Protective system means
interior fittings and devices intended to restrain the occupants
. … Protective systems include support systems, sloping and benching systems, shield systems, and other systems that provide the necessary protection.
What are trench protective systems?
A shield, also known as a trench box, is another
common protective system used by contractors
. Trench boxes are not designed to prevent cave-ins, but rather serve to “shield” workers within the structure should a cave-in occur.
What are the primary types of protective systems?
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 …
What is protective systems in excavations?
A shoring system
is used to support the face of an excavation and to prevent movement of soil, underground utilities, roads, and foundations. A shoring system is typically used when sloping is an inadequate solution due to the depth of the cut or the location.
What are 3 main protection methods against cave-ins?
SLOPE IT.
To prevent cave-ins: SLOPE or
bench trench walls
.
SHORE trench walls with supports
, or. SHIELD trench walls with trench boxes.
What type of soil Cannot be benched?
Type C soil
cannot be benched.
What is the basic types of shoring?
Shoring Types. Shoring is the provision of a support system for trench faces used to prevent movement of soil, underground utilities, roadways, and foundations. … There are two basic types of shoring,
timber and aluminum hydraulic
.
How deep can you dig without shoring?
Trenches
5 feet (1.5 meters) deep
or greater require a protective system unless the excavation is made entirely in stable rock. If less than 5 feet deep, a competent person may determine that a protective system is not required.
At what depth is a trench considered a confined space?
In the United States, any pit or trench with a
depth equal to or greater than 4 feet
is classified as a permit-required confined space.
How deep can you dig without a trench box?
Trenches with a depth of
5 feet
(1.5 meters) or greater need a protective system unless the entire excavation is in stable rock. If there is anything less than 5 feet, it is up to a competent person’s discretion to determine if there is a need for a protective system.
When should shoring be installed?
All shoring should be installed
from the top down and removed from the bottom up
. 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. FIGURE V:2-8.
What are some of the dangers of excavations?
- Cave-ins. Trench collapses kill an average of two workers every month, making this a serious threat to worker safety. …
- Falls and falling loads. Workers and work equipment can fall into an excavated area. …
- Hazardous atmospheres. …
- Mobile equipment. …
- Hitting utility lines.
What can create a caught between hazard?
Caught-in/between hazards are caused when
a worker is compressed between or gets caught in equipment or objects
. It also includes when a worker is killed by getting caught, struck or crushed from materials, equipment or a collapsing structure.
What is the greatest danger associated with excavations?
Cave-ins pose
the greatest risk in trenching and excavation operations, and are much more likely than other excavation-related accidents to result in worker fatalities. Other potential hazards include falls, falling loads, hazardous atmospheres, and incidents involving mobile equipment.
What are the standard methods of cave in protection?
- Sloping.
- Temporary protective structures (e.g., shoring, trench boxes, pre-fabricated systems, hydraulic systems, engineering systems, etc.)
Which type of soil is the most cohesive?
Clay
is a very fine grained soil, and is very cohesive. Sand and gravel are course grained soils, having little cohesiveness and often called granular. Generally speaking, the more clay that is in the soil being excavated, the better the trench walls will hold up. Another factor in soil cohesiveness is water.
