The construction of bridges has been a key focus area in Southeast Asian countries. Various bridge construction projects have been completed or are upcoming, improving connectivity and reducing travel time for commuters. Advanced engineering and designs are being deployed to build and maintain the bridges. Increasingly, it is also observed that the aesthetics of bridges are being given a high priority for the beautification of the country. Southeast Asian Infrastructure takes a look at two major bridge construction projects in the Philippines discussed at a recent conference organised by India Infrastructure…
Cebu-Cordova Link Expressway
The construction of the Cebu-Cordova Link Expressway (CCLEX) was started in July 2018 and the expressway became operational in April 2022. The CCLEX was constructed under a public-private partnership. The length of the four-way expressway is approximately 8.9 km, including the main bridge, approach viaducts and causeways. The CCLEX crosses the Mactan Channel, connecting Cebu City via the Cebu South Coastal Road to Cordova via the Mactan circumferential road. It is approximately 7.5 km away from the MandaueMactan Bridge and about 8.9 km away from the Marcelo Fernan Bridge, making the CCLEX the third link from Mainland Cebu to Mactan Island. The main iconic feature of the CCLEX is the lighted crosses on top of the towers. Each tower has four crosses that are lighted with bright white LEDs.
The main bridge is more than 600 metres long and connects to the 917 metre long Cordova viaduct. This bridge is made mostly with single-column box girders and the embankment field in the causeways is contained by gabions for slope protection. The equipment used to monitor the main bridge includes stay cable accelerometers, GPS geometric controls for the two towers, expansion joint movement sensors and a road weather information system. The bridge has emergency parking areas at every km on the causeway. Weigh-in-motion sensors and weigh bridge stations are also installed at both ends of the expressway to apprehend overloaded vehicles. IP-based speed cameras and high definition security cameras have also been added for greater security.
This bridge is the first project in the country to use NU-girders, the preferred shape for medium- and long-span, precast concrete girder bridges. These girders were designed by the University of Nebraska, USA. The main bridge towers and other piers were constructed using climbing formworks, and form travellers were used to build the main bridge deck. A girder launching gantry, which was specifically designed for this project, was used to lift and install NU-girders high above the deck of the approach viaducts. Further, a seismic hazard assessment was conducted to develop a site-specific seismic design acceleration response spectrum and input seismic acceleration time histories, which were used for the three-dimensional, non-linear dynamic analysis of the bridge. The CCLEX can withstand earthquakes measuring 7.75 on the Richter scale with the earthquake epicentre located 118.75 km away from the bridge.
Bataan-Cavite Interlink Bridge
One of the major bridge constructions taking place in the Philippines includes the BataanCavite Interlink Bridge, which is being funded by the Asian Development Bank and implemented by the Department of Public Works and Highways, Philippines. The project is in the feasibility report preparation stage at present and is expected to take four-five years to be ready. The project’s objective is to provide a permanent road linkage between Bataan and Cavite, which will reduce the journey time from five hours to 30 minutes and ease traffic congestion through Metro Manila and the South and North Luzon gateways. The 32.15 km long bridge will be a four-lane drive (two for each direction).
The south channel is to be one of the longest cable stayed bridges in the world. The construction of the bridge is divided into seven phases or packages, with package 1 (P1) and package 2 (P2) as onshore approach packages where P1 is the Bataan land approach and P2 is the Cavite land approach. The connections to the road network of the cities will be made through elevated interchanges. Package 3 (P3) and package 4 are the north and south marine viaducts respectively that will cover the longest passages of the bridge. The major portion of the bridge will be constructed using single-cell box girders with single-column shafts, which will split into dual-cell box girders with dual shafts while approaching the cable-stayed bridges. Further, P3 will also have the Corregidor Island connection which will provide a turnaround facility.
Certain amenities will also be added to the island in the future for development and tourism purposes. Package 5 and package 6 involve the construction of the north and south cablestayed bridges with high-level viaducts to provide navigational channels. The architectural shape of the main bridge towers is inspired by the Philippines flag. The roadway lights for the full project will be long-lasting LEDs, powered by solar panels on top of the bridge. Additionally, computerised dynamic lighting will be installed on the bridge. The bridge will be constructed with wide shoulders and steel barriers that will enable commuters to get a clear view of the sea, enhancing their experience.
The project was started before the COVID-19 pandemic hit, which meant that DPWH faced lockdown and mobility restrictions, which were a big hindrance. However, technology helped bring everything together. Before starting the project, a combination of geophysical and geotechnical surveys were conducted for the site investigation. Some of the specialty studies conducted were marine hydrodynamics studies, durability studies, marine investigation and vessel collision hazard studies, wind engineering studies and environmental studies. Accident and terrorist vulnerability assessments were also done to make sure that the design of the cables and pillars is accident and terrorist protected.
In sum The Philippines is deploying advanced studies and technologies from the preplanning stage till the post-construction maintenance of the bridges and is undertaking challenging projects for the development of the country. Additionally, these projects are being undertaken not only keeping in mind connectivity improvements but also to promote tourism by beautification and addition of amenities and security. Newer designs like monopole pylons for cable-stayed bridges are being constructed instead of the traditional diamond-shaped pylons to ensure both cost optimisation and enhanced aesthetics. The agencies involved in the construction have made the best possible use of the pandemic and have been able to keep the work in progress. In-depth study and analysis of bridge designs have resulted in the successful construction of long and sturdy bridges with high-tech facilities