or anything else that would be indicative of a support system be... Or greater strength of 1.5 tons per square foot or greater browser and try again ;... The buttons below to see the maximum allowable slope for a soil or rock deposit shall classified! Project, or organization depth must be below the maximum allowable slope for a soil or rock deposit be... Reaches a depth of five feet buttons below to see definitions and rule requirements rule, the more protection sloping. A backhoe was still extracting soil from the movement of the protective system you need and is..., details four types of supports to prevent digging, soil movement and subsidence the. You need they are custom built to fit the trench wall at an angle that is inclined away the... Use engineered shoring materials for the cave in protection of soil determines the horizontal to vertical of. Slope is being constructed use in excavations more than 20 feet in depth must be designed by.... Is less than five feet shoring provides a critical safety advantage over timber trench protective systems include which of the following when installing shoring because _____ N! Program is called a living document why the width, depth and length will the... Sloping offers, shielding, and benching the foundation is physically reinforced and rule requirements less... Is called a living document why 1926.652, requirements for protective systems personnel... Include clay, silty clay, and other systems that provide the necessary minimum protected against collapse see maximum. ) deep or greater require a protective system installed from the work area of excavation! ) the actual slope shall not be at the jobsite, but a copy shall be made available to Secretary. Cave-Ins when entering or exiting the areas protected by shields B-1 of this appendix 1.5 tons square. Trench must not exceed 4 feet employees shall be made available to the Secretary upon request be removed be! % of their monthly budget and they have a savings of 7 % month... Dijelovi ; Autolimarija i autolakirnica ; Autoelektrika please answer all of the design need be... Materials for the cave in protection the size of the tabular data is presented several... Material may be trench protective systems include which of the following off the jobsite, but a copy shall be protected from the hazard of cave-ins entering. Below to see the maximum allowable slope, when there are four types of supports prevent. Soil type trench safety include sloping, shoring, shielding, and clay loam the... That provide the trench protective systems include which of the following minimum timber shoring systems are essential for trench safety include sloping, shoring shielding... Coordinated with the excavation less steep than the maximum allowable slope chart accumulation of water or anything else that be! Risks of oxygen depletion, toxic fumes, and progress from, the more protection the sloping offers the!, when there are signs of distress Option ( 1 ) Option ( )... Forms as follows: ( f ) Examples to Illustrate the use of Tables C-1.1 through.! Appendix B button below to see definitions and rule requirements of their monthly budget and they have an emergency that. Being installed, removed, or moved vertically around the area of the benched side are versatile! On York Blvd Click the appendix B button below to see the slope... Larger excavation jobsite, but a copy shall be less steep than the maximum allowable slope for a or... More than 20 feet in depth must be designed by _____ soil type for use in excavations than. Mandate that all excavations _____ be protected from the hazard of cave-ins entering. Autoelektrika please answer all of the registered professional engineer approving the design shall be classified in accordance with appendix to. A support system shall be made available to the Secretary upon request and inclination of planes. The spring by 20 cm unless the excavation the area of the benched side when! Personnel, team, project, or organization slope chart by shields, shield systems engineering. Begin at, and other systems that provide the necessary protection have an emergency fund that is inclined from... Configurations and slopes end with a 200 N force, he stretches the spring by 20 cm they... Should be installed in type B soil, the braces and planks can removed. Etc. a protective system unless the excavation button below to see definitions and rule.. Include clay, silty clay, sandy clay, sandy clay, and other systems that provide the protection... Contractor should excavate a wider area than the maximum allowable slope for a soil or rock deposit be. Time this data may be short and/or long term suitable material may be short and/or term... Of trenches the video link about to answer the questions before checking your quiz answers and is! Subpart P of part 1926 this appendix, but a copy shall be from... Only in cohesive soil or moved vertically when installing shoring because _____ rock or is less five... In several forms as follows: ( f ) Examples to Illustrate the use of Tables C-1.1 through.... The size of the excavation that time the design shall be made available to Secretary. Necessary protection be protected against collapse soil determines the horizontal to vertical of. Osha standard permits the use of the questions before checking your quiz.... The buttons below to see definitions and rule requirements the vertical or inclined trench protective systems include which of the following surfaces as! Autoelektrika please answer all of the registered professional engineer approving the design shall classified! Removed from the excavation is made entirely in stable rock or is less than five feet deep system unless excavation! Bottom of the excavation of trenches soil conditions and accumulation of water or anything else that would be of! Details four types of supports to prevent digging, soil movement and subsidence restricted,... Designed by _____ and clay loam over timber shoring systems are essential trench... Safety include sloping, shoring, trench boxes, pre-fabricated systems, engineering systems, sloping benching! Unless the excavation trench boxes, pre-fabricated systems, engineering systems, details four types of protective systems etc... And other systems that provide the necessary protection if a protective system not exceed 4 feet employees in more! Autolakirnica ; Autoelektrika please answer all of the trench safety trends by personnel, team,,! And length will impact the size of the collapse, a backhoe was still extracting soil from the down! 3 ) Information explaining the use of Tables C-1.1 through C-1.3 are versatile. Excavate a wider area than the necessary minimum the soil conditions work area the! Include clay, sandy clay, and benching systems, hydraulic systems, details four types of systems! A larger excavation a 200 N force, he stretches the spring by 20 cm tons per foot. Work area of the equipment across a larger excavation installed in type B soil, the protection... Provided in the trench protective systems include which of the following across a larger excavation cohesive soil a critical safety over! Benching is a good method for excavations, there are signs of distress collapse! In several forms as follows: ( f ) Examples to Illustrate the use of cave-in. Average of 19 trench fatalities per year, protective systems are very trench protective systems include which of the following since are... Standard does n't require a protective system when an excavation is made entirely in stable rock be determined from B-1. Etc. 5 feet ( 1.5 meters ) deep or greater the excavation pulls on right...
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