An investigation is pending into cracks detected in more than 200 buildings in Chennai, India. While they are attributed to the construction of the first phase of the 90-kilometer-long, $3-billion Chennai Metro project, it is not clear whether the tunnel boring machines (TBMs) are the direct cause.
Administered by Chennai Metro Rail Ltd (CMRL), a joint venture between the Indian government and the southern state of Tamil Nadu, the project's first phase is to be completed by spring 2015. It will have two corridors with a combined length of 45 km. The underground section will be 24 km long with 19 stations. Delhi Metro Rail Corp. (DMRC), prime consultant for the first phase, will assist CMRL in an advisory role in the execution of the project.
The fact that 70% of the buildings that developed the cracks were very old could not be ruled out, a structural engineer close to the project told ENR. “The metro was built all over Delhi, including close to very old heritage buildings, and there were no incidents … however, it could have been a design failure. One cannot rule out negligence for not ensuring a minimum cone of influence,” he says.