OSHA Section 1926.652 Excavations Flashcards

Questions and Answers

What does Type A soil include?

Granular cohesionless soils like gravel and sand

Stable submerged soils

Cohesive soils with an unconfined compressive strength of 1.5 tsf or greater (correct)

Previously disturbed soils

No soil is classified as Type A if fissured.

True

What is the unconfined compressive strength range for Type B soil?

Greater than 0.5 tsf but less than 1.5 tsf

Type C soil has an unconfined compressive strength of _____ tsf or less.

0.5 Signup and view all the answers

Which of the following soils can be classified as Type C?

All of the above Signup and view all the answers

Match the soil type with its characteristics.

Type A = Cohesive soils with a strength of 1.5 tsf or greater Type B = Cohesive soil between 0.5 tsf and 1.5 tsf Type C = Cohesive soil with a strength of 0.5 tsf or less Type D = Granular soils like sand and gravel Signup and view all the answers

Granular cohesionless soils can be classified as Type B.

True Signup and view all the answers

What manual tests are used to analyze soil properties?

Plasticity, Dry Strength, Thumb presentation, Other strength test, Drying test Signup and view all the answers

Study Notes

Soil Classification - Section 1926.652 - Subpart P - Appendix A

Type A Soil: Cohesive soils with unconfined compressive strength of 1.5 tsf (144 kPa) or greater.
Examples of Type A: Clay, silty clay, sandy clay, clay loam, cemented soils (e.g., caliche, hardpan).
Exclusions for Type A:
- Fissured soils
- Soils affected by heavy traffic vibrations
- Previously disturbed soils
- Sloped layered systems with steep angles (≥ 4H:1V)
- Materials classified as less stable.

Soil Classification - Type B

Type B Soil: Cohesive soils with compressive strength between 0.5 tsf (48 kPa) and 1.5 tsf (144 kPa).
Includes: Granular cohesionless soils (e.g., angular gravel, silt, sandy loam).
Exclusions for Type B:
- Fissured soils meeting Type A criteria but disturbed
- Dry, unstable rocks
- Sloped systems with less steep angles (< 4H:1V).

Soil Classification - Type C

Type C Soil: Cohesive soils with compressive strength of 0.5 tsf (48 kPa) or less.
Includes: Granular soils (e.g., gravel, sand), submerged soils, and submerged unstable rocks.
Special Conditions: Sloped layered systems with steep angles (≥ 4H:1V) also classified as Type C.

Acceptable Visual and Manual Tests

Visual Tests:
- Analyze excavation samples for particle size and composition.
- Cohesive soils form clumps; granular soils do not.
- Inspect for cracks indicating fissured material and observe soil movement.
- Check for utilities and previous disturbances near excavation sites.
Manual Tests:
- Assess properties like plasticity, dry strength, and perform thumb penetration tests.
- Conduct additional strength and drying tests for a comprehensive soil analysis.

Description

Test your knowledge on OSHA Section 1926.652 related to soil classification for excavations. This flashcard set covers key definitions, types of soils, and their characteristics, specifically focusing on Type A cohesive soils. Perfect for those studying construction safety and regulations.