Stability and robustness of a structure

[Smitash]

What is meant by stability and robustness of a structure?

From what i have read, stability means maintaining the equilibrium position of a structure even under the action of an external force. Stability must be provided into two orthogonal directions to resist lateral forces such as wind loads, earthquake and horizontal components sue to soil load. Stability can be achieved by providing shear walls, lift shafts and rigid frames. To investigate the stability of a structure, the structure should be analysed with the maximum wind loading and minimum dead.

By robustness, it is meant that all structural members should be tied together to ensure that collapse of a small part of the structure will not cause collapse of the whole structure. This is achieved by using peripheral ties, internal ties, horizontal ties to walls and columns and vertical ties.

What is the difference between the different ties stated above?...thanks

 

[rb1957]

a determinate structure (one that just satisfies the equation of equilibrium, like a beam with a pin support at one end and a roller at the other, satisfies stability but isn't robust.

a robust structure would be indeterminate (hyper-static) because it would have redundant loadpaths (that can fail and the strcuture can still carry the required loads).

don't understand "What is the difference between the different ties stated above?" ... i see ties only mentioned in the robustness description (so why "difference" ?)

Quando Omni Flunkus Moritati

 

[Smitash]

I wanted to know the difference between peripheral ties, internal ties, horizontal and vertical ties..

 

[steellion]

The "tie" concept is used to provide redundancy to the structure to prevent progressive or disproportionate collapse. Ties are generally accomplished with additional concrete reinforcement, but can be other materials as well.

Peripheral tie: continuous chord around perimeter of floor plate
Internal tie: ties around perimeter of slab openings
Horizontal ties: ties across each floor plate
Vertical ties: Continuous vertical ties (columns) for the structure

 

[rb1957]

aren't "ties" just structure that joins two pieces of structure together ? (beit vertically, horizontally, etc ...)

Quando Omni Flunkus Moritati