Submerged applications

Service Specifications for Submerged Applications

Submerged applications using trenchless technologies allow for the installation of intake structures, outfalls, return lines, and pipelines under the sea or in waterways with precision, safety, and minimal environmental impact. This service is defined by the following technical parameters:

• Main applications: Submerged tunnels, microtunnels for outfalls and intakes, pipelines beneath the waterline, underwater crossings, deep intakes for desalination, return pipelines, and connections to existing marine structures.

• Construction methods used: Ground-controlled microtunneling, pipe jacking, Direct Pipe® for steel pipelines, and directional drilling in specific sections. In the marine zone, operations are coordinated with professional divers or ROVs.

• Ground conditions beneath the water surface: Alluvial soils, saturated sands, silts, or mixtures typical of coastal platforms. Water pressure, permeability, front stability, and soil behavior during pressurized excavation are taken into account.

• Depth and distance from the coast: These are determined by the intake or discharge location, the required water quality, protection against sediment, and the need to ensure long-term stability and operation.

• Pipe diameters and types: From non-accessible pipes (concrete, steel, HDPE) to accessible tunnels for high flow rates. The choice depends on the project (intake, outfall, return, marine bypass) and the operator.

• Civil engineering requirements on land: Pitheads and receiving pits, platforms near the coastline, access points for heavy machinery, a sludge treatment plant, pumping equipment, a welding area, and facilities for handling long or large-diameter pipes.

• Integration with marine structures: Connection of the tunnel or pipeline to underwater structures, anchoring, ballasting, final driving, and verification through underwater inspection. Work windows are scheduled for periods of favorable sea conditions.

• Pressure Control and Stability: Pressurized methods (EPB or slurry) ensure the stability of the cutting face in saturated soils. With Direct Pipe®, continuous thrust and the integrity of the steel are monitored under marine conditions.

• Quality Control and Final Inspection: Monitoring of excavation parameters, alignment, excavated volume, chamber pressure, thrusts, and stresses. Leak testing, CCTV inspection, and verification via diving or ROV at the marine connection.