PWD starts structural audit for key South Delhi Outer Ring Road flyovers

A PWD official aware of the matter said that an analysis of these structures will be carried out over six months, followed by rehabilitation work.

The Public Works Department (PWD) has initiated the process for undertaking structural audit and consultancy for assessing key south Delhi flyovers on Outer Ring Road, including the Old RTR flyover, IIT-Africa Avenue junction flyover and Modi Mill flyover, officials said on Thursday.

PWD has initiated the tendering process for the audits and is likely to complete the bidding process by December 11. (HT archive)

The agency will undertake repair and rehabilitation work and also incorporate the culvert on the Barapullah drain on Lala Lajpat Rai Marg under the project.

A PWD official aware of the matter said that an analysis of these structures will be carried out over six months, followed by rehabilitation work. “Modi Mill flyover and Africa Avenue flyover were constructed in 2001, while the RTR flyover came later. All these flyovers are at least 15 years old and are showing signs of wear and tear,” official added.

The flyovers need repair of expansion joints or spalled concrete and in some cases the core structure or replacement of the elastomeric bearing connecting the slabs with the base, the official added.

An expansion joint is a small gap that provides space for the concrete to expand and contract. It is an iron joint placed between concrete slabs to prevent damage to concrete and absorb vibrations. The repair work focuses primarily on replacing expansion joints and elastomeric bearings — components that absorb stress, temperature-related expansion, and the constant weight of traffic.

Officials said that in many flyovers, spalled concrete and signs of honeycombing will also be addressed to prevent structural degradation. Concrete honeycombing is the formation of voids or air pockets in concrete, resembling a honeycomb like structure, due to poor filling of the formwork.

PWD has initiated the tendering process for the audits and is likely to complete the bidding process by December 11.

The official said the project will be divided into four stages. “The first stage will see inspections and tests, including rebound hammer test, Ultrasonic pulse velocity test, among ten types of evaluations to be completed by advance 3D reinforcement scanning which will take three months,” official said.

In the second stage, the agency will make a detailed report on specifications of works required for rehabilitation of the bridge and the third stage will focus on preparing a detailed project report and overseeing the rehabilitation work over the next year. The entire project will take 1.5 years, they added.

The project also includes design and execution planning for culverts and road widening near New Ashok Nagar. The consultant will be tasked with soil investigation, structural design, preparing good-for-construction drawings and ensuring coordination with multiple agencies, the official added.

The site, located between Holiday Inn Crossing and the Metro station, requires careful hydrological planning due to proximity to major stormwater drains and heavy footfall, officials added. The culverts will be designed to improve both vehicular and pedestrian movement and will include footpaths.