Solution Summary: Shoring Equipment for Trenching
Shoring equipment is designed to stabilize and provide structure for trenches when work must be completed below earth’s surface.
Description:
Shoring equipment, along with techniques such as sloping, benching, and shielding with trench boxes, use engineering controls to create safer in-ground working environments. Shoring uses pneumatic or hydraulic cylinders to exert pressure on and stabilize trench walls to prevent cave-ins while work is performed below ground. Using shoring equipment makes the trench much less likely to collapse. With a stable work environment, tasks can be completed more confidently and efficiently as less time and energy will be spent worrying about trench structure failure.
Excavations must be inspected by a competent person and cave-in protection, such as shoring, must be used when there is a potential for a cave-in or a trench is greater than five feet deep. Using shoring improves the structural integrity of trenches and reduces the risk of collapse and injury or death. Working in trenches with unprotected walls as much as five feet below ground surface may be allowed if in stable rock or if determined by a competent person to not pose a risk of cave-ins. The competent person may still recommend use of shoring for some soil and work conditions, even though the trench is not greater than 5 feet deep. Protection for trenches that are 20 or more feet deep must be designed or approved by a registered professional engineer. Even with shoring, workers still need to be observant of their surroundings and exit any trenches that they believe to be unstable until the problem is corrected.
Pro-Tec Aluminum Hydraulic Shoring
- Rail Length: 1.5, 3.5, 5, 7, 8, 12, 16 feet
- Cylinder Width: 17-27, 22-36, 28-46, 34-55, 40-64, 52-88 inches
- Weight per Rail: 20-234 pounds
- Extension Length: 11-56 inches
Trench Tech Hydraulic Shoring
- Rail Length: 1.5, 2, 3.5, 5, 7, 9, 12, 16 feet
- Cylinder Width: 17-27, 22-36, 28-46, 34-55, 42-69, 52-88 inches
- Weight per Rail: 20-234 pounds
- Extension Length: 5-56 inches
The Icon Group Hydraulic Shoring
- Rail Length: 1.5, 3.5, 5, 7, 8, 12, 16 feet
- Cylinder Width: 17-27, 22-36, 28-46, 34-55, 40-64, 52-88 inches
- Weight per Rail: 21-97 pounds
- Extension Length: 10-36 inches
GME Hydraulic Shoring
- Rail Length: 2, 3, 4, 5, 6, 7, 8, 10, 12 feet
- Cylinder Width: 20-28, 28-44, 30-60, 47-82 inches
- Weight per Rail: 12-25 pounds
Guardian Traffic Services Pneumatic Shoring
- Cylinder Width: 18-27, 23-36, 30-48, 42-66, 60-96, 90-120, 114-144 inches
- Weight per Rail: 12-40 pounds
Risks Addressed:
An excavation is a man-made cavity in the ground and a trench is an excavation that is deeper than it is wide. Working in trenches increases the risk of injury and death and a significant number of worker injuries and fatalities are directly related to trench cave-ins. Many factors must be considered when the creation of a trench begins, including soil type, amount of moisture present, effect of vibration from equipment and nearby traffic, surcharge load (i.e. excessive weight that can put pressure on the walls of the trench), previous excavation, and weather for the area. Many methods may be used to protect against cave-ins, including the use of shoring equipment. Shoring equipment provides stability for the walls of the trench by preventing movement of soil, underground utilities, roadways and foundations. Shoring equipment therefore creates a safer work environment (Trenching Safety, 2010).
According to NIOSH, Bureau of Labor Statistics data from 2000 to 2009 indicate that an average of 35 workers per year died in trenching or excavation cave-ins in the United States (NIOSH, 2011). The NIOSH report also noted a study based on an analysis of OSHA data from 1997−2001 that showed 64 percent of fatalities in trenches occurred at depths of less than 10 feet (Arboleda and Abraham 2004). Another study that used OSHA inspection data showed that lack of a protective system was the leading cause of trench-related fatalities (Deatherage et al. 2004).
OSHA has focused heavily on excavation and trenching operations over the past decade. Such operations can be dangerous past four feet deep with cave-ins causing serious injury or death. More serious incidents are likely to occur when work is performed at a depth of six to nine feet. With the average cubic yard of dirt weighing approximately one ton, a person will likely not be able to breathe due to the pressure of the dirt on his or her chest. Even if a person maintains the ability to breathe during a cave-in, it is not guaranteed that the victim will survive injuries from compression of the lungs and other organs. OSHA reviewed cases from 2004 and found they had issued over $7 million in penalties for accidents that most likely could have been avoided (Griffin, 2005).
Rule 943 of the state of Michigan OSHA standards and Federal OSHA standards (29 CFR 1926 subpart P) mandate the use of trench support systems. During the process of providing trench support, ample space must be allowed to prevent sliding, falling or kickout when using a brace or trench jack. In addition, with situations involving unstable soil, jacks should only be removed from above the trench once all workers have exited the trench area. Specific regulations exist to insure support systems can effectively resist the forces opposing the trench at the maximum depth point (MiOSHA, 2005).
How Risks are Reduced:
Shoring is the process of creating safer work environment by providing a support system for trenches. Depending on conditions, including soil type, shoring cylinders may be expanded directly against trench walls, against rails positioned vertically in the trench, or against sheets of plywood or metal positioned against the trench walls. Shoring support systems work by providing stability for the walls that have been created in the trench and reducing the risk of collapse.
Even with shoring equipment, workers still need to be observant of their surroundings and exit any trenches that do not seem stable until the problem is corrected.
While there are no peer-reviewed data on these specific controls, manufacturers’ testing indicates accidents can be significantly reduced through the proper use of shoring equipment. The extent of the reduction is dependent on the type of work being performed, the depth and width of the trench, the soil composition, and the shoring equipment being used.
The shoring support systems prevent the movement and/or collapse of soil, underground utilities, roadways and foundations. Work can therefore be safely accomplished below grade level (OSHA Technical Manual, 1999).
Effects on Productivity:
Shoring equipment use has helped to reduce the number of injuries and fatalities in trench work areas. Shoring equipment stabilizes trench walls and provides a safer work environment. Avoiding cave-ins ensures production will not be disrupted by a potentially catastrophic event that can significantly damage a company. A safer work climate greatly improves company morale, reduces absenteeism and ensures company viability.
Contributors:
Andrew Kingston and Michael R. Cooper - Aria Environmental, Inc.
Bruce Lippy - CPWR
Availability
GME Hydraulic Shoring
To obtain information, visit http://www.gme-shields.com
or contact 1-800-248-2054
The Icon Group Hydraulic Shoring
To obtain information, visit http://www.iconjds.com
or contact 1-800-836-5011
Pro-Tec Aluminum Hydraulic Shoring
For more product information
http://www.pro-tecequipment.com
or contact 1-800-292-1225
NIOSH Workplace Solutions Sheet
The National Institute of Safety and Health (NIOSH) has published a series of “Workplace Solutions”, which are easy-to-understand recommendations from NIOSH research results. Related to this Construction Solution, please find more information on:
Preventing Worker Deaths from Trench Cave-ins
Trench Tech Hydraulic Shoring
To obtain information, visit http://www.shoringsolutions.com
or contact 1-800-443-6832
