KEMROC Rotary Drum Cutter Tackles a Task Requiring Precision

Published: 4/3

To underpin an existing building in Germany, construction company Karl Immig used a 25t crawler excavator equipped with a KEMROC EKT 100 rotary drum cutter. to excavate rock with precision and with little vibration. Thanks to a 3D excavator grade control system, it was extremely fast and accurate.

With a new office building scheduled to be built next door, protecting the existing building from settlement would require excavating 5,900 yd3 (4,500 m3) of material. Ground conditions under the topsoil consisted of a hard, layered rock was difficult to loosen using the excavator bucket. Excavating the material from under the façade with a hydraulic hammer was not even considered because of the unavoidable, harmful vibrations to the building and the sensitive technical equipment inside.

The step-by-step method began with Immig’s operator placing the EKT 100 in front of the exposed façade to mill a recess approximately 1 ft (30cm) deep into the rock beneath the building. This was repeated at intervals of about 39 in (100cm) along the 49-ft (15m) long façade. Steel reinforcement was placed in the excavated recesses, which were then filled with concrete. After hardening, the strips between the reinforced sections were processed in the same way.

The KEMROC drum cutter attachment was used to excavate trenches for the new building’s utilities. The excavator used on this construction site was equipped with a 3D excavator grade control system that can be programmed with electronic planning data of the construction project, allowing the operator to create declines or embankments with the excavator bucket. This works just as well with a KEMROC drum cutter attachment as it does with a bucket. Once the system is calibrated, the drum cutter attachment can be guided with high precision.

This is exactly what the machine operator used when excavating the 262-ft (80m) long trenches for drainage pipes. The operator’s ability to quickly understand how the system worked became apparent towards the end of the project, as the package of replacement picks provided by KEMROC for the rental attachment was returned to the manufacturer unopened.