Mumbai bridge collapse turns lens on city's infrastructure: Spot warning signs early to prevent mishaps, say experts

The recent road overbridge collapse at Mumbai’s Andheri railway station during a spell of heavy rain has raised concerns over the robustness of the city’s infrastructure. Following the incident, various authorities have stepped up their efforts to assess the stability of bridges in the city. Western Railways public relations officer Ravindra Bhakar said that the Western Railway, Central Railway and BMC, along with IIT-Bombay are currently in the process of conducting a structural audit of all 445 bridges going over rail tracks in Mumbai. He said that the audit is expected to be completed in about three to four months. Prominent urban development experts say that the audit is likely to assess whether the construction of the structures are as per the design and whether they are strong enough to withstand the load of people, vehicles and utilities. The process is likely to consider whether the designs of the bridges were appropriate in the first place. Sudhir Badami, a transportation expert and an IIT-Bombay graduate in civil and structural engineering, says, “Any bridge is designed to take a certain amount of load. This includes the dead weight (that of the structure itself) and the live load (weight which is not permanent in nature.) Utilities like wires and cables — which are very heavy — can be said to be dead weight as they are normally permanently affixed to bridges. To an extent, bridges are resilient enough to handle overloading, provided the support system is in condition. If the bolts on the top holdings and bottom holdings have rusted, this needs to be identified in the audits.” Numerous reports point to the possibility of utility cables leading to pressure on the Gokhale Bridge which links Andheri West with Andheri East. According to a report in  Hindustan Times, at least 60 utility cables ran below the paver blocks of the bridge. [caption id=“attachment_4701041” align=“alignleft” width=“380”]  The bridge which collapsed in Andheri. PTI[/caption] Another urban development expert and civil engineer, Shirish Patel, says, “Any structure will always give plenty of warnings before it collapses — whether it is through cracks or corrosion. These need to be identified through regular inspections — all that needs to be done is to be on the lookout. Most importantly, an inspection of the base of the bridge needs to be conducted from a very close distance — of just a few inches.” Patel also said that painting of steel structures is an important aspect, as it prevents them from getting corroded. Both Badami and Patel have assisted the Brihanmumbai Municipal Corporation (BMC) in various capacities in the past. Badami was earlier part of a road monitoring committee set up by the Bombay High Court. Patel is best known for being a co-conceiver of the satellite city Navi Mumbai. Western Railway PRO Bhakar said that the bases of bridges running across railway tracks will be inspected, but said that it is not clear as of now as to how this inspection will take place. He further said, “The IIT-Bombay will supervise the audits and suggest any new technologies that can be used for this purpose. The extent of corrosion and the load-bearing capacity of the bridges will be tested.” On the issue of structures collapsing despite the conducting of audits and inspections, Badami observes, “Audits should give a clear indication on whether a particular structure should be closed to people and repaired or not. Then, the question is whether the engineer decides on whether to, let’s say, close a bridge for the public pending repairs — or whether politicians take this decision. Many a time, politicians do not want to temporarily stop people from using a particular structure because they fear that there may be a hue and cry.” He further recalled, “In 2008 or 2009, there was a report of the standing technical advisory committee submitted to the BMC. In this, the panel submitted 68 points which the civic body needed to attend to — one of which was conducting audits of bridges.” This committee consisted of engineers from the BMC, Maharashtra government, and other institutes like Central Road Research Institute, Delhi and IIT-Bombay. Infrastructure under lens The mishap at Andheri on 3 July, due to which one woman lost her life, brought the spotlight on the condition of bridges in the city. The incident had led to train services on the Western line being halted for several hours. Authorities have shut down at least two overbridges which go across railway tracks in Ghatkopar and Malad due to concerns over their safety during an inspection. Last week, after the Andheri bridge collapse, cracks were also noticed on a bridge at the Grant Road railway station in south Mumbai. The bridge was closed and traffic diverted to other routes for a day. However, the bridge was later opened again to traffic after authorities concluded that the crack was only on the surface and the structure was safe. In October last year, a portion of a skywalk, which was being repaired, caved in near the Charni Road railway station in south Mumbai. One person was injured in the incident. The accident had occurred only weeks after a stampede at Elphinstone Road station , in which 23 people died and many more were wounded.