https://www.thehindu.com/news/cities/chennai/velachery-rail-overbridge-work-resumes-to-be-ready-by-april/article30628763.ece 

A senior official of the Southern Railway said the Station Road ROB had remained incomplete because of the delay in execution of the mini ROB near the Velachery railway station. The construction of the mini bridge had stalled because of the poor condition of the soil. The clayey soil caused the concrete foundation to sink at a few places and so construction was stopped for several years. To overcome this problem, huge concrete slabs are being readied near the construction site and once the foundation work of the six spans is completed, the concrete slabs would be fixed above the arms and the road would be paved, he added.