Desk Report,
The reason why the Chittagong bridge collapsed in two
The width and depth of the canal were increased for the waterlogging relief project. Retaining walls were also provided on both sides. But the width and renovation of the 50-year-old brick bridge on the road were not done. As a result, during heavy rainfall, the soil on both sides of the old bridge started to move due to hill erosion. At one stage, the brick walls of the bridge collapsed. As a result, a part of the bridge collapsed into two parts.
The reason why the Chittagong bridge collapsed in two
The investigation committee has submitted a report stating the reasons why a bridge on Bayezid Bostami Road in Chittagong City collapsed and split into two. The committee said that the bridge collapsed into two for a total of four reasons. The investigation committee formed by the City Corporation submitted a three-page report today, Wednesday.
City Corporation Secretary Mohammad Ashraful Amin confirmed the submission of the investigation report. He said that action will be taken as per the report’s recommendations. On August 7 at 5 am, one side of a bridge collapsed at the mouth of Starship Alley on Bayezid Bostami Road in the city during heavy rainfall. Traffic is currently moving on the other side of this bridge located on the Shital Jharna Canal. People travel from Gate No. 2 of the city to the Oxygen area through this bridge. The part of the bridge on the road from Gate No. 2 of the city to Oxygen collapsed. Currently, the part from Oxygen to Gate No. 2 is operational. The Chittagong Development Authority (CDA) demolished this part of the old bridge in 2010 and rebuilt it. 60 to 70 thousand vehicles ply this road every day.
The City Corporation formed a four-member committee to find out the cause of the accident and determine what to do to avoid it in the future. The committee was headed by the company’s chief engineer Anisur Rahman. The members were Commander Iftekhar Uddin Ahmed Chowdhury, Chief Cleaning Officer of the City Corporation, and Executive Engineer Mohammad Rifatul Karim Chowdhury, Executive Engineer of the Chittagong Development Authority, Md. Mahfuzur Rahman.
Four reasons for the collapse of the bridge
The investigation committee said that the main reason for the collapse of the bridge was its old structure. About 50 years ago, the bridge was built on a brick abutment wall, which holds back the soil and carries the load of the bridge. At that time, the distance between the two sides was six meters. Later, during the waterlogging relief project, the Sitala Jharna canal was widened to 13 meters and the depth was also increased. As a result, the length of the bridge did not match the width of the canal. During heavy rainfall, the soil started to move away from the bottom of the canal due to hill slopes. This weakened the foundation of the bridge and broke it.
The second reason is that a drain was made on the eastern side of the bridge to drain water. The water from this drain was drained directly next to the foundation of the bridge. This damaged the bridge.
In addition, the third reason is that when the bridge was built, there were very few vehicles on Bayezid Bostami Road. Now the number of vehicles has increased many times. Since it is an industrial area, various types of vehicles including heavy trucks, lorries, covered vans and other vehicles ply on the road and bridge. The bridge may be damaged due to the movement of heavy vehicles.
The fourth reason is believed to be that WASA has taken two large pipes along the bridge for water supply. The pipe connection has been established at this place. RCC boxes have been constructed to protect the pipeline. This is also why the very old bridge may be damaged.
Four recommendations to avoid accidents
The committee has made four recommendations to avoid such accidents on other bridges in the city. These are that the old bridges on those canals should be demolished and new ones should be built in line with the width of the canals that have been increased to reduce waterlogging.
Several organizations have built retaining walls along many canals in the Chittagong City Corporation area. Especially due to the digging of canals by CDA, the depth of the canals has increased. This is causing the previous retaining walls to give way. Therefore, it is necessary to demolish the old and risky retaining walls and build new ones. In addition, a list of bridges and culverts that are not capable of carrying very heavy vehicles should be prepared, safety signboards should be installed and, if necessary, heavy vehicles should be banned. The committee emphasized on ensuring that bridges and culverts are not damaged during the installation and transfer of pipelines of service organizations.
City Corporation sources said that a new bridge will be constructed over the Shital Jharna Canal under the ‘Chittagong City Corporation’ project for the development of various roads including the airport road and important infrastructure. The design of the bridge has already been finalized. The cost has also been fixed. The amount is 8 to 9 crore taka. The width of the new bridge will be 23 meters. Its length is 15 meters. Earlier, the length was six meters. The City Corporation has already issued a tender notice for the appointment of a contractor.
