New York Codes, Rules and Regulations › Title 12 - DEPARTMENT OF LABOR › Chapter I - Industrial Board Of Appeals › Subchapter A - The Industrial Code › Part 23 - Protection In Construction, Demolition And Excavation Operations › Subpart 23-4 - Excavation Operations › Section 23-4.2 - Trench and area type excavations

Current through Register Vol. 46, No. 28, July 10, 2024
(a)
					 Whenever any person is required to work in or is lawfully frequenting any
					 trench or excavation five feet or more in depth which has sides or banks with
					 slopes steeper than those permitted in Table I of this Subpart, such sides or
					 banks shall be provided with sheeting and shoring in compliance with this Part
					 (rule). Such sheeting and shoring system shall be in contact with the sides or
					 banks of such trench or excavation. A designated person shall carefully inspect
					 such sheeting and shoring at least once each day and more frequently in the
					 event of rain, the presence of additional surface or ground water from any
					 source, excessive ground vibrations or whenever additional loads of any kind
					 have been imposed near or adjacent to such excavation. Additional protection
					 against slides and cave-ins shall be provided whenever necessary. Any trench or
					 excavation in clay, sand, silt, loam or nonhomogenous soil which has sides or
					 banks more than three feet but less than five feet in depth shall be provided
					 with side or bank protection in compliance with this Part (rule). Such side or
					 bank protection shall not be required where an employer maintains on file at
					 the excavation site a dated certification in writing by a designated person who
					 is qualified by training and experience indicating that such person has
					 examined the sides and banks and has found them to be stable and not subject to
					 failure or cave-in. Such certification shall be available for examination by
					 the commissioner.
(b) Where the
					 sides or banks of a trench or area type excavation may be sloped back without
					 causing subsidence or damage to buildings, structures, utilities, roads,
					 streets, highways or similar facilities, sloping of the excavation sides or
					 banks may be used as protection in lieu of the sheeting and shoring required by
					 this Part (rule), provided such sloping conforms to the values set forth in
					 Table I of this Subpart. Such sloping of the excavation sides or banks may be
					 used in combination with sheeting and shoring. When such a combination is used,
					 a level bench at least 24 inches in width shall be left between the toe of the
					 sloped section and the braced section. The sheeting of the braced section shall
					 extend at least 12 inches above the elevation of such level bench.
(c) Any unbraced sloped excavation which
					 extends below the ground water table, especially adjacent to rivers, reservoirs
					 or other bodies or sources of free water, shall be under the direct supervision
					 of an experienced person designated by the employer.
(d) In any excavation with a combination of
					 sloped unbraced sides or banks near the surface and vertical sheeted and shored
					 sides or banks near the bottom, the steepest allowable slope of such unbraced
					 portion of the sides or banks shall be based on the total excavation depth.
					 (See Table I of this Subpart.)
(e)
					 Where any side or bank of an excavation is undercut and has a reverse slope
					 toward the trench centerline creating a vertical load on the sheeting and
					 shoring, such sheeting and shoring shall be designed by, and installed in
					 accordance with the specifications determined by, a professional engineer
					 licensed to practice in the State of New York. Such sheeting and shoring shall
					 be designed to support the vertical load imposed by the overhanging material as
					 well as the load imposed by the adjacent ground.
(f) Excavated material and other superimposed
					 loads shall be placed at least 24 inches back from the edges of any open
					 excavation and shall be so placed or piled that no part thereof can slide, fall
					 or roll into the excavation. Such 24-inch required clearance may be reduced if
					 the employer installs a barrier or similar retaining device which is designed
					 and constructed to prevent excavated material from falling into the excavation.
TABLE I
STEEPEST ALLOWABLE UNBRACED SLOPES
Depth of
								  Excavation
Type of Soil or
								  Rock
5 to 10 ft.
Over 10 ft.
Stiff cohesive soil
11/2 vertical on 1 horizontal
1 vertical on 1 horizontal (trench) 1 1/2 vertical
								  on 1 horizontal (area)
Noncohesive soil
1 vertical on 1 horizontal 1 vertical on 1 1/2
								  horizontal (when subject to vibrations)
1 vertical on 1 horizontal 1 vertical on 1 1/2
								  horizontal (when subject to vibrations)
Soft cohesive or wet flowing soil
1 vertical on 1 horizontal 1 vertical on 11/2
								  horizontal (when subject to vibrations)
1 vertical on 11/2 horizontal (trench) 1 vertical
								  on 1 horizontal (area) 1 vertical on 1 1/2 horizontal (when subject to
								  vibrations)
Stable rock
Vertical sides permitted
Vertical sides permitted
Unstable rock
11/2 vertical on 1 horizontal
11/2 vertical on 1 horizontal
Notes:
The slopes given in Table I are
						the steepest allowable. Conditions may occur requiring the use of flatter
						slopes to prevent slope failure and subsidence of adjacent areas. A slope shall
						start from the bottom of each side of an excavation or where the lower portions
						of such sides consist of stable rock from the top of such rock.
(g) All sides or banks, slopes and
					 areas in and adjacent to any excavation shall be stripped and cleared of loose
					 rock or any other material which may slide, fall, roll or be pushed upon any
					 person located in such excavation.
(h) Any open excavation adjacent to a
					 sidewalk, street, highway or other area lawfully frequented by any person shall
					 be effectively guarded. Such guarding shall consist of a substantial fence or
					 barricade. As an alternative, such guarding may consist of an extension of the
					 sheeting above the ground surface adjacent to the excavation to a height of at
					 least 42 inches above such adjacent street, highway or other area lawfully
					 frequented by any person. In lieu of such guarding, protection may be afforded
					 by a substantial covering installed over such excavation. Such covering shall
					 consist of planking at least two inches thick full size, properly supported
					 exterior grade plywood at least three-quarters inch thick or material of
					 equivalent strength. Where it is possible that the movement of vehicles or
					 other heavy equipment will take place over such covering, the covering shall be
					 of sufficient strength to withstand such loading without structural failure of
					 the covering or of the support system.
(i) Where no work is being performed in an
					 unattended open excavation which has substantially vertical sides or banks
					 three feet or more in depth, such excavation shall be effectively guarded on
					 all open sides regardless of the location of such excavation. Such guarding
					 shall consist of a fence, a barricade or a safety railing constructed and
					 installed in compliance with this Part (rule). As an alternative, such guarding
					 may consist of an extension of the sheeting above the excavation to a height of
					 at least 42 inches above the adjacent ground, grade or equivalent level. In
					 lieu of such guarding, protection may be afforded by a substantial covering
					 installed over the excavation. Such covering shall consist of planking at least
					 two inches thick full size, properly supported exterior grade plywood at least
					 three-quarters inch thick or material of equivalent strength. Where it is
					 possible that the movement of vehicles or other heavy equipment will take place
					 over such covering, the covering shall be of sufficient strength to withstand
					 such loading without structural failure of the covering or of the support
					 system.
(j) Temporary sheet piling
					 installed in an excavation to permit the construction of a retaining or
					 structural wall shall be left in place until such wall has developed adequate
					 strength to support any load intended to be imposed upon such wall.
(k) Persons shall not be suffered or
					 permitted to work in any area where they may be struck or endangered by any
					 excavation equipment or by any material being dislodged by or falling from such
					 equipment.
(l) The sides of any
					 excavation in stable rock may be vertical and are not required to be provided
					 with sheeting and shoring. Such sides shall be scaled and kept free of all
					 loose rock or material that may be dislodged or may fall into such
					 excavation.