AutoCAD Civil 3D bridges the downturn

Written by Martyn Day

Published Tue 2 Feb 2010

Founded 35 years ago by Dermot Roughan and Joe O'Donovan, Roughan & O'Donovan is one of Ireland's leading multi-discipline engineering firms, specialising in transport infrastructure and environmental engineering as well as its original core business activity of structural engineering. It has a particular reputation for innovative bridges, which include some of the most iconic in today's built environment such as the cable-stayed Boyne Bridge near Drogheda and Dargan LUAS (light rail) bridge in Dundrum. This award-winning practice currently has a staff of about 150 and is defying the current economic situation with a significant number of new projects both in Ireland and abroad.

For more than two decades the practice has had significant involvement in transport infrastructure planning, design and construction of road, rail and other associated public transport civil engineering projects. Roughan & O'Donovan is currently involved in several major bridge projects, including the Samuel Beckett Bridge over the Liffey in Dublin city, the proposed Narrow Waters Bridge across the Newry River at the head of Carlingford Lough and the iconic New Wear Bridge project in Sunderland. 

The Roads, Traffic and Transportation Group has designed a high proportion of the major motorway projects in Ireland in the last decade and has participated in all stages from route selection and constraints studies to final design and construction. Clients in this field have included the National Roads Authority (NRA), FCC, SIAC, Ferrovial, Roadbridge Sisk, BAM (formerly ASCON), Strabag AG, Dragados and Laing O'Rourke. The firm's expertise in design standards and contract procurement, including the original drafting and current update of the Design Manual for Roads and Bridges, has earned it a role as a key advisor to the Irish Government in these areas.

Using the most up to date and flexible software has been a key contributor to Roughan & O’Donovan’s reputation as a leading edge consulting firm. The firm has long used Autodesk products, principally AutoCAD. In recent years there has been an increased migration to AutoCAD Civil 3D, reflecting the augmented capabilities of the software to address the complexities of today's civil engineering projects.

“Civil engineering projects can be located in many different environments, but there is a particular set of challenges when it comes to designing infrastructure to fit into and complement existing constrained urban environments,” says Eoin Ó Catháin, chartered engineer and project manager with Roughan & O'Donovan. “We have been using AutoCAD Civil 3D for some years and find it particularly valuable in such situations because of the precision in detail that can be achieved in the designs.” 

He instances the two new signature bridges over the Liffey, which involve raising the quay levels for the approach roads while ensuring continued connections to the myriad of underground services such as drainage, water supply and other utilities. “We have used other civil engineering software but as Civil 3D has progressively added functionality up to the latest version we have increasingly migrated to it as our principal design tool for many of our urban design projects.” Roughan & O'Donovan has been using the latest editions of AutoCAD Civil 3D, including Civil 3D 2010 since late-2009, and has found the developing features of the software invaluable in the design of a number of recent schemes, notably the two new Liffey bridge projects at Macken Street (Samuel Beckett Bridge) and Marlborough Street, as well as in the development of specimen designs for Motorway Service Areas for the National Roads Authority. 

“The roads design for the Beckett Bridge was particularly challenging, as the new bridge was required to be set at a level significantly higher than the existing quays for operational reasons,” explains Mark Smillie, project engineer for the scheme within the Roads and Transportation group and a very experienced Civil 3D user. “The principal challenge for the design was to overcome the level differences between the bridge deck and the existing road network, while maintaining provision for access to existing buildings along the quays. A very detailed 3D road design was needed to model these interfaces accurately, as well as catering for the warren of underground services and utilities that had to be diverted for the works.”

Many aspects of the new Marlborough Street bridge project are similar in terms of road design, Mark Smillie says, but the interactions with underground services and utilities are even more complex. “The area is densely packed with existing services particularly drainage facilities. Significant complexity was added to our design because the principal foul sewer for north Dublin flows through a siphon under the Liffey in the location of the proposed structure.”

Civil 3D proved exceptionally useful in dealing with the underground utilities through modelling the pipe network in full 3D to map the underground environment accurately, Smillie says. “The dynamic nature of Civil 3D enabled the team to develop a design to separate the surface water runoff from the existing combined sewer network, a complex challenge, considering the labyrinth of other utilities.”

The extensive improvements to Ireland's motorway network in recent years prompted the National Roads Authority to provide high quality service areas for all road users. Roughan & O'Donovan was engaged to develop a conceptual design along with associated design standards for motorway service areas as part of a joint venture commission. These standards were then used in the design of the first three such service areas to be introduced into Ireland. In October, a Public Private Partnership contract was signed to design, build, finance, maintain and operate the first three motorway service areas with Pierse Contracting as the construction partner. 

Two of the service areas will be located on the M1 (Castlebellingham, Co. Louth and Lusk, Co. Dublin) and one on the M4 at Enfield, Co. Kildare. Each will provide facilities on either side of the motorway including a filling station, restaurant, convenience shop, toilet and shower facilities. A landmark building design will establish a recognisable identity for these new service areas. The sites are each of the order of 7.5 hectares and will be landscaped and include child play and picnic areas.

“This project involved a combination of site development design—including the internal infrastructure with services and utilities—and roads design, including connections with the already constructed motorways,” Mark Smillie explains. Civil 3D was the automatic choice of design software because of its proven flexibility in dealing with the many and various design elements. These included buildings, landscaped and parking areas, internal road network, motorway slip roads and roundabouts, underground storage tanks, sustainable drainage systems and other associated services and utilities.  

“With safety playing a primary role, the relationships between the various elements proved very problematic in the design process,” Smillie says. “Constraints involved the separation of heavy vehicles from passenger cars, fuel delivery facilities from the buildings, etc. Additional complexities arising included the need to control any surface water runoff or fuel spills within defined catchments so that suitable safety measures and appropriate treatment systems could be incorporated in the design, taking account of the constraints posed by existing environmental features such as watercourses.”

Developing a design solution with so many elements and constraints necessitates an iterative design process, Smillie points out: “This is where the flexibility of Civil 3D comes into its own, particularly in the three-dimensional environment. Utilising programme features such as grading objects and road design corridors, which dynamically update, enabled what could have been a very laborious process to be undertaken in a relatively efficient fashion. Essentially, we were able to push design objects around in the model to suit the various mandatory relationships and then get instantaneous visualisations of the resultant designs.”  

Roughan & O'Donovan usually assigns teams of designers to specific projects and the firm’s Civil 3D capability is expanding on an ongoing basis. Michael Blanch, Business Development Manager, points to the valuable build-up of a pool of experience and expertise in Civil 3D in the firm: “We have done post-project reviews of all of the commissions undertaken to date using AutoCAD Civil 3D which have indicated benefits over other software packages. The introduction of increased efficiencies to the design process positively impacts on our ability to be competitive in pursuing new work opportunities.” 

The firm considers that the Ire. “Our expertise in state of the art design technology allows Roughan & O’Donovan to maintain the firm's position as a market leading consultant,” Michael Blanch sums up. “This expertise has led to our involvement in many high profile and challenging projects, including, for example, the New Wear Bridge in the UK. We see our continued involvement in these high profile projects as essential to successfully navigating the current challenging market environment.”