The road construction department on Thursday began the work of putting up a guard wall to support the base of an approach road to Harmu bridge in Ranchi, two days after it caved-in.

Around 1pm, an earthmover was seen cutting soil on the north side of the Harmu rivulet to make way for the construction of the guard wall.

"We would have started the work on Wednesday only. But due to Rath Yatra and bad weather, we could not start. If weather supports us now, we will be able to complete the work in 3-4 days," said one of the two contractors deputed by the department to supervise the work.

The guard wall will be constructed on both the north and south side of the bridge.

"Measurements will be done once the construction work begins but as of now, it is expected that the height of the guard wall will be about 7 feet, its width 1.5 feet and length 40 feet," the contractor said.

Executive engineer of the department Sanjay Kumar Sinha said that they had sent a junior engineer, Anil Prasad, on the spot to decide the designs and ensure that soil supporting the approach road did not get washed away at any cost.

Prasad, however, could not be contacted for comments.

On Tuesday, alleged faulty planning of the urban development department while executing the Harmu river rejuvenation last year led to two cave-ins on either end of the four-lane bridge on its approach road, better known as Harmu bypass, a 5km road that extends from Ratu Road Chowk to HEC checkpost.

The mess brought traffic on the busy bypass in the capital, which links VIP homes with Project Bhavan, the Assembly, state police headquarters and others, to a standstill for over four hours.