The following article was recently published in the 2022 annual Texas & Oklahoma Trenchless Report.
The project involved the construction of a 36-inch diameter HDPE water line inside of a 48-inch diameter casing, that ran under highway I-20 and a Union Pacific Railroad near Stanton, TX.
While using their 48SCII TBM with standard carbide cutter head, J & J Boring, Inc. encountered rock conditions midway across the bore which were not stated in the pre-bid GDR. The unanticipated ground proved challenging to mine with the initial TBM cutter head setup. After a few worn tooling changes, the contractor decided to develop a better solution to mine the rock.
Key benefits of owning an Akkerman TBM is the interchangeable cutter heads feature and the ability to access the face for obstruction removal. J & J, Inc. contacted Akkerman for a Disc Cutter Head attachment for their 48SCII TBM to fracture the hard caliche and limestone rock into pieces while maintaining alignment despite geological variations.
The 48SCII TBM Cutter Head features:
The lead 48-inch casing was welded to the TBM to counteract the rotational torque necessary to mine the rock with the uni-directional cutter head. The operators monitored the thrust loads on the cutters to ensure they did not become overloaded.