NH 66 damage sparks concerns ahead of monsoon; construction practices under fire

THIRUVANANTHAPURAM: National Highway 66 is approaching the final phase of its construction, yet several parts of the road have already been damaged, sparking concern. Recent heavy rains caused sections of the highway to collapse in Malappuram and Kasaragod. With the onset of the monsoon, worries are mounting. Experts point to unscientific construction techniques as the main cause of these failures.

The construction practices adopted did not align with Kerala's geographical features, climatic conditions, and soil composition. There are allegations that sufficient studies were not conducted beforehand. Due to continuous heavy rainfall, construction work in northern districts has been halted.

The highway passes through areas with loose soil, paddy fields, and regions with significant water flow. Some sections are elevated by up to 50 feet. In these areas, interlock bricks were placed on both sides, and soil was filled in between without proper compaction or reinforcement.

Public representatives had suggested building flyovers or elevated roads supported by pillars in such regions, but these suggestions were not considered due to cost concerns.

During the rains, the unstable soil has led to complete road collapses. The recent collapse in Kooriyad, Malappuram, is believed to have occurred under these circumstances. Even if a single interlock brick gets damaged, it can lead to the entire structure failing.

Recent incidents of collapse

Cracks and soil erosion were reported again yesterday in two more places — Thalappara in Malappuram and Kanhangad in Kasaragod. Near Mavungal in Kanhangad, a service road collapsed. Similar issues have occurred in various parts of Thiruvananthapuram, Kannur, Kozhikode, Malappuram, and Kasaragod, even while construction is ongoing. On Monday, road collapses occurred again in Vengara and Kooriyad in Malappuram. The preliminary assessment suggests that the displacement of paddy field soil was the cause.

Danger zones

• If the base of the road is not adequately reinforced, soil moisture can cause slipping and erosion.
• If the soil filled inside the interlock brick structures is not compacted, it can sink and collapse.
• If even one interlocking brick cracks, it can cause the entire structure to collapse.

Geological characteristics must be taken seriously
The road must be constructed after considering the geological characteristics of each location. Ignoring this can lead to dangerous outcomes.

The road must be constructed in a way that prevents soil erosion and landslides on either side. Strong retaining walls capable of bearing heavy loads are essential.

— G. Shankar, Architect

High Court seeks report

The Kerala High Court has sought a report from the National Highways Authority of India (NHAI) regarding the collapse of the highway under construction at Kooriyad in Malappuram. The court issued the directive while considering petitions related to the poor condition of roads. Justice Devan Ramachandran took the initiative, and NHAI has assured that immediate steps will be taken to restore the road. The case will be reviewed again on Friday.