The 23-km-long coastal road between Visakhapatnam and Bhimunipatnam is vulnerable to landslides and road accidents.
Two major rock headlands protruding into the sea that had been cut to lay the road at Tenneti Park and Visalakhshinagar are major potential zones for landslides, according to a study made by Andhra University Department of Geo-Engineering based on satellite imagery pictures.
At Tenneti Park the road was laid without making efforts to bind the loose rocks. The fractured rock boulders without lateral support are liable to collapse and excess rainfall is likely to cause landslide posing a threat to the passersby.
Similarly, the hillocks at Visalakshinagar are highly weathered pockets. Heavy rains erode the surface and it is likely to result in making the roads slippery.
A number of foothill areas have also been severely altered leading to rock and soil creep on to the road. Huge rock blocks are often rolling down on to the road. Owing to compositional variations, soil creep is also become active at places.
Erosion
The road is also passing through the intensely gullied quaternary red sand deposits near INS Kalyani which are known for geological and archaeological importance.
Some nine soil samples were collected along the road alignment to assess California Bearing Ratio to study erosion and strength characteristics revealing high erosion characteristics and low strength.
At places, migration of coastal sands on to the road is causing road accidents. Motorcycles are skidding due to the slippery nature of migrating beach sands. The existing road has two potential threats. On the seaward side there may be a chance of road breaching by the wave attack and on the landward side, man-made landslides and soil creep may take place.
Andhra University Geo-Engineering department head P.Jagadeeswara Rao told The Hindu that a joint study by him and P.V.V. Satyanarayana recommended building of retaining walls, grouting, rock bolting and riveting, geo-netting and iron-netting and turf as remedial measures to overcome the problems.
The study area consists of Peddagedda river, Maddigedda rivulet and a number of non-perennial streams terminating in the Bay of Bengal. These rivulets have significant influence on landmass denudation leading to sand deposition on road and breaching. Rushikonda, Bojjannakonda, and Erramattidibbalu, are the major tourist attractions besides resorts, IT parks, Cinema Studios, INS Kalinga and educational institutions developed adjacent to road, thus causing huge traffic load.
Unscientific construction of road coupled with topographical alterations at Tenneti Park and at Yerramattidibbalu is leading to accidents.
