A joint venture (JV) led by Shimizu Corporation has commenced the excavation of tunnels using the shield tunnelling method on the Philippines’ Metro Manila Subway Project (MMSP) CP101.

The tunnel boring machine (TBM) launching ceremony was held earlier this month, on 9 January, attended by Philippine President Ferdinand Marcos Jr and Jaime Bautista, Secretary of Department of Transportation. Shimizu’s JV partners include Fujita Corporation, Takenaka Civil Engineering & Construction Co Ltd, and EEI Corporation (a major local construction company).

The MMSP, dubbed the first subway system in the Philippines, aims to alleviate the traffic congestion in Metro Manila due to a rapid population growth in the area. A total of 17 stations and a depot will be constructed along the 33.1-km section connecting Mindanao Avenue in the northern part of Metro Manila to Western Bicutan in the southern part of Metro Manila, where the Ninoy Aquino International Airport is located.

In its press release, Shimizu said the JV will build the first 7.3-km section of the project – known as CP101 – from the depot to the north Metro Manila. This includes the depot, three stations and six shield tunnels that connect the stations (three northbound and three southbound). The CP101 project is scheduled to be completed in July 2027.

The design and construction works under the CP101 contract have been divided into three segments, Shimizu further explained. First, the construction of the depot, Tandang Sora station and cut-and-cover tunnel, which was carried out in November 2019. The purpose is to facilitate the surface to underground transition. Second, the structure work for the Quirino Highway station and North Avenue station, which was carried out in March 2020. Lastly, the tunnel construction and the architectural and MEP works for the Quirino Highway station and North Avenue station, which was carried out in December 2021.

The tunnelling work that has just begun involves the construction of six underground tunnels with a total length of 9.5 km and an inner diameter of 6.1 m, using up to six earth pressure balance (EPB) TBMs. The first two TBMs launched on 9 January were headed from the launching shaft at the depot to the Quirino Highway station. The northbound and southbound tunnels between North Avenue/Tandang Sora stations and Tandang Sora/Quirino Highway stations will be constructed in turn. Moreover, four TBMs will launch and arrive sequentially. 

Shimizu highlighted that, being the first subway construction project in the Philippines, the MMSP has gained much attention from the residents of Metro Manila and is highly anticipated to play a key role in relieving traffic congestion. The project has now reached a major milestone with the launching of the first boring machine, and is expected to reach its peak construction period in the coming years.

All images: Shimizu