Features

The precast concrete design expert

19 May , 2022  

There was double delight for Petruf Consulting Structural Engineers recently when it was shortlisted for two awards at the 2021 Irish Construction Industry Awards.

One of Ireland’s most progressive structural engineering consultancy companies and an expert in precast concrete design, Petruf Consulting was nominated in the Designer of the Year and BIM Initiative of the Year categories for its involvement in developments at Townsend Street and Santry in Dublin as well as The Windsor Hotel in Cork. Launched in 2014, the Irish Construction Industry Awards recognise, encourage and celebrate original and innovative contractors, businesses, teams, consultants and projects that demonstrate excellence in the built environment.

“We were delighted to receive two nominations. They reflect well on our work and our team,” says Frank Petruf, who established Petruf Consulting in Newbridge, Co. Kildare in 2009.

Providing structural engineering design services for precast concrete manufacturers all over Ireland, Petruf is at an exciting stage of its development where it is enhancing its role as designer into the role of consulting engineer to help its clients’ complete projects in a better, more effective way with substantial savings. Using its innovative design approach when the project is designed to precast concrete at early stage rather than shortly before construction, savings of about €15,000 per apartment can be achieved. This can lead to total savings of €4.5 million for a project scheme of 300 apartments with underground car parking.

“We approach the structural aspect of a project in an innovative way, with ideas to provide structural model-based designs to support architectural creativity,” Frank explains.

“The aim of our design is to provide our clients with accurate structural calculations, drawings, details, quantity take-off tables and project data readily generated from an interactive 3D model. We offer a cost-effective solution and a reduction to construction period, while considering the buildability of projects onsite. We have a broad range of experience in the commercial, educational, residential, industrial and leisure sectors.”

The benefits of using Petruf Consulting services, together with a complete precast solution for the building structure compared to a traditional consultancy and RC, are many.

Petruf Consulting’s structural engineering and civil design are based on more than 20 years’ experience in the design of multi-storey and high-rise buildings, close cooperation with precast concrete manufacturers across Ireland and state-of-the-art software package to ensure 3D BIM design is compatible with the precast concrete manufacturers. Frank and his team provide a comprehensive design package tailored to precast concrete, including all relevant shop drawings, which leaves the precast supplier with the task of manufacturing and supplying the panels only.

Furthermore, the consultancy provides specialist production drawings to automated factories and CNC files necessary for robots to manufacture precast concrete panels.

Petruf offers an innovative approach to structural design using modern, tried and tested, and efficient techniques that are adaptable to industry changes. In contrast, traditional consultancies are mostly still using outdated, inefficient design methods that do not adapt to modern design techniques required for fast, efficient, off-site construction processes.

With Petruf Consulting, there are few subcontractors involved in the project design as it provides design for steelwork and RC in-situ concrete structures, including shop drawings for steel work and RC drawings for in-situ concrete. Architectural creativity is supported from the project’s early stages. Knowledge and expertise strengthened by technology allows the company to realise any architectural aspect to ensure practicality in production and on-site.

In addition, Petruf guarantees a smoother approval process, less revisions and alterations. All structural and civil engineering design is in-house, so no extra delay is caused by many other design subcontractors affecting the design programme. Experienced and good working relationships built up with all the leading precast concrete manufacturers enables the consultancy to prepare its design in the right format and factory standards to suit any of the precast concrete suppliers at the early project stages.

As stated, the projects for which Petruf Consulting received 2021 Irish Construction Industry Award nominations were Townsend Street and The Windsor Hotel (Designer of the Year) and Santry (BIM Initiative of the Year). Townsend Street is an eight-storey multi-purpose development comprising Travelodge Hotel, Staycity Aparthotel, residential block for Dublin City Council as well as retail and restaurant space at ground floor. Frank provided structural engineering analysis of the precast concrete main cross-walls structure for Blocks 3 and 4, and recon stone beams for Blocks 1, 2 and 3. The main contractor was John Paul Construction.

The project at Swords Road, Santry, Dublin 9 was a mixed-use development consisting of 200 apartments across three seven-storey blocks with basement parking under two or three blocks and retail space at ground floor. Frank and his team provided structural engineering analysis for all blocks, 3D modelling and drafting of the precast concrete main cross-walls structure for two of  three blocks of apartments. Liffey Contracts was the main contractor.

The Windsor Hotel is a new REZz micro sleeper hotel on MacCurtain Street, Cork and extends to 72 bedrooms in eight storeys over basement. Petruf Consulting provided structural engineering analysis of the precast concrete main cross-walls structure for the whole building. Townmore Construction was the main contractor.

As the precast design contractor on The Windsor Hotel project, Frank was instrumental in resolving key structural challenges such as developing an innovative detail to support the floor slabs using the walls above, where shear loads were excessive.

Frank elaborated in his submission: “I had proposed a precast concrete transfer wall with slabs hanging from this wall as a structurally adequate solution for multi-storey and high-rise buildings with the main cross-walls structural system, where the wall is bearing on slabs with large spans and no support underneath the wall to transfer the loads down to submission.

“Usually, the transfer wall carries loads from a few storeys above as well. To minimise loads acting on the transfer wall, I designed all walls above as very stiff transfer walls with minimum vertical deflection. The benefit of this is that the transfer walls at each level contain sufficient reinforcement to transfer the loads rather than the bottom wall being excessively reinforced, which is more practical for production and site placement.

“For the connection detail to resolve the hanging slabs, I used L-shape starter bars placed at the bottom of the structural screed with vertical legs anchored into the bottom of the transfer wall. I checked the horizontal legs of the starter bars and structural screed locally at the starter bars for horizontal sheer stress and the vertical legs for pull-out force.

“Using this innovative detail, no heavy beam underneath the very bottom transfer wall is needed. All loads are carried by the transfer walls and the slabs carry UDL loads from one storey only. The 8m spanning slabs, designed as continuous slabs, usually require reinforcement of H12 at 150mm c/c to perform within deflection limit with the depth of 250mm for the slabs.”

Petruf Consulting takes a collaborative approach to every job to ensure a quick design approval process, hassle-free production and a smooth-running site. This is supported by the state-of-the-art Allplan Precast BIM software package it uses.

A native of Slovakia, Frank is an enthusiastic and highly-motivated chartered structural engineer with fresh, creative and ambitious ideas to manage and design projects in a better way. Over the past two decades, he has gained extensive management experience, strategic planning and design skills on a wide range of projects in Ireland and abroad. For the last 13 years, he has used BIM to approach the structural aspect of a project in an innovative way while maintaining the architectural design intent.

“Our goal is to provide 3D modelling that is easy to follow and save our clients’ money. There are huge savings to be made from our precast proposal compared to traditional block work,” he concludes.

Petruf Consulting Structural Engineers Ltd

51 Baroda Court,

Newbridge,

Co. Kildare,

W12 HR58.

Telephone: 045 8452991 / 085 1653897

Email: [email protected]

This article was published in Building Ireland Magazine, April 2022, Vol 8 No 4