What is needed for a 9’ deep trench in type c soil

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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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Oregon Administrative Rules Oregon Occupational Safety and Health Division ## ALUMINUM HYDRAULIC SHORING FOR TRENCHES ## (f) Example to Illustrate the Use of the Tables: ## (1) Example 1: A trench dug in Type A soil is 6 feet deep and 3 feet wide. From Table D-1.1: Find vertical shores and 2 inch diameter cylinders spaced 8 feet on center (o.c.) horizontally and 4 feet on center (o.c.) vertically. (See Figures 1 & 3 for typical installations.) ## (2) Example 2: A trench is dug in Type B soil that does not require sheeting, 13 feet deep and 5 feet wide. From Table D-1.2: Find vertical shores and 2 inch diameter cylinders spaced 6.5 feet o.c. horizontally and 4 feet o.c. vertically. (See Figures 1 & 3 for typical installations.) - (3) A trench is dug in Type B soil that does not require sheeting, but does experience some minor raveling of the trench face. The trench is 16 feet deep and 9 feet wide. From Table D-1.2: Find vertical shores and 2 inch diameter cylinder (with special oversleeves as designated by footnote #2) spaced 5.5 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. 3x12 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…

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## SLOPING &amp; BENCHING ## B-1.3 Excavations made in Type C Soil. - 1. All simple slope excavations 20 feet or less in depth shall have a maximum allowable slope of 1 1/2 :1. - 2. All excavations 20 feet or less in depth which have vertically sided lower portions shall be shielded or supported to a height at least 18 inches above the top of the vertical side. All such excavations shall have a maximum allowable slope of 1 1/2:1. - 3. All other sloped excavations shall be in accordance with the other options permitted in §1926.652(b). Simple Slope <!-- image --> Vertical Sided Lower Portion <!-- image -->

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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…

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## OCCUPATIONAL HEALTH AND SAFETY, 2020 S-15.1 REG 10 - (6) If a worker is required to enter a trench, an employer or contractor shall: - (a) install ladders, stairways or ramps to provide a safe means of entrance to and exit from the trench; and - (b) ensure that the ladder, stairway or ramp is located not more than 8 metres from a worker working in the trench. - (7) An employer or contractor shall ensure that workers are instructed in and comply with the requirements of this section. 31 Dec 2020 c S-15.1 Reg 10 s17-7. ## Excavated shafts and tunnels - 17-8 (1) An employer or contractor shall ensure that: - (a) during excavating, the walls of an excavated shaft or tunnel are retained by temporary protective structures that are adequate: - (i) for the type of soil; and - (ii) to prevent collapse or cave-in of the walls of the excavated shaft or tunnel; - (b) during the excavating of an excavated shaft that is 3 metres or more deep or of a tunnel, the walls of the shaft or tunnel are retained by temporary protective structures designed and certified by a professional engineer to be adequate for the protection of workers in the shaft or tunnel and constructed, installed, used, maintained and dismantled in accordance with that design; - (c) a solid or wire mesh fence at least 1 metre high, or other equally effective means of preventing material from falling into an excavated shaft or the surface opening of a tunnel, is provided around that shaft or opening; and - (d) substantial gates that are not less than 1 metre high are installed in every opening in a fence provided pursuant to clause (c) and the gates are kept closed except when being used. - (2) A worker who opens a gate mentioned in clause (1) (d) shall close the gate after the worker no longer has a need to keep the gate open. - (3) An employer or contractor shall provide suitable equipment to keep a tunnel or excavated shaft free from any accumulation of water. 31 Dec 2020 c S-15.1 Reg 10 s17-8. ## Bor…

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## 29 CFR 1926 (OSHA) - (2) Manual tests. Manual analysis of soil samples is conducted to determine quantitative as well as qualitative properties of soil and to provide more information in order to classify soil properly. - (i) Plasticity. Mold a moist or wet sample of soil into a ball and attempt to roll it into threads as thin as Ú 1 8 -inch in diameter. Cohesive material can be successfully rolled into threads without crumbling. For example, if at least a two inch (50 mm) length of Ú -inch thread can be held on one end without tearing, 1 8 the soil is cohesive. - (ii) Dry strength. If the soil is dry and crumbles on its own or with moderate pressure into individual grains or fine powder, it is granular (any combination of gravel, sand, or silt). If the soil is dry and falls into clumps which break up into smaller clumps, but the smaller clumps can only be broken up with difficulty, it may be clay in any combination with gravel, sand or silt. If the dry soil breaks into clumps which do not break up into small clumps and which can only be broken with difficulty, and there is no visual indication the soil is fissured, the soil may be considered unfissured. - (iii) Thumb penetration. The thumb penetration test can be used to estimate the unconfined compressive strength of cohesive soils. (This test is based on the thumb penetration test described in American Society for Testing and Materials (ASTM) Standard designation D2488-'Standard Recommended Practice for Description of Soils (Visual-Manual Procedure).') Type A soils with an unconfined compressive strength of 1.5 tsf can be readily indented by the thumb; however, they can be penetrated by the thumb only with very great effort. Type C soils with an unconfined compressive strength of 0.5 tsf can be easily penetrated several inches by the thumb, and can be molded by light finger pressure. This test should be conducted on an undisturbed soil sample, such as a large clump of spoil, as soon as practicable after ex…