trench protective systems include which of the following

OSHA stipulates maximum allowable slopes for each soil type in the work area. Underpinning should be conducted only under the direction and with the approval of a registered professional engineer. No horizontal bracing was used. Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Three Primary Protection Methods In Excavation. document.getElementById( "ak_js_2" ).setAttribute( "value", ( new Date() ).getTime() ); Safety and savings work together with Foresight Insurance and Safesite. Footnote(1) Numbers shown in parentheses next to maximum allowable slopes are angles expressed in degrees from the horizontal. With an average of 19 trench fatalities per year, protective systems are essential for trench safety. means tables and charts approved by a registered professional engineer and used to design and construct a protective system. The flatter the angle, the more protection the sloping offers. Each employee in an excavation shall be protected from cave-ins by an adequate protective system designed in accordance with paragraph (b) or (c) of this section except when: Excavations are made entirely in stable rock; or. The following figures are a graphic summary of the requirements contained in subpart P for excavations 20 feet or less in depth. 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. When surcharge loads from stored material or equipment, operating equipment, or traffic are present, a competent person shall determine the degree to which the actual slope must be reduced below the maximum allowable slope, and shall assure that such reduction is achieved. They have an emergency fund that is 6% of their monthly budget and they have a savings of 7% per month. Benching cutting the sides of an excavation to form one or a series of horizontal levels or steps usually with vertical or near vertical surfaces between levels. Hydraulic shoring should be checked at least once per shift for leaking hoses and/or cylinders, broken connections, cracked nipples, bent bases, and any other damaged or defective parts. Want to read all 2 pages? How far does Carlos's end of the spring move? All excavations are hazardous because they are inherently unstable. Shoring systems may also be required to support adjacent structures, like buildings, walls, sidewalks, or pavement. Although sloping and benching is a good method for excavations, there are still some problems you may encounter. Hydraulic shoring provides a critical safety advantage over timber shoring because workers do not have to enter the trench to install or remove hydraulic shoring. Shielding systems include trench boxes, steel plates, and/or combination of protective systems. Shields can be permanent structures or can be designed to be portable and moved along as work progresses. in Pearland. If they are restricted spaces, they present the additional risks of oxygen depletion, toxic fumes, and water accumulation. In May of last year, the U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) cited Dillon after a worker installing residential sewer pipes died when the trench around. "Certain systems are good to a certain depth, and then you need other systems to take over after that," said Lindsley. (2) Additional requirement for shield systems used in trench excavations. Protective system integrity. (ii) Designs shall be in written form and shall include at least the following: (A) The magnitude of the slopes that were determined to be safe for the particular project; (B)The configurations that were determined to be safe for the particular project; and. [8] ENR used data on transportation, sewer, hazardous waste and water to rank firms as heavy contractors. Hazardous atmospheres. Excavations shall be sloped at an angle not steeper than one and one-half horizontal to one vertical (34 degrees measured from the horizontal), unless the employer uses one of the other options listed below. What is the relationship between electronegativity and the polarity of a chemical bond? Soil and rock deposits shall be classified in accordance with appendix A to subpart P of part 1926. After that time the design need not be at the jobsite, but a copy shall be made available to the Secretary upon request. both a and b, Training for qualified persons is the same as for unqualified person, A licensed electrician automatically meet the definition of a qualified person, A qualified person designation is both take and, Owners of non dwelling electrical equipment that is likely to require examination, The three limits of approach boundaries are, NFPA 70E states that all PPE must meet one of the three levels, Tools used for working on electrical equipment should be, Which below are steps in effective inspections, The accident investigation. 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. Installation of a support system shall be closely coordinated with the excavation of trenches. A or B, Bulldozer and scraper blades end loader buckets dump bodies, Flammable liquids have flash points below, OSHA specifies that for overhead power lines rated 50 kV, Must be provided on spur railroad tracks where a rolling car could contact other cars, Operating levers controlling hoisting or dumping devices on haulage, A latch device to prevent accidental starting or tripping, No person must use any motor vehicle equipment having an obstructs view, An observer to signal that it is safe to reverse, All haulage vehicles whose pay load is loaded by means of cranes power shovels, Pneumatic tired earth moving haulage equipment who's maximum exceeds 15miles, All earthmoving equipment must have a service braking, When steel tube piles are being blown out, Kept well beyond the range of falling materials, Must be provided across the top of the head block to prevent, Requires for the leads to prevent the hammer from being raised, First aid treatment and planning is only necessary if emergency medical, The area along the waterfront edge of the pier or wharf, The raised frame as around a hatchway in the deck to keep out water, Industrial truck training must consist of all but, Heat from an electric arc a stream of ionized gas called plasma or burning gases, The most common and simplest type of welding today is, A process by which two pieces of of metal are joined, Activity which depends on the heat produced by the combustion of a fuel gas, In the arc welding process eye exposure to intense visible light, Metal fume is principally associated with what chemical substance, A colorless and tasteless cannot be readily detected by the senses, Vapors of these solvents are a concern in welding and cutting At least one copy of the design shall be maintained at the jobsite while the slope is being constructed. Sloping involves cutting back the trench wall at an angle that is inclined away from the work area of the excavation. Timber and aluminum hydraulic. 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. OSHA standard 1926.652, Requirements for protective systems, details four types of protective systems. Benching is similar to sloping and requires the removal of material from the face of an excavation. These fatalities and accidents are preventable. Short term exposure means a period of time less than or equal to 24 hours that an excavation is open. They also spend 7% of the budget on clothing each month. Where the working area of an excavation is constantly moving, as in laying a conduit, shield systems or trench boxes may be the more appropriate protective devices to use. b. Where the working area of an excavation is constantly moving, as in laying a conduit, shield systems or trench boxes may be the more appropriate protective devices to use. (ii) The tabulated data shall be in written form and shall include all of the following: (A) Identification of the parameters that affect the selection of a sloping or benching system drawn from such data; (B) Identification of the limits of use of the data, to include the magnitude and configuration of slopes determined to be safe; (C) Explanatory information as may be necessary to aid the user in making a correct selection of a protective system from the data. Designing a protective system can be complex because you must consider many factors: soil classification, depth of cut, water content of soil, changes due to weather or climate, surcharge loads such as spoil and other materials used in the trench, and other nearby operations such as heavy equipment and vehicle traffic. Trench shields are usually constructed with sidewalls held apart by steel or aluminum spreaders. 400 Words. A cave-in occurred, fatally injuring one employee and causing serious facial injuries to the other. means a pre-engineered shoring system comprised of aluminum hydraulic cylinders (crossbraces) used in conjunction with vertical rails (uprights) or horizontal rails (wales). At least one copy of the tabulated data which identifies the registered professional engineer who approved the data, shall be maintained at the jobsite during construction of the protective system. Soil classification. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. 1926.652(b)(3) which requires other tabulated data to be followed. The sides of an excavation are dug to form horizontal levels or steps. Hydraulic shoring should be checked at least once per shift for leaking hoses and/or cylinders, broken connections, cracked nipples, bent bases, and other damaged or defective parts. It is allowed only if a trench supports or shield is used. Maximum allowable slopes, and allowable configurations for sloping and benching systems, shall be determined in accordance with the conditions and requirements set forth in appendices A and B to this subpart. Protective systems are just one area to consider for trench safety and excavation. The angle of slope required depends on the soil conditions. Shielding protects workers by using trench boxes or other types of supports to prevent soil cave-ins. (2) Option (2)-Determination of slopes and configurations using Appendices A and B. Materials and equipment used for protective systems shall be free from damage or defects that might impair their proper function. (i) Excavations shall be sloped at an angle not steeper than one and one-half horizontal to one vertical (34 degrees measured from the horizontal), unless the employer uses one of the other options listed below. 2. (i) Sloping and benching systems not utilizing Option (1) or Option (2) or Option (3) under paragraph (b) of this section shall be approved by a registered professional engineer. 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. A safety and health program changes as an organization changes. 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. Given that E=0.52VE^{\circ}=0.52 \mathrm{~V}E=0.52V for the reduction Cu+(aq)+e\mathrm{Cu}^{+}(a q)+e^{-}Cu+(aq)+e Cu(s)\longrightarrow \mathrm{Cu}(s)Cu(s), calculate E,GE^{\circ}, \Delta G^{\circ}E,G, and KKK for the following reaction at 25C25^{\circ} \mathrm{C}25C : 2Cu+(aq)Cu2+(aq)+Cu(s)2 \mathrm{Cu}^{+}(a q) \longrightarrow \mathrm{Cu}^{2+}(a q)+\mathrm{Cu}(s) The service requires full JavaScript support in order to view this website. cause damage from the movement of the equipment across a larger excavation. The excavation must comply with one of the following four options in Sec. Use Protective Systems. The type of soil determines the horizontal to vertical ratio of the benched side. (i) Design of support systems, shield systems, or other protective systems that are drawn from manufacturer's tabulated data shall be in accordance with all specifications, recommendations, and limitations issued or made by the manufacturer. 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. If that situation occurs, the slope shall be cut back to an actual slope which is at least horizontal to one vertical (H:1V) less steep than the maximum allowable slope. These daily inspections include: Soil conditions and accumulation of water or anything else that would be indicative of a cave-in. Benching protects workers from cave-ins by creating horizontal levels or steps, usually with vertical or near-vertical surfaces between levels. means the vertical members of a trench shoring system placed in contact with the earth and usually positioned so that individual members do not contact each other. Any excavation that is more than 20 feet deep requires a protective system designed and approved by an engineer. ", means 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 cave-ins. For shallower installations, contractors will typically use lightweight aluminum trench boxes, modular trench boxes or lightweight vertical . Designs of support systems, shield systems, or other protective systems shall be selected from and be in accordance with tabulated data, such as tables and charts. Smith, Michael Abbott, Water Supply and Stream Management 202.12E. OSHA requires the competent person to classify the soil using at least one visual and one manual analysis, as outlined by OSHA standards or allowed by the ASTM. All the above. The first step in protecting workers from a trench collapse is to determine if a protective system is required. www.constructionequipment.com is using a security service for protection against online attacks. (iii) At least one copy of the design shall be maintained at the jobsite during construction of the protective system. Before You Dig: Excavation Preplanning and Permitting, Getting Started with Excavation Risk Management, Scheduling Excavation and Trenching Inspections. If you are not using protective systems or equipment while working in trenches or excavations at your site, you are in danger of suffocating, inhaling toxic materials, fire, drowning, or being crushed by a cave-in. After that time this data may be stored off the jobsite, but a copy shall be made available to the Secretary upon request. After that time the design need not be at the jobsite, but a copy shall be made available to the Secretary upon request. The trench and excavation work that takes place in utility projects represents some of the most dangerous jobs in construction. Features include: A smooth and comfortable ride. Limits compaction. High traction characteristics are ideal for loader applications. . 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. (1) Option (1)-Allowable configurations and slopes. Employers can choose the most practical method for the particular circumstance, but that system must meet the required performance criteria. means the accidental release or failure of a cross brace. A Cable Trench is located under the Switch/Relay Room, Control Room and Battery Room to house the communication, control and power cables between the substation's operational areas as well as transport power to external high voltage switching towers. 3. Note collapse of the benching. Unsafe Access/Egress. (i) Designs of support systems, shield systems, or other protective systems shall be selected from and be in accordance with tabulated data, such as tables and charts. 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 (iii) Manufacturer's specifications, recommendations, and limitations, and manufacturer's approval to deviate from the specifications, recommendations, and limitations shall be in written form at the jobsite during construction of the protective system. Deep and long trenches are probably better suited to timber shoring than any other form of protective system. (i) Designs of sloping or benching systems shall be selected from and be in accordance with tabulated data, such as tables and charts. Excavations of earth material to a level not greater than 2 feet (.61 m) below the bottom of a shield shall be permitted, but only if the shield 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 shield. Protective systems for use in excavations more than 20 feet in depth must be designed by _____. Option 2: Sec. 1926.652(b)(3) which requires Appendices A and B to be followed. Potential hazards include: Regardless of the type of protective system, the trench should include a means of egress, such as stairs, a ladder, or a ramp. maximum allowable slopes for each soil type, Dig Deep: The Ultimate Excavation Safety Guide, How Employee Engagement Unlocks Safety Program Performance, 10 Things Safety Pros Must Know About the Ex Mod, The Ultimate Guide to Safety Reporting & KPIs, Safesites Step-by-Step Guide to Safety Program Digitization. True. (ii) Deviation from the specifications, recommendations, and limitations issued or made by the manufacturer shall only be allowed after the manufacturer issues specific written approval. This type of protective systems involves excavating the sides of a trench to form one or a series of horizontal levels or steps. (i) 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 This appendix contains specifications for sloping and benching when used as methods of protecting employees working in excavations from cave-ins. OSHA standards mandate that all excavations 5 feet or deeper be protected against collapse. What is a common hazard when multiple benches have been created for an excavation? 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. 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). 1926.652 - Requirements for protective systems. Please answer all of the questions before checking your quiz answers. As a general rule, the bottom vertical bench height of a multiple-benched trench must not exceed _____. Before temporary removal of individual members begins, additional precautions shall be taken to ensure the safety of employees, such as installing other structural members to carry the loads imposed on the support system. 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. According to the video clip from the Economist, why is the deep sea "the final frontier (1) Information is presented in tabular form in Tables C-1.1, C-1.2 and C-1.3, and Tables C-2.1, C-2.2 and C-2.3 following paragraph (g) of the appendix. For every 1 feet horizontally, the height of the slope increases by 1 foot. Trench protective systems include which of the following: B. Sloping, benching, shoring, trench box B. Sloping , benching , shoring , trench box Upload your study docs or become a Course Hero member to access this document Continue to access End of preview. (iii) When surcharge loads from stored material or equipment, operating equipment, or traffic are present, a competent person shall determine the degree to which the actual slope must be reduced below the maximum allowable slope, and shall assure that such reduction is achieved. Per OSHA's Trenching and Excavation Construction eTool, here are four ways to avoid excavation hazards: 1. You will be redirected once the validation is complete. In order to use the data presented in this appendix, the soil type or types in which the excavation is made must first be determined using the soil classification method set forth in appendix A of subpart P of this part. A manual analysis could include feeling the soil in your hands or using a penetrometer. A safety and health program is called a living document why. Members shall be released slowly so as to note any indication of possible failure of the remaining members of the structure or possible cave-in of the sides of the excavation. This seems to be more of a trend today. Find the three numbers. However, in this case, a competent person must examine the ground and find no indication of a potential cave-in. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); We're a group of safety and tech professionals united in our desire to make every workplace safer. Surcharge loads from adjacent structures shall be evaluated in accordance with 1926.651(i). If a customer selects 3 of these pens at random, what is the probability that: means those requirements which are compatible with standards of practice required by a registered professional engineer.

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