THE Cebu-Cordova Link Expressway (CCLEx) is a combined toll bridge and causeway stretching 8.9 kilometers across the Mactan Channel, making it the longest and tallest bridge structure in the Philippines.
Connecting the city of Cebu to Cordova on the island of Mactan, CCLEx has reduced travel time between Mactan and Cebu International Airport by 40 minutes. Prior to implementing this project, Cebu was only connected to Mactan through two bridges in the northern area. This third inter-island connection in the south is relieving traffic congestion on the two original bridges and improving regional tourism and the economy.
As part of a temporary design joint venture, Sener was retained as the lead engineering firm to provide detailed engineering design, manage the multi-organizational design teams and offer technical assistance during construction.
“Along with designing the main assets associated with the project, Sener carried out the management and coordination of the inter-company design teams,” said Jordi Revoltós, bridges and viaducts discipline head at Sener.
The project includes designing a four-lane superhighway, featuring several bridges and access viaducts connecting to the main cable-stayed bridge, making it a spectacular sight and facilitating commerce throughout the region.
Complex site conditions, integration
Heralded as one of the most ambitious infrastructure projects in the Philippines, CCLEx presented site challenges, including extreme seismic conditions and a unique marine environment. The area is prone to typhoons with winds as strong as 250 kilometers per hour, requiring a structural design that could withstand the high seismic activity.
However, with design teams across multiple organizations working on the project, Sener faced design compatibility issues when connecting the viaducts to the main bridge structure.
“Since the approach viaducts connect with support at the mid-span of the bridge, special coordination [needed to be] developed to ensure a joint and compatible design,” said Revoltós. Therefore, effective interaction was a key factor in obtaining a balanced design.
Another challenge was that the project needed to be constructed entirely over water on a tight timeline. This complex construction sequence required software that could integrate with all design parameters to develop models that incorporated modifications from the construction site. Sener realized that they needed flexible, interoperable bridge modeling software.
“An [unsuitable] choice of calculation software [would lead to] increased time and costs during the design phase, while jeopardizing final approvals needed before construction,” said Revoltós.
OpenBridge provides digital solution
Sener selected OpenBridge based on its flexibility, collaborative design capabilities, and automated calculation features.
“The high flexibility of OpenBridge to develop models with modifications requested from the construction site, together with the short time required to adapt previous bridge models to new structures, led us to choose this software to design all bridges and viaducts by Sener,” said Revoltós.
Using Bentley’s application, they performed coordinated multi-discipline modeling and analysis, enabling them to make the geometry adjustments that would ensure design compatibility between the structures. Working in an open digital environment allowed the geotechnical and bridge design and construction teams to share information and determine the optimal bored pile diameters for the main bridge and viaducts. They also ensured that the structural solutions could withstand the seismic conditions and 250-kilometer-per-hour winds.
Sener also used OpenBridge to conduct detailed structural checks, which ensured that each structural element was correctly developed and verified. Meanwhile, automating post-processes allowed the team to have complete control of the design schedule, adjusting resources and tasks as necessary. The software’s versatility, interoperability and intelligent modeling and analysis facilitated a fast-track design process and model-based construction workflows to address the complex construction sequence and constrained project schedule.
Digitization reduces time, costs, environmental impact
Implementing collaborative digital modeling and analysis processes using OpenBridge streamlined workflows, enabling Sener to timely develop the models and meet the project schedule. OpenBridge’s flexibility to update models simplified the geometry adjustments required for design compatibility.
This capability reduced coordination time between design teams and allowed them to achieve high-quality digital designs. Based on the detailed calculations, the design teams reduced the dimensions of the foundations and minimized the impact on the coral seabed. Having highly accurate models in an open digital platform facilitated collaboration with the construction team, optimizing time on site.
Furthermore, Bentley’s application automated post-processes, enabling Sener to generate calculation reports flexibly and efficiently, saving additional time and costs.
“The use of OpenBridge software enabled the bridge team to reduce the time and costs associated with post-processing by almost 30 percent,” said Revoltós.
Working in Bentley’s connected digital environment also improved review and approval efficiencies, accelerating approvals of different parts of the project, enabling construction to begin in the shortest possible time. The intermediate control steps enabled by the software, together with the quality control sheets, made internal verification efficient and traceable.
“The use of OpenBridge, in conjunction with internal quality control processes, minimized potential errors in the final product,” said Revoltós. The successful delivery of CCLEx is an example of Sener’s technical expertise on the most technically complex projects.
Amy Heffner is the director of product marketing at Bentley Systems, an innovative infrastructure engineering software and cloud services company.