Tunnel lubrication plays a pivotal role in the success of all trenchless methods while improving the performance of tunneling, pipe jacking, microtunneling, guided boring, and horizontal directional drilling systems. The right lubrication system not only reduces frictional forces along the pipe string, but today’s advanced systems also incorporate variable flows, pressures, and additional pumping strategies that enhance material flow and maximize the mechanical properties of the trenchless equipment design.
A common misconception in the trenchless industry is that the lubricant, often referred to as bentonite slurry, coats the jacking pipe and makes it slippery. While a well‐designed mixture will seem to have these results, lubrication mixtures are formulated based on the site’s geology, trenchless equipment design, and lubrication system capacity to maintain the open annulus created between the cutter head and the jacking pipe. In certain ground conditions, the use of an improper mixture or misapplication can lead to increased jacking loads or even failure.
High Pressure Lubrication Systems
Below is a general guideline, given as a starting point for your next project. We always recommend consulting with a mud engineer for an on‐site evaluation of your geology.
|Ground Type||Ground Conditions||Reactivity||Lubrication Mix|
|Coarse Soils||Sands, Gravel, Rock||Non-Reactive. Does not swell. Does not get sticky.||Water (pH-controlled), Bentonite. Addition of PAC or Xantham Gum may be required|
|Fine Soils||Clay & Shale||Reactive. Tendency to swell with water. Can get sticky.||Water (pH-controlled), Bentonite with clay inhibitor. Surfactant to reduce stickiness|
|Mixed Soils||Variable||Ground may react differently depending on the ratio of coarse/fine material||Mixture of Bentonite, Flocculant, or clay Inhibitor|
Akkerman produces a complete family of lubrication/mud pumps suited for the trenchless industry’s rigorous demands. High‐pressure lubrication pumps are the perfect complement to extend distances during pilot tube installations. These same systems are versatile and mobile for any trenchless project, like pipe jacking, microtunneling, auger boring, directional drilling, and vertical drilling applications, to name a few.
Super Excavators, Inc. has enjoyed a long partnership with Akkerman over the years. We originally bought a competitor’s microtunnel system and had nothing but problems with quality and service. Finally we called Akkerman and bought their SL36 microtunnel system. Since then we have never looked back. We have bought several other pieces of equipment from Akkerman. From GBM equipment to ABIS to several microtunnel cutting heads. They have been great working with our staff to customize the equipment for our specific needs. We have put their equipment to the test on several projects by pushing the envelope in long drive distances and very difficult ground conditions. The equipment has responded well and together we have made modifications to continue to improve on efficiency. In our business it is necessary to have people their when you need them. Akkerman has done a great job at supplying quality equipment and servicing our needs in a timely matter, helping keep our work on schedule.