Codmah have the capability to bore steel sleeves in 3m, 6m or 12m lengths ranging from 300mm to 1500mm diameter. We have a large range of boring units with a selection of cutting heads capable of boring through soil, rock, and sandy conditions. With alignment and grade becoming ever more critical in today's services sector, we have introduced a laser guidance system capable of boring distances up 120m with a tolerance of +/- 25mm. This accuracy has proved beneficial on numerous occasions in both water and sewer markets from 100mm - 300mm and anything in between.
Our thrust boring units are designed to hydraulically thrust steel casing pipe into a simultaneously bored hole. The boring rig travels along a set of fixed rails embedded into a concrete slab, absorbing the thrust from the advancing boring unit. We use a variety of cutting heads that are carefully selected to suit the ground conditions. These vary from 'conical tungsten tipped bullets, clay picks to cutting discs' that are assembled in an angular or straight formation.
The bored earth (spoil) is extracted from the cutting face via a segmental auger system positioned within the steel pipe. The spoil is returned to the launch pit and recovered by an excavator where it will be stored or used elsewhere on the work site. This process is repeated until the cutting head reaches the retrieval pit. The cutting head and auger string are then removed leaving a fully supported steel casing providing support for the surrounding material and forms a conduit for the installation of the desired service. This environmentally friendly method reduces costs normally associated with open trenching.
Steel sleeved bores also provide good mechanical protection of the service that it houses. A low MPa flowable grouting mix can be installed to fill the annulus between the steel sleeve and service forming a truly maintenance free installation.