Consultant Says Age and Heavy Loads Affect Strength of NLEX Structure
WITH the ongoing major safety upgrade of the Candaba Viaduct, AMH Philippines, the engineering consultant for the North Luzon Expressway (NLEX) Corporation, further stresses the urgency of repairs and the need to limit the weight of vehicles using the southbound viaduct, citing aging and continued heavy loading among the factors affecting the current condition of the structure.
An engineering company from the University of the Philippines, AMH, said it has been helping NLEX since 2019 to monitor and assess the condition of the Candaba Viaduct and explained that aging, fatigue and continuous heavy loads are at the origin of the structural defects observed.
“The first factor is aging. Just like people, older structures lose strength over time. In addition, subjecting the bridge to heavy loads greater than those for which the bridge was designed causes continuous cyclic fatigue stress. Fatigue weakens the structure and if it continues, its health deteriorates. Here in the Philippines, the typical fatigue life of bridges is 50 to 60 years, and the viaduct is approaching that limit,” said Roy Luna, Director of AMH Philippines.
Luna said that during a reassessment in June 2022, using structural models, their team found that trucks using the southbound overpass should have a maximum of 10 wheels and not exceed a gross vehicle weight. of 33 tons. He also said repairs should be done immediately so the damage does not show up or spread to other areas of the bridge.
Taking into account the engineering studies and attaching great importance to safety, the NLEX Corporation has engaged its various stakeholders in the public and private sectors regarding the planned rerouting of trucks with 12 wheels or more.
“We routinely hold briefings and consultation meetings for our national and local government partners, clients in different industries and host communities whenever we implement major projects like this to that we can let them know what’s going on and address any concerns they may have,” said NLEX Corporation President and CEO J. Luigi L. Bautista.
Bautista said NLEX management recognizes and understands the concerns raised by truckers and local leaders that the rerouting will affect business operations and cause congestion on local roads.
“While our truckers, who serve as a lifeline to maintain supply chains, play a key role in the economy, the diversion plan seeks to balance the interests of the economy and public safety given the the urgency and need to repair the structure,” Bautista said, adding, “NLEX remains committed to addressing the plight of the various stakeholders and assures continued discussions with the relevant national government agencies.
Stakeholders who were informed included the Department of Public Works and Highways, the Regulatory Board of the Department of Transport and Tolls, the Chamber of Commerce and Industry of Pampanga, the Clark Development Corporation, the Metropolitan Authority of Subic Bay, the Philippine Builders Association, the Confederation of Truckers Associations of the Philippines, Inland Haulers and Truckers Association, Alliance of Concerned Truck Owners and Organizations, and Haulers and Truckers Association in the Watersouth.
Relevant local government units (LGUs) that were part of the roadshow included Apalit, San Simon, Mexico, Arayat, Sta. Ana, Magalang, Minalin, Mabalacat, San Fernando and Angeles in Pampanga; Calumpit, Balagtas, San Miguel, Pulilan and Guiguinto in Bulacan; Cabiao and Gapan in Nueva Ecija; and Concepcion in Tarlac. NLEX officials also met with the Governor of Pampanga and briefed Provincial Governors of Bulacan, Nueva Ecija and LGU leaders of Bamban, Tarlac; San Isidro, Nueva Ecija; and San Ildefonso and San Rafael, Bulacan.
In addition to explaining the current upgrade in meetings, management also mentioned to its stakeholders that it is accelerating the construction of a third overpass, which is expected to be completed by the fourth quarter of 2024.
To better preserve the overpass’s operational condition and ensure overall public safety, Bautista said NLEX will step up its fight against overloaded vehicles. The toll company strictly enforces Republic Act No. 8794, the law prescribing load limits.
The Anti-Overload Program aims to protect motorists by prohibiting overloaded trucks and trailers from entering freeways or directing them to the nearest exit as an additional load may affect vehicle control.
NLEX Corporation is a subsidiary of Metro Pacific Tollways Corporation (MPTC), the toll road arm of Metro Pacific Investments Corporation (MPIC).