Prefabricated components are designed to be exceptionally slender, aiming to reduce weight, maximise material efficiency, and enhance the overall aesthetic of buildings. However, a critical question arises: how can we ensure the stability of slender precast reinforced concrete (RC) columns, while maintaining both economic feasibility and safety in the design?

The answer is that it can be approached in several ways: One could engage in manual, albeit laborious, calculations or employ simpler tools like Excel spreadsheets. A more efficient alternative is IDEA StatiCa Member, a software that has been designed to streamline these calculations.

What is IDEA StatiCa Member?

IDEA StatiCa Member is a sophisticated software application developed to address stability challenges in steel and concrete substructures.

It facilitates easy modelling of the structural system, application of all relevant loads, reinforcement design, and immediate execution of analyses and checks. It could also extracts these sub-structures from a global analysis software under equilibrium and transforms them into detailed models with precise boundary conditions. 

More importantly, IDEA StatiCa Member incorporates advanced analytical methods that were traditionally limited to academic research. These methodologies are now streamlined, allowing structural engineers to apply them within realistic time frames, transforming complex analyses from a lengthy process to a more manageable task.

Code limitations for the design of slender columns

Designing slender columns, referred to as 'compression-members' in Eurocode terminology, is inherently complex. Factors such as imperfections and second-order effects significantly influence design internal forces and must be accurately considered to ensure structural safety and efficiency.

The process of defining slenderness limits and adhering to code provisions for slender members involves numerous assumptions, including determining effective length based on structural behaviour and the stiffness and position of lateral supports. The application of calculated imperfections, particularly in biaxial bending, adds to this complexity.

Eurocode provision §5.7.(5) recognises these challenges and permits the use of advanced non-linear design methods for slender members where second-order effects are significant.

IDEA StatiCa Member to the rescue

To circumvent the limitations and conservative approaches often necessitated by code, IDEA StatiCa Member leverages the general design method specified in §5.8.6. This method includes a geometrically non-linear analysis that incorporates second-order effects. Material non-linearity is addressed through stress-strain material laws based on design values.

IDEA StatiCa Member ensures accurate boundary conditions by considering laterally supporting members, their loads, and internal forces. This comprehensive approach fulfills the code's requirements for equilibrium and strain compatibility.

Using IDEA StatiCa Member, engineers can efficiently determine buckling lengths through a Linear Bifurcation Analysis (LBA), easily initiated with a single click.

The critical buckling length is identified and amplified according to code values, followed by a GMNIA analysis that includes geometric non-linearities. Upon completion, the software conducts detailed concrete and reinforcement checks at each section of the member under the amplified internal forces, presenting results comprehensively, allowing engineers to identify and address critical areas effectively.


With IDEA StatiCa Member, engineers no longer need to default to conservative designs when dealing with slender elements. This tool empowers designers to maximize the potential of their reinforced concrete structures through a streamlined and efficient workflow.

Its compatibility with popular global analysis software (like SAP2000, Robot, SCIA Engineer, AxisVM, etc) enhances its utility, allowing for the seamless integration and updating of designs in response to changes in the global analysis model. IDEA StatiCa Member represents a significant step forward in the optimization of slender column design.

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