Which parts of the project can Eurohinca take on (complete work, execution only, technical assistance, commissioning)?

Eurohinca can assume different scopes in a trenchless project depending on the contracting model and the maturity point of the design: (1) complete work: integral execution of the crossing, with planning and implementation and execution of the method; (2) specialized execution only: Eurohinca acts as a technical subcontractor for the trenchless package within a larger project; (3) technical assistance and engineering: support for constructability, methodology, planning, risks and support for bidding/construction; and (4) commissioning and monitoring: support for start-up and critical phases, procedures and follow-up to ensure production and quality. The choice depends on the criticality of the crossing, environmental constraints and distribution of contract responsibilities.

What criteria determine the spacing between intermediate wells in long pile driving?

The separation between intermediate wells (additional wells to divide a long drive into several drives) is defined, above all, by the balance between the thrust needed to move forward and the maximum allowable thrust of the system (piping + joints + equipment + attack well). In practice, the limiting criterion is usually the increase of pipe-ground friction with the length, and how it is managed with lubrication and geometric control. For the context of the method, see Pipe jacking y What is a pipe jacking?.

Main technical criteria (those that “command” the distance between wells):

Maximum allowable thrust and borehole reaction wall
The maximum length “without an intermediate shaft” is conditioned by the permissible thrust that the system can transmit without damaging piping/joints and without compromising the reaction wall of the well. This connects directly to the design of Attack and reception wells: pushing, hoisting and logistics.
Expected friction (geotechnical + diameter + length) and lubrication strategy
The greater the length, the greater the accumulated friction, especially in abrasive/heterogeneous terrain or with demanding geometry. The repeated lubrication capability and their operational continuity directly impact whether you need to intermediate wells or if you can solve with auxiliary solutions. For typical risks and mitigation (including lubrication and auxiliary stations) see Geotechnical risks in microtunnelling and their mitigation..
Water table, water pressure and front stability
If the section works with high water pressures or sensitive terrain, the requirement for face control, debris/sludge management and sometimes the complexity of the wells (pumps, treatment, HSE) increases. This can lead to reduce lengths per drive (Method/equipment criteria according to conditions in Choice of tunnel boring machine).
Geometric layout and control (line/curve), tolerances and sensitivity to the environment
Curves, variable coverage or urban environments (sensitive services) often penalize the practical length by increasing lateral stresses, corrections and risk of accumulated deviation; in these cases it is more common to segment with wells or to set up auxiliary systems and greater control.
Logistics and available space (implementation, permits, access, HSE)
Although the drive could technically be lengthened, it may not be feasible due to space for a well, crane access, stockpiles, sludge/debris management and safety. Key here are the requirements for Civil works and the service of Vertical wells, in addition to the specific requirements explained in Civil works and manholes requirements.

Important practical note: in long pits, before “putting in” intermediate wells, it is usually evaluated whether the layout can be resolved with auxiliary systems (e.g., planning of intermediate stations/push and go solutions) when justified by the project, as contemplated by Technical assistance and engineering and in Choice of tunnel boring machine.