
Avni is one of the four slurry TBMs provided by CRCHI to the Bangalore Metro. It was named Avni (which means “Earth Mother”) by the customer. The first excavation section of 1085 meter length was successfully completed on 6 January 2021. The second excavation section of 1131 meter length had some complex geological conditions. Plus it had to pass below several residential areas and temples that were more than 100 years old. So, the requirements for ground settlement and control were immense.
In view of the above constraints, the R&D team of CRCHI developed a TBM which could handle the hard rock and uneven stratum, and the large number of boulders. CRCHI equipped the TBM with a high-strength composite cutterhead and large size disc cutters, which optimized the disc cutter path, strengthened the cutterhead panel structure, added anti-loosening measures for the disc cutter, and realized efficient rock breaking.
The TBM was also equipped with advanced technologies such as air-liquid independent balance control, efficient slurry circulation system, and synchronous double liquid grouting system – all of which effectively solved the construction problems of the metro tunnel and enabled the TBM to cope easily with the complex geological environment.
Since its launch in 2020, the superior performance of the TBM has been fully proven and it has been well received by contractors and clients. With Avni, CRCHI has once again shown its TBM manufacturing and technological strength in the metro market of South Asia.