Trenchless technologies are constantly gaining new application areas. Among the offers of machines for their implementation, we have equipment for horizontal jacking, all kinds of worm drills and microtunneling devices on the market. We have access to precise hydraulic jacking machines and for horizontal directional drilling (HDD) rigs. It can be assumed that the market of equipment for the implementation of underground installations using trenchless methods allows for the implementation of all underground installations, in particular in situations and places where traditional excavation technologies would cause difficulties for the environment or would be impossible due to the existing building conditions. There are, however, such projects, the execution of which with commonly known and used trenchless machines and technologies is difficult or even impossible to be fully trenchless. These include precise gravity installations, in which the main parameter is maintaining straightness along the entire length and a specific, very precise angle in relation to the level, called gravity slope. This decrease is precisely calculated by the sewer network designer. The lack of its implementation during construction prevents the proper functioning of the entire sewage network. Such installations include all sewer and retention connections and sewer interconnections. A particularly difficult case of such installations, where the disadvantages of typical trenchless machines and technologies are clearly visible, are installations connecting existing sewage manholes: typical DN 1000 or DN 1200 or other non-standard ones. Such installations can be described as the most difficult to implement and the most demanding. In such situations, there is no chance of a complete installation with trenchless technology, taking into account commonly available trenchless technologies. Typical machines, which can meet the given precision and allow for effective overcoming obstacles in the ground, require starting chambers larger than the cubature of a typical sewer well. Therefore, it becomes necessary to partially dismantle the existing infrastructure: usually a sewage well and a fragment of the adjacent area, which is usually the surface of a road or pavement.
Gravity Drilling Rig
To perform such installations 100% trenchless, the Gravity Drilling Rig has just been developed. This device and the technology of horizontal directional drilling, known as the technology of Gravity Drilling, was developed precisely in order to make all such installations fully trenchless, without the need for any interference with the existing infrastructure, in particular road infrastructure.