Selecting a Shoring System
| Shoring Systems actually preload the trench walls and provide a positive restraint to soil movement. Some of the advantages would include: | Shielding Systems are not designed to prevent trench wall collapse, but serve instead to “shield” the workers within the shielding system itself. Some of the advantages would include: | |||
|
|
|||
|
Information to know when ordering: |
||||
|
|
||||
|
Facts: Excavations over 4 feet deep or in unstable soil must be shored according to WISHA. OSHA standard is 5’ deep. Excavation of material may extend 2 feet below the bottom of a shield only if the shield is designed for the full depth of the trench and there is no evidence of soil loss from below the bottom of the shield. WISHA/OSHA allows the use of 1 1/8” plywood or 3/4” Finform sheeting in conjunction with hydraulic shoring. Vertical shoring can be used in C60 soil type when the manufacturers tabulated date allows for it. Pre-engineered shoring systems can be used in trenches over 20’ deep when the manufacturers tabulated data allows for it.
|
||||
|
Definitions: |
||||
| Tabulated Data: | Competent Person: | Soil Classification: |
|
Tables and charts approved by a registered professional engineer. These tables and charts provide information on the shoring capabilities. |
One who is capable of identifying predictable hazards and who has the authority to take corrective measures to eliminate them. |
Method of classifying soils based on environmental conditions. This must be completed by the competent person. |
|
Type A: Cohesive soils with an unconfined compressive strength of 1.5 TSF or greater. Examples would be dry stable material such as clay, silty clay loam, and cemented soils.Type B: Cohesive soil with an unconfined compressive strength of 0.5 TSF, but less than 1.5 TSF. Examples would be dry to moist soils, clays, and gravels.Type C: Cohesive soil with an unconfined compressive strength of 0.5 TSF or less. Examples would be some granular or submerged soils. |
||
