R 408.40926 Definitions; S.

Rule 926. (1) “Sheeting” 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. (2) "Sheet piling" means a continuous row of timber or steel piles driven in close contact to provide a tight wall to resist lateral pressure of water, adjacent earth, or other materials. (3) “Shield” or “shield 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. Shields can be permanent structures or can be designed to be portable and moved along as work progresses. Additionally, shields can be either premanufactured or job-built in accordance with R 408.40932, R 408.40942, R 408.40943, R 408.40945, and R 408.40953. Shields used in trenches are usually referred to as trench boxes or trench shields. (4) “Shoring” or “shoring system” 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. (5) "Sides" sometimes called faces or walls, mean the vertical or inclined earth surfaces formed as a result of excavation work. (6) "Slope" means the acute angle formed by the side of a trench or excavation and the horizontal plane. (7) "Soil" means any of the following: (a) "Clay" means a very fine textured soil that derives its resistance to displacement from cohesion and may be: (i) "Soft clay" means a clay-type soil that has an unconfined strength of less than 1.0 ton per square foot. (ii) "Medium clay" or "plastic" means a clay-type soil that has a minimum unconfined strength of 1.0 ton per square foot. (iii) "Firm soil" means a clay-type soil that is resistant to forces causing rupture or displacement. A firm clay has a minimum unconfined strength of 1.5 tons per square foot. (iv) "Stiff clay" means a clay-type soil that is very resistant to forces causing rupture or displacement. A stiff clay has a minimum unconfined strength of 2.5 tons per square foot. (b) "Fill" means a manmade soil condition that may be constructed of any type of soil or combination thereof. (c) "Granular soil" means a coarse grained soil that does not possess cohesion but derives its strength from internal friction. (d) "Organic soil" means a soil that contains significant amounts of peat, muck, or marl. (e) "Running soil" means any type of soil that has insufficient strength to stand unsupported. Running soil tends to run or slough into the excavation as the excavation is being dug. (8) "Stringers" mean the horizontal members of a trench shoring system whose sides bear against the uprights or earth. (9) “Structural ramp” means a ramp built of steel or wood, usually used for vehicle access. Ramps made of soil or rock are not considered structural ramps. (10) “Support system” means a structure such as underpinning, bracing, or shoring, which provides support to an adjacent structure, underground installation, or the sides of an excavation.