Maximum depth/Span ratio of Cantilever steel beam 5

[ALK2415]

Dear Colleagues
What is the practical depth/Span ratio for a Cantilever beam ?
thinking of overhang Plate girders set that cover 60' long [18.3 meters] and 20' wide [6 meters]
thinking of 1/10 ?
this is kind bizarre, but it a monument kind structure, made for main terminal express welcomed sign

similar to this picture [but unbalanced type]

 

[ALK2415]

@ JLNJ [all structure is steel] except the cladding will be reinforced masonry brick-wall

A little rotation at or of the foundation will cause significant deflections of the cantilever tip

if you noticed what BridgeSmith , did similar foundation

If you have enough room for 2 rows of drilled shaft foundations

: 6 drilled piers with 80 cm diameter [attached to pile cap and also tie beams {short & long directions}]

trying to resolve the support inclination of main Girders [32 Degree]

Main Box girders shown in following sections starting from left

 

[BridgeSmith]

You'll probably need something more substantial (deeper) than what you've shown to connect the front and back columns. You should consider a rectangular or oblong shaft in place of each pair of columns and then connect those directly on top of the 2 drilled shafts below ground. Even then, you may find it difficult to get enough reinforcing into those drilled shafts for the tension, while still maintaining the clearance between bars (5 times the maximum concrete aggregate size).

Rod Smith, P.E., The artist formerly known as HotRod10

 

[ALK2415]

Dear ROD
still working on the FEM Model
the foundations pile cap is not shown on drawings [nor the Girder internal bracing or wall stiffening]
after a while i will present the analysis shown which case of failure [dead-weight or wind] is dominate
the Tie-beams are shown in red [kind of grillage beams that connect all girders to top of each columns longitudinally and transversely]
Any thoughts on the inclined seat (32 degree) ???
Could Anchor cables (in first set of columns) with flat concrete footing be useful here ???

 

[BridgeSmith]

I just wanted to be sure you realized that the spacing requirements for the reinforcing in the drilled shafts (transverse and longitudinal) are significantly larger than for a column, due to the limitations on being able to consolidate (vibrate) the concrete (10' is about as deep as they can go).

Inclined seat can be done. Level or stepped would also work. The connection of the end that will provide enough capacity for the tension (uplift) force will definitely take some careful thought.

after a while i will present the analysis shown which case of failure [dead-weight or wind] is dominate

Typically, it would be dead load + wind, assuming you don't have to contend with ice or snow loading.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[ALK2415]

some updates

and did some modification on geometry
Link
Not final detailing