How wide should my trench be if it is 8ft deep?

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feet o.c. horizontally and 4 feet o.c. vertically, plywood (per footnote (g)(7) to the D-1 Table) should be used behind the shores. (See Figures 2 & 3 for typical installations.) - (4) Example 4: A trench is dug in previously disturbed Type B soil, with characteristics of a Type C soil, and will require sheeting. The trench is 18 feet deep and 12 feet wide. 8 foot horizontal spacing between cylinders is desired for working space. From Table D-1.3: Find horizontal wale with a section modulus of 14.0 spaced at 4 feet o.c. vertically and 3 inch diameter cylinder spaced at 9 feet maximum o.c. horizontally. 3 × 12 timber sheeting is required at close spacing vertically. (See Figure 4 for typical installation.) - (5) Example 5: A trench is dug in Type C soil, 9 feet deep and 4 feet wide. Horizontal cylinder spacing in excess of 6 feet is desired for working space. From Table D-1.4: Find horizontal wale with a section modulus of 7.0 and 2 inch diameter cylinders spaced at 6.5 feet o.c. horizontally. Or, find horizontal wale with a 14.0 section modulus and 3 inch diameter cylinder spaced at 10 feet o.c. horizontally. Both wales are spaced 4 feet o.c. vertically. 3 × 12 timber sheeting is required at close spacing vertically. (See Figure 4 for typical installation.) - (g) Footnotes, and general notes, for Tables D-1.1, D-1.2, D-1.3, and D-1.4. - (1) For applications other than those listed in the tables, refer to §1926.652(c)(2) for use of manufacturer's tabulated data. For trench depths in excess of 20 feet, refer to §1926.652(c)(2) and §1926.652(c)(3). - (2) 2 inch diameter cylinders, at this width, shall have structural steel tube (3.5 × 3.5 × 0.1875) oversleeves, or structural oversleeves of manufacturer's specification, extending the full, collapsed length. - (3) Hydraulic cylinders capacities. (i) 2 inch cylinders shall be a minimum 2-inch inside diameter with a safe working capacity of not less than 18,000 pounds axial compressive load at maximum extension. Maxim…

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## S-15.1 REG 10 ## OCCUPATIONAL HEALTH AND SAFETY, 2020 - (d) an excavation or trench that a worker may be required or permitted to enter is kept free from any accumulation of water; and - (e) the slope of a spoil pile adjacent to an excavation or trench has a slope at an angle not steeper than 1 horizontal to 1 vertical, or 45 measured from ° the horizontal. - (2) Subject to subsections (3) and (4), if a wall of an excavation or trench is cut back, an employer or contractor shall ensure that: - (a) in the case of type 1 or type 2 soil, the walls are sloped to within 1.2 metres of the bottom of the excavation or trench, with a slope at an angle not steeper than 1 horizontal to 1 vertical, or 45 measured from the horizontal; ° - (b) in the case of type 3 soil, the walls are sloped from the bottom of the excavation or trench, with a slope at an angle not steeper than 1 horizontal to 1 vertical, or 45 measured from the horizontal; and ° - (c) in the case of type 4 soil, the walls are sloped from the bottom of the excavation or trench, with a slope at an angle not steeper than 3 horizontal to 1 vertical, or 19 measured from the horizontal. ° - (3) If an excavation or trench contains more than 1 type of soil, the soil must be classified as the soil type with the highest number. - (4) Subsection (2) does not apply to an excavation or trench that is cut in sound and stable rock. - (5) If an excavation or trench is to be made in the vicinity of an overhead power line, an employer or contractor shall ensure that the work is carried out in a manner that will not reduce the original support provided for any overhead power line pole, unless permission has previously been obtained from the utility company responsible for the overhead power line. - (6) An employer or contractor shall ensure that no powered mobile equipment or vehicle is operated, and that no powered mobile equipment, vehicle or heavy load is located, near an excavation or trench so as to affect the stabili…

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## OCCUPATIONAL HEALTH AND SAFETY, 2020 - (3) An employer or contractor shall ensure that a temporary protective structure in an excavation more than 3 metres deep is designed and certified as safe by a professional engineer and installed, used, maintained and dismantled in accordance with that design. 31 Dec 2020 c S-15.1 Reg 10 s17-6. ## Protection against cave-in of trenches - 17-7 (1) If a worker is present in a trench that is more than 1.2 metres deep, an employer or contractor shall ensure that the worker is protected from cave-ins or sliding material by: - (a) cutting back the upper portion of the walls of the trench in accordance with subsection 17-4(2); - (b) installing a temporary protective structure; or - (c) a combination of cutting back the walls to the slope specified in subsection 17-4(2) and installing a temporary protective structure that extends at least 300 millimetres above the base of the cut-back. - (2) An employer or contractor shall ensure that a temporary protective structure required by clause (1) (b) or (c) is: - (a) designed and installed using shoring made of number 1 structural grade spruce lumber having the dimensions set out in Table 14 of the Appendix for the type of soil and the depth of the trench or made of material of equivalent or greater strength; or - (b) designed by a professional engineer and constructed, installed, used, maintained and dismantled in accordance with that design. - (3) An employer or contractor shall ensure that a temporary protective structure in a trench more than 6 metres deep in type 1, type 2 or type 3 soil or in a trench more than 4 metres deep in type 4 soil is designed and certified as safe by a professional engineer and installed, used, maintained and dismantled in accordance with that design. - (4) An employer or contractor shall ensure that: - (a) shoring is installed and removed in a manner that protects workers from cave-ins and structural collapses and from being struck …

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- (a) cutting back the walls of the excavation to reduce the height of the remaining vertical walls, if any, to no more than 1.5 metres for 'hard and compact soil' and 'likely to crack or crumble soil', - (b) installing temporary protective structures, or - (c) using a combination of the methods in clauses (a) and (b). 450 (2) Subsection (1) does not apply if a trench is constructed in solid rock throughout the entire trench. ## Cutting back walls - 451 If the walls of an excavation are cut back, an employer must ensure that - (a) if the soil is classified as 'hard and compact soil', the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 30 degrees measured from the vertical, - (b) if the soil is classified as 'likely to crack or crumble soil', the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical, and - (c) if the soil is classified as 'soft, sandy or loose soil', the walls are sloped from the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical. ## Loose materials 452 An employer must ensure that loose materials are scaled and trimmed from the sides of an excavation if workers may be on or near the sides. ## Spoil piles - 453 An employer must ensure that a spoil pile is piled so that - (a) the leading edge of the pile is at least 1 metre away from the edge of the excavation, - (b) the slope of a spoil pile adjacent to the excavation is at an angle of not more than 45 degrees from the horizontal, and - (c) loose materials are scaled and trimmed from the spoil pile. ## Power pole support 454 An employer must ensure that work that disturbs the ground in the vicinity of an overhead power line is performed in a manner that does not reduce the original support provided for power line poles. ## Safe entry and exit 455 (1) An employer must ensure that if a worker is required to enter a tren…