ASDIP Concrete – Concrete Columns Design

ASDIP Concrete
About ASDIP Concrete:   Overview | Benefits | Features | Documentation
Modules:   Concrete Columns Design | Concrete Beams Design | Bearing Walls Design

 
 
Columns are structural compression members which transmit loads from the upper floors to the lower levels and then to the soil through the foundations. Since columns are compression elements, failure of one column in a critical location can cause the progressive collapse of adjoining floors, and in turn, even the collapse of the entire structure. Failure in concrete columns could occur as a result of material failure or by loss of lateral structural stability. If a column fails due to material failure, it is classified as a short column, as opposed to the slender column whose failure is by buckling.

The program performs the design of a circular or rectangular concrete column when subjected to a combination of bending moments and axial loading, based on the latest ACI design criteria and the Ultimate Strength Design Method. It calculates the magnified moments due to slenderness and generates the capacity axial-moment interaction diagram.

ASDIP Concrete - Column GeometryInput Data

The required input data is organized on tabbed pages at the left half of the screen. The column cross section may be either rectangular or circular. The slenderness condition is considered by specifying the effective member length and if the column is sway or non-sway.

The program uses the actual parabolic concrete stress-strain curve, rather than the simplified equivalent rectangular one. The steel considers the strain hardening region.

The loads may be modeled as part of the dead, live, roof live, snow, wind and seismic load cases. If necessary, the moments are internally magnified and the program combines the loads per the specified load combinations.

Example

Design a 22″x22″x 20-ft long square column, which is part of a sway frame in a concrete building. The applied loads are the product of a first-order analysis, as shown.

Find the combined factored amplified moment and axial force and design the reinforcement. Generate the interaction diagram showing the different splicing regions.

 

ASDIP Concrete - Column Example

ASDIP Concrete - Column InteractionOutput

The plate size is adequate since the maximum bearing stress is 65% of the allowable bearing stress for that pier. The plate thickness required is 1″ and the rod embedment length is 12″ with additional reinforcement. The combined tension-shear stress for the anchor rods is 97% of the allowable value, therefore the design is correct.

ASDIP generates a graphical view of the designed base plate and the resulting bearing pressures and anchor rod forces, as shown.

Concrete Column Magnified Moments

 

 

 

 

 

 

 

 

About ASDIP Concrete:   Overview | Benefits | Features | Documentation
Modules:   Concrete Columns Design | Concrete Beams Design | Bearing Walls Design