Page 35 - Pipeline Rules of Thumb Handbook

22 Pipeline Rules of Thumb Handbook

Trench jacks may be used in lieu of, or in combination with cross braces. Shoring is not required in solid rock, hard shale, or hard slag. Where

Maximum Spacing Horizontal Feet 6 6 6 6 6 6 6 6 6 6

Vertical Feet 4 4 4 4 4 4 4 4 4 4

12 to 15 Feet Inches 8 ¥ 6 6 8 ¥ 6 6 8 ¥ 8 8 8 ¥ 8 8 8 ¥ 8 8 8 ¥ 8 8 10 ¥ 8 8 10 ¥ 8 8 10 10 ¥ 8 12 10 ¥ 10

Size & Spacing of Members Cross Braces Width of Trench 9 to 12 6 to 9 3 to 6 Feet Feet Feet Inches Inches ¥ 6 6 ¥ 4 4 ¥ ¥ 6 6 ¥ 4 4 ¥ ¥ 6 6 ¥ 6 6 ¥ ¥ 6 6 ¥ 6 6 ¥ ¥ 6 6 ¥ 6 6 ¥ ¥ 6 6 ¥ 6 6 ¥ ¥ 8 8 ¥ 6 6 ¥ ¥ 8 8 ¥ 6 6 ¥ ¥ 8 8 ¥ 8 8 10 ¥ 10 ¥ 8 8

desirable, steel sheet piling and bracing of equal strength may be substituted for wood.
Up to 3 Feet Inches Inches 4 6 ¥ 2 4 6 ¥ 2 4 4 ¥ 4 4 4 ¥ 4 4 4 ¥ 4 6 6 ¥ 4 6 6 ¥ 4 6 6 4 ¥ 6 ¥ 12 4 ¥ 6 ¥ 12 ¥ 4

Maximum Spacing Feet — 4 4 4 4 4 4 4 4 4

Stringers

Minimum Dimensions Inches — 6 ¥ 4 6 4 ¥ 6 4 ¥ 6 ¥ 4 4 ¥ 4 6 4 ¥ 10 8 ¥ 12 4 ¥ 8 6 ¥

Maximum Spacing Feet 6 3 Close Sheeting Close Sheeting 4 2 Close Sheeting Close Sheeting Close Sheeting Close Sheeting
Trench shoring—minimum requirements
Uprights 6 6 6 6 6 6 6

Minimum Dimensions Inches 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 4 3 ¥ or 2 ¥ 6 3 ¥ 6 3 ¥ 6 3 ¥

Kind Or Condition of Earth Hard, compact Likely to crack Soft, sandy, or filled Hydrostatic pressure Hard Likely to crack Soft, sandy, or filled Hydrostatic pressure All kinds or conditions All kinds or conditions

Feet
Feet 5 to 10 10 to 15 15 to 20 Over 20
Trench
Depth of