WorldWide Drilling Resource®

To be noticed, give us a call: (850) 547-0102 or e-mail: 12 AUGUST 2020 WorldWide Drilling Resource ® Drilling Using a Twin Rotary System Adapted from Information by BAUER In France, construction of a 20-foot-deep and 72-foot-wide water retention reservoir in the city of Riedisheim, Alsace, the French construction company, DURMEYER SAS, decided to take advantage of some of the latest BAUER technology, the BAUER BG 36. With it, the company was able to deploy the twin rotary system with torque multiplier (DKS/BTM), a method developed by BAUER, in the country for the very first time. Vincent Keller, dirécteur général at DURMEYER explained some of the obstacles his crew worked through, “There were a lot of challenging aspects in this project in Département Haut-Rhin. The space was very confined and there were also train tracks located very close to the drilling operations. In addition to this, we also needed to make sure that the groundwater was sealed off during the entire operations. All these issues and also the fact that the construction soil contained stones over [9 inches in] diameter made us decide to use the twin rotary system method with a BG 36 from BAUER.” The unique thing about the twin rotary system is how it combines the CFA method (continuous flight auger) with provisional casing. This results in a cased borehole cre- ated with a CFA or hollow stem auger. “This method is particularly advantageous in areas with high groundwater and soil that are in danger of being lifted, and require drilling under water load during kelly drilling,” explained Tim Lämmle, managing di- rector of BAUER Machines SAS, the French sales subsidiary of BAUER Maschinen GmbH. In this project, the casing used in the twin rotary system means that erosion of soil underneath the train tracks could be avoided and perfect verticality of the piles could be guaranteed. Since this method can be used in many different soil conditions and due to its compact size, the rig is very efficient and ideal for drilling more complex installations. The safety aspects were also important to DURMEYER. Keller said, “In particular, the material ejection system, with chute and drilling bucket, offers our employees a high level of safety and comfort. It’s impressive how safe working on a construction site can be these days.” BAUER was also able to train DURMEYER operators. “Extensive operator train- ing and expert on-site support meant that we were able to operate successfully from the very first pile. We benefited a lot from the experience that BAUER has,” stated Keller. The BG 36 was used to create 96 piles for a water retention reservoir. C&G