How to solve challenges when designing a steel to concrete connection

It’s fair to say, steel to concrete connection detailing is a tricky business in the construction industry. All too often multiple methods are needed to design the different elements in a single connection which increases the time taken for the connection’s design, in turn, affecting the Engineer’s productivity.

So, where do these challenges stem from, and how do we solve them? We discuss…

This might seem out-of-date in a world full of complex designs, BIM and integrated software, but these are the findings of a recent survey conducted in association with New Civil Engineer into connections and fixings. We spoke to 100 practising Civil Engineers to consider how they design steel to concrete connections and the findings are eye opening. 

But, why is all this so important? Well, correctly designing this type of connection is a safety critical part of a Civil Engineer’s role in design and construction. Whether it’s bridges or buildings, ensuring an effective and durable connection between steel and concrete is a crucial consideration for any Design Engineer. 

Firstly, disrupted workflow is seen a constant challenge as only 6% said they used a single software to design the connection. For example, when it came to how the different elements – the anchor, baseplate, welds and stiffeners – were designed, almost 60% of people said they rely on a combination of different software types, hand calculations and technical guidelines and approvals.

One respondent to the survey highlighted that the “the lack of a single comprehensive piece of software to cover the design of connections in general (and steel to concrete in particular) makes the whole process complicated”.

For instance, often reactions must be extracted from an FEA [finite element analysis] model and then two to three different methods need to be used to complete the design and engineers tend to use two different pieces of software to manage this but often have to supplement the outputs with hand calculations.

Alongside a disrupted workflow, there is the time-consuming aspect of using various software types. We found that although 45% of people said designing the connection took less than two hours, 33% of people said it took them two to four hours and more worryingly, 11% said it took between four and eight hours, and 10% said it took over eight hours making this is critical concern. Having to carry out various design checks either manually or with different software results in a large effort – very time-consuming.

Another respondent emphasised “we need a design software to speed the design work”.

This is reiterated by our Hilti Product Manager for Technical Ssoftware, Carlos Taborda, who says that the lack of integrated software was holding engineers back.

Carlos said, “This need to use lots of methods to split up the connection means that there is not one reliable source to do the calculations and the change from one source to another affects their productivity”

Let’s not forget about the overall optimisation of the connection, another aspect to the lack of integration. Around 30% specifically said optimisation was ‘difficult and time-consuming with little time for iterations.’ Whilst another 43% said that optimisation together with modelling connections with stiffeners and welds in finite element analysis took too much time and the baseplate rigidity was difficult to check.

There is clearly a problem here, so much so that a whopping 79% of respondents said they would like an integrated design software and that’s where PROFIS Engineering comes in. 

PROFIS Engineering goes beyond anchor design. It handles calculations and analysis of the different elements of a steel to concrete connection including base material, steel plate, anchors, weld and stiffeners with easy iteration and thorough documentation - all from one cloud-based tool.

PROFIS allows the design of steel to concrete connections as a whole with inbuilt checks for steel baseplate rigidity – addressing the issues in the survey.