Deadman Anchor 1

[LOKSTR]

How will you treat a conctre deadman anchor about 2m deep inside the ground (rectangular x-s)support condition for calculating design moments? One conc. force 'P' is pulling the block at the middle.


Will it be treated as simply supported at ends & the moments calculated as PL/4( L is length of block)? or because of soil support over the whole length it should be treated differently?

Any thoughts will be greatly appreciated.

 

[SlideRuleEra]

PL/4 would be conservative. Considering the many variables in dealing with soil this is probably a assumption.

IMHO, a "best case" would be a really rigid block which has the soil loading uniformly distributed over the length of the block. To analyze this, consider half of the block length and perform the calcs as if this half was a cantilever beam - uniformly distributed load. See Beam Diagram #19 in AISC Manual of Steel Construction (9th Ed). Be sure to multiply the results by two, to account for both halves of the block.

(Please note that I am only referring to the diagram itself, not on any kind of AISC way of performing the calcs).

(Also note that if the block is that rigid, it will probably pass the PL/4 test, too).

A middle ground would be to assume "cantilever beam - load increasing uniformly to fixed enc" - ASIC diagram #18.

http://www.SlideRuleEra.net

 

[SlideRuleEra]

Left out a word in the first line - I consider PL/4 a good assumption.

http://www.SlideRuleEra.net