Excavation Subpart P .650-652 App A&B

Type A

Cohesive 1.5 tsf or more

Clay, silty clay, clay loam

Caliche & hard pan

NOT PREVIOUSLY DISTRIBUTED

Type B

Cohesive more than .5 up to 1.5 tsf

Angular gravel, silt, silty loam, sandy loam

INCLUDES PREVIOUSLY DISTURBED SOIL & type A IF DISTURBED

Type C

Cohesive .5 or less

Gravel, sand, loamy sand, submerged soil, freely seeping water

Sand is type

C

Strength order

A,B,C

Breaking Points

1.5 & .5 tons sq/ft

Who makes clarification

Competent person

Stable rock

Max slope?

Angle?

Vertical

90°

Type A

Max slope?

Angle?

3/4:1

53°

Type B

Max slope?

Angle?

1:1

45°

Type C

1 1/2 : 1

34°

Two Slope Exceptions found?

Below table-b1 pg 345

Deeper than 20ft

Any sloping must be designed by engineer

2ft rule

Spoil piles, materials, equipment stay MIN 2 ft from edge or use retaining device

4ft rule

Trenches 4ft or deeper need way out; stairs, ladder every 25ft in both directions

4ft rule (test)

If hazardous atmosphere exists test before entry when deeper than 4ft of oxygen floor 19.5%

5ft rule

Protective system required at 5ft unless stable rock or no cave in

Daily rule

Competent person inspects excavation site daily before shift after rain storm

Surface Embracements

Removed or supported as necessary to protect employees

Adjacent Structures

Shoring bracing or underpinning where stability is endangered

Inside box 2ft max

Digging below bottom of a support & only if protected by .652 e2 & g2

Inside box 18 in

Min support height above top of the vertical side of type C vertical sides lower portion

Kick out

Accidentally release or failure of a cross brace

Locate utilities when

Before you dig