BRIN Researcher Suspects Ineffective Drainage Triggered Landslides On The Bocimi Toll Road

Officers passed around the collapsed toll road on the Bocimi KM 64 toll road, Sukabumi, West Java, Thursday (4/4/2024).. BETWEEN PHOTOS/Henry Purba/agr/nym

JAKARTA - Head of the BRIN Geological Disaster Research Center, Adrin Tohari, suspects that the drainage system that is unable to accommodate rainfall runoff triggers landslides on the Bocimi KM 64-600 A toll road in Sukabumi Regency, West Java. "I suspect that the waterway on the left side of the road (outside side) is insufficient or unable to accommodate rainwater runoff from the road," he said when contacted in Jakarta, Antara, Thursday, April 4. Adrin explained that the runoff of rainwater overflowed into the slope and caused saturation on the road. If there is already saturation, this condition can cause the soil strength to decrease and cause landslides. He said the second factor was the formation of groundwater flow at the foot of the slope due to heavy rain. This factor often appears, especially on the slope of the peel or the slope of the pile. The flow of water that appears can cause disturbances on the legs of the slope, triggering landslides. "Those two factors need to be seen related to the drainage system in the road. Is the surface drainage system (surface drainage) or subsurface drainage (liversal pipes or culverts) effective designed or not?" said Adrin. Furthermore, he said that construction violence is very important, especially roads that are located in the location of piles of soil. The method of violence using geotextiles helps so that the slopes become strong. Adrin sees landslides on the Bocimi Toll Road as unlikely to happen suddenly, as every incident always has initial indications that arise before the event occurs. "I'm not sure it suddenly collapsed, there must be indications of cracks first, because the rain has been going on for a long time. Landslides don't happen suddenly, there must be symptoms first, both in violence or slopes," he said. On April 3, 2024, at around 20.00 WIB, a landslide occurred on the Bocimi Toll Road (Acronym Bogor, Cianjur, and Sukabumi) KM 64-600 to be precise on the Parungkuda Toll Road towards Sukabumi, Ciambar District, Sukabumi Regency, West Java. The paid road, which has not been inaugurated for a year, caused an MPV car containing two passengers to fall into an avalanche hole. The Sukabumi Police confirmed that there were no casualties in the incident. In addition, there was a truck and one MPV who had a single accident due to shock and tried to avoid going to the right and crashing into a median road.

Adrin appealed to toll road officials to carry out maintenance, observations, and monitoring at locations where it was suspected that landslides could occur. Moreover, it will soon enter the Lebaran homecoming season where vehicle volume tends to increase. "Officers in the field must observe whether there are symptoms of landslides in the construction of toll roads, either on slopes or piled up. Drainage channels are treated so that they are not clogged, if they are blocked, rainwater easily overflows and flows to slopes (of a stretch of landslides)," he concluded.