The fourth Novaliches-Balara Aqueduct (NBAQ4) serves around seven million customers in the Philippine capital. It is designed to last for the next five decades. NBAQ4 will allow three aging aqueducts to be replaced. The metropolis' water supply can be kept stable and geared for higher consumption in the future.
For the first time in the Philippines, a Herrenknecht tunnel boring machine with segmental lining was used for the construction, from January 2020 to August 2021. The use of an EPB Shield, with an outer diameter of 3.74 meters, was also a first for Manila.
NBAQ4 includes a new intake structure in the La Mesa reservoir, an outlet structure in the Balara treatment plants, the downstream network system and a 7.3-kilometer tunnel with an inside diameter of 3.1 meters. It is located under the busy Commonwealth Avenue in the center of the capital city.
Project-specific for the densely populated inner-city area, the TBM was equipped with a special sealing system, a combination of powerful main drive and jacking cylinders, adapted excavation tools for increased service life and a hydraulic wear detection system.
With less intervention on the cutting wheel to change cutting tools, time is gained while safety is increased. The EPB Shield is designed to drive up around multiple near-rectangular curves with exceptionally tight radii of only up to eighty meters.
The NBAQ4 water harvesting project is exemplary for many regions of the world that are looking for long-term safe solutions to provide their growing populations with the vital, yet increasingly scarce resource of water.
|Column 0||Column 1|
|Tunnelling length||7,300 m|
Rock: Tuff and volcanic rock
Novabala Joint Venture
1x EPB Shield:
Diameter: 3,740 mm
Lining method: Segmental lining
Cutterhead power: 480 kW
Nom. torque: 2,205 kNm
We are ready!