ASDIP Concrete – Bearing Walls Design

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

 
 
Bearing walls are structural compression members which also may resist out-of-plane lateral loads. The resulting moments are referred to as weak-axis bending. A tilt-up wall panel exposed to wind is an example of this type of wall. Per ACI, bearing walls may be designed as compression members using the strength design provisions for flexure and axial loads, like columns. Any wall may be designed by this method and no minimum wall thicknesses are prescribed. As with columns, the design of walls is difficult without the use of design aids. Wall design is further complicated by the fact that slenderness is a consideration in practically all cases. The ACI Moment Magnification method is generally used to account for the slenderness effects.

The program performs the design of a concrete bearing wall when subjected to a combination of weak-axis 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. A multi-story wall may also be modeled.

Concrete Bearing Wall GeometryInput Data

The required input data is organized on tabbed pages at the left half of the screen. The wall section is rectangular with either one or two courtains of reinforcement. A parapet may be specified, or the wall may be continuous at top. In this latter case, the load from the upper floor is accounted for by setting the uniform load eccentricity as zero.

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 and wind load cases. If necessary, the moments are internally magnified and the program combines the loads per the specified load combinations.

Example

Design a 6.5″-thick tilt-up wall panel that supports a 18′-high double-T roof in a retail building. The wall has a 2′-high parapet and is exposed to wind and gravity loads, as shown.

Find the combined factored amplified moment and axial force, and design the reinforcement. Generate the wall strength interaction diagram.

 

Concrete Bearing Wall Example

Bearing Wall InteractionOutput

The output results are organized on tabbed pages at the right half of the screen. The program calculates the magnified moments and axial loads for all the specified load combinations. Then the capacity interaction diagram is accurately calculated based on the geometry and reinforcement.

The moment magnification process is detailed and reported, as shown, for a granular check of the design. The values that fail the design criteria are highlighted in red for easy identification.

Concrete Bearing Wall Magnified Moments

 

 

 

 

 

 

 

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