Watch & Learn RKALC Apps

Latest on RKALC

GreenKALC is Out!

Our latest webapp, The GreenKALC, is out
This is a unique piece of work enables you calculate the carbon footprint of your building. There are tables breaking down the building into sections, this makes it easy for you to fill in, and choose the right material to reduce cradle to gate emissions.

Visit the Q&A Page

Welcome to our Q&A Page!
This is the space for structural engineers to ask questions and answer others. We have added many questions for our members to share knowledge and trigger more discussions in the public. We are receiving questions and thought some might be shared to spread the knowledge

RKALC Structrual Engineering Apps

RC Calculator

Learn all there is to know about the concrete calculator, specially crafted for the Australian Standard AS3600-2018. This application is made to help expedite the process without compromising accuracy.

Access RC Calculator »

STM Calculator

This is an absolutely amazing application, will help you rapidly design transfer beams / walls, using the strut-and-tie method to AS3600-2018. You can see how it generates state-of-art output in no time.

Access STM Calculator »

Steel Calculator

The steel calculator is here! Say goodbye to paper catalogues or giant PDF files to find the properties and capacities of steel sections. This is a true time saver, made for the standard Australian sections

Access Steel Calculator »

Analysis Verifier

This is all what you need for continuous beams / slabs in real life, or if you are working with a sophisticated software and need to get a feel of what it is doing! A great tool to verify software results, and a little bit more

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This is our new web that you will need to calculate tributary areas with graphical representation, only thing to do is to open pdf file of floor plan, and trace around slab edge, columns, and walls, click analyse (on the brain icon) to see magic.

Access TribKALC »


This is our unique webapp that you will need to calculate Centres of Mass and Rigidity with graphical representation, only thing to do is to open pdf file of floor plan, and trace around slab edge, and walls, click analyse (on the brain icon) to see magic.

Access CentresKALC »


This is our unique webapp comes with dynamic and easy to use graphics pad. It is waht you will need to estimate pile group reactions to vertical and lateral loads. Super fast and easy to use similar to its sister apps, TribKALC and CentresKALC.

Access PileGroupKALC »


This is our latest webapp for the design of masonry walls to the Australian Standard AS3700-2018. Your can design walls made of clay bricks, concrete, light weight concrete, and calcium silicate. Design for axial, bending, shear, and fire

Access MasonryKALC »

Welcome to RKALC Blog

The Tale of Two Building Developers:

Navigating Urban Landscapes Through Architecture and Structural Engineering

This article is inspired by Bill Baker's address to DTU University in 2015. You can watch the address here.

Iris Bay Dubai

The architecture, is the story of space and time, it is about fashion, colors, natural light, and nice views. It is also about a fresh breath of green and positive interfacing with the community, all of which pour in pride of owning an apartment in a landmark building.

On the other hand, structural engineering is the language of architecture; it is the words or vocabulary through which architecture is written. Some of this "vocabulary" is quite eloquent and makes a powerful impact, as seen in the Sydney Opera House here in Sydney, or the Burj Dubai. Others stumble, like those rectangular apartment buildings we see everywhere, the majority of which are designed by nothing but greed. I am not quite sure if there is ever architecture in those other than complying dimensions or sometimes performance solutions. I only see rectangles stacking next to each other, above each other, to form giant rectangles, or sometimes trapezoids when the land has such shape.

Let us face it, there is a huge need to grow, and a great demand by our communities to expand and aspire. At the same time, we live in a world of limited resources and increasing awareness of human's footprint on the environment and nature. That said, can we not agree on common grounds? And when I say "we," I mean us in the built environment, the architects with the developers at their back, and the structural engineers, the deliverers of the whole vision.

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Peter Rice - An Engineer Imagines!

Although I’ve been in the business of structural engineering for over two decades, and despite being a chartered member of IStructE, a UK accreditation body, I only knew about the Irish Structural Engineer, Peter Rice, a few years ago! I said to myself, alas! What am I doing? This rush in doing work and attempting to be up to speed with industry commitments made me miss great things… This dilemma of balancing between acquiring knowledge while servicing clients and employers keeps coming up along the way, and whenever I meet a great mentor or know about an inventive piece of work.

Euler Load Image 1

I remember experiencing similar feelings early on when I knew about Nervi, Fazlur Rahman Khan, Ove Arup, Frei Otto, and even some of the living superstars like Bill Baker and Robert Sinn, however, Peter Rice struck me the most!

For those who don’t know him, it can be safely said that he was, and still, one of the greatest minds in structural engineering, a true thinker and compassionate human being who invented so many beautiful things that we take for granted.

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To FEA or Not to Be!

It would be good to start these reflections with the following quotes (Wilson, Jan 2002):

[My freshman Physics instructor dogmatically warned the class "do not use an equation you cannot derive". The same instructor once stated that "if a person had five minutes to solve a problem, that their life depended upon, the individual should spend three minutes reading and clearly understanding the problem"..."With respect to modern structural engineering, one can restate these remarks as "do not use a structural analysis program unless you fully understand the theory and approximations used within the program"]

It has been quite a while since starting my career; through which, I have attempted, or more precisely, life has taken me across a number of challenges, in a pursuit for engineering excellence that I hope would be reached one day. One of these dares is trying to track, or maybe confirm, the actual development in structural engineering, in light of the astronomical advancement of #CAD / #FEA and debate of responsibly deploying them. A debate usually witnessed among young and “older” professionals.

Let us imagine a journey in time, no farther than the late 1970’s; maybe similar discussions on the analysis and design aids were, as well, very much on the table. .

Euler Load Image 1
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Reinforced Concrete Columns

Designing columns is possibly the most repetitive task structural engineers undertake in their daily routine. When we have a column subject to combined axial and bending, one might ask the following questions:

  • How slender is this column?
    Slenderness of any column is the single most important parameter we should determine at the beginning of the design task. As a rule of thumb, if the column is braced, then a height to width ratio (or slenderness) under 15 should make an axially loaded column fail at a loading nearing the squash load, i.e., the capacity of the section. Whereas in unbraced floors, the height to width ratio should not be any greater than 10; otherwise, failure will happen quickly on buckling way before the section capacity is suffering.

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    The Strut and Tie Method

    STM is a very efficient and simple way to represent the stress flow within a concrete element or parts of it that are under the D region category, where Bernoulli assumptions are not applicable. Some say that the use of this method goes back to the early 20th century, yes, some 120 years ago when concrete was a new thing, and engineers used to rely on their intuition and expectation of load path.

    STM was given several boosts between the sixties and early eighties when Schlaich et al. published guidance on the theory and given typical examples with load paths. Later, international codes started to implement and “regulate” it if you wish, to keep up with engineers, who always challenge the status quo.

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    Coupled Shear Walls

    First things first, as you read this post, please refer to Coupled Shear Wall calculator available at: See Link

    The issue of coupled shear walls is one of the most debated topics among structural engineers. It's not surprising to see five people with twenty different opinions, each of valid points. Ove #Arup once said on this:

    "The more you look, the more you see,
    And that's why experts disagree.
    For some look here, and some look there,
    But no one can look everywhere.
    For if they did, it seems to me
    That they would hardly be experts, you see.
    According to their point of view,
    What they say may well be true,
    But looking from another angle,
    We tend to get into a tangle.
    Which of the views is then correct?
    That is not easy to suspect.”

    Euler Load Image 1
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    To Double Curvature or Not?

    Clause 10.3.1 of the Australian Standard AS3600-2018 includes a very interesting stipulation on columns in relation to the ratio of M1/M2. This applies to normal columns found throughout the building height, which are typically subject to double curvature behaviors.
    According to the Standard, if the analysis moment is less than the minimum eccentricity moment about the respective direction or 5%DN*, the ratio above should be taken as negative. This means the column should be assumed to be subject to single curvature, making it more conservative due to the high moment magnifier (δb).
    The logic behind this stipulation is that there may be inaccuracies or errors during installation or due to pattern loading. As a result, the column might experience single curvature loading or "snap through to single curvature mode," as stated in AS3600. Therefore, the analysis assuming double curvature moments would be overwritten by the opposite minimum eccentricity moment.

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