DAVAO CITY (July 23) – The Department of Public Works and Highways has commissioned a private geotechnical firm to conduct a subsurface investigation along the collapsed section of the Davao-Bukidnon Highway in Marilog District to determine the extent of ground instability and identify appropriate engineering interventions.
The study is being conducted by a team led by geotechnical engineer Dr. Applegen Joyo, who said the survey has been underway for the past three days.
The team is using Multichannel Analysis of Surface Waves (MASW) and other geotechnical methods to determine the properties and condition of the soil beneath the highway. The results will help engineers assess the stability of the affected area and recommend measures for the road’s permanent rehabilitation.
The investigation follows the collapse of a portion of the highway in Lower West, Marilog Proper, on the night of July 17 after days of heavy rainfall saturated the ground and triggered a landslide.
The incident also forced the evacuation of 11 families whose houses stood near the collapsed section.
The displaced families have been transferred to a one-hectare relocation site donated by an Indigenous community after authorities declared the area unsafe because of the continuing threat of landslides.
Among those displaced is Vivien Mae Canongas, whose family had lived in the area for 12 years.
“When the ground started moving, we panicked. We watched the soil beneath our kitchen slowly erode, and we feared we would be trapped,” Canongas said.
Barangay Captain Jeanette Suan said local officials had repeatedly warned residents about the danger of settling along the unstable slope.
“We have been reminding them to leave because the area has long been identified as landslide-prone, but only a few heeded our warnings,” Suan told Newsline Philippines.
The barangay is currently focused on providing temporary shelter and assistance to the affected families while awaiting a permanent relocation site.
On Thursday, Transportation Secretary Vince Dizon inspected the damaged highway and assured residents of government assistance.
“They can no longer return to their previous homes because the area is extremely dangerous and is also within the road easement,” Dizon said.
He said emergency repairs on the highway are expected to begin next week to restore traffic flow. However, he emphasized that the repairs would only be temporary while engineers complete the geotechnical assessment and prepare a long-term rehabilitation plan.
The Davao-Bukidnon Highway is one of Mindanao’s major transport corridors, linking Davao City with Bukidnon, Cagayan de Oro, Misamis Oriental and other northern Mindanao provinces. Thousands of passenger vehicles and cargo trucks transporting agricultural produce, manufactured goods, and other commodities pass through the route daily.
Marilog District has long been identified as a landslide-prone area because of its steep terrain, prolonged exposure to heavy rainfall, and highly weathered soil. During heavy or sustained rains, water infiltrates the ground, reducing the soil’s strength and increasing the likelihood of slope failure.
The ongoing geotechnical investigation is expected to provide critical data for designing a more resilient highway and reducing the risk of future landslides along one of Mindanao’s busiest road networks.
For the displaced families, however, the priority remains finding a permanent home where they can rebuild their lives without living under the constant threat of another landslide.-Eugene Hinutan
