What type of tunnels are most suitable for storm drainage works?

Key factors in the choice of storm drainage tunnels

Before determining the most appropriate type of tunnel, it is essential to analyze certain factors:

• Soil conditionsThe stability and permeability of the ground influence the choice of excavation method.

• Volume of water to be handledDepending on the design flow rate, the diameter and type of tunnel will be determined.

• Location and urban environmentIn densely populated areas, solutions that minimize the impact on existing infrastructure are preferred.

• Environmental impactThe protection of aquifers and integration with water ecosystems should be considered.

• Maintenance and accessibilityDrainage tunnels should be designed with adequate access for inspection and periodic cleaning, avoiding blockages that could compromise their operation.

Tunnels with balanced pressure tunnel boring machines (EPBs)

The earth pressure balance tunnel boring machines (EPB) are an excellent choice when working in granular soils or with a high water table. They are used for excavations in unstable ground where it is necessary to maintain the stability of the working face.

Benefits of EPB tunnels in storm drainage:

• They allow digging in sandy or soft clay soils.

• They control water pressure in saturated soils.

• They are ideal for projects in cities with high building density.

• They reduce the risk of collapse and seepage in areas with poorly cohesive soils.

Large diameter tunnels for storm sewers

Large-scale storm drainage systems require high-capacity infrastructure, such as tunnels dug by pipe ramming. These tunnels are designed to channel large volumes of rainwater and prevent overflows in urban areas.

Advantages of large diameter collectors in storm drainage:

• They can handle high rainwater flow rates.

• They are an efficient solution to mitigate flooding in cities.

• Reduce overloading of existing sewage networks.

• Its design facilitates the incorporation of retention systems to avoid sudden discharges in risk areas.

Submarine outfalls for rainwater evacuation

In certain coastal locations, the submarine emissaries are key to the evacuation of excess rainwater to the sea. These tunnels allow a controlled discharge, minimizing the impact on the marine ecosystem.

Main advantages of submarine outfalls in storm drainage:

• They convey stormwater to the sea in an efficient and safe manner.

• They prevent flooding in urban coastal areas.

• They reduce the risk of water accumulation on low ground.

• They are integrated with water quality control systems to avoid negative impacts on marine life.

Innovative applications for storm drainage tunnel design

Advances in trenchless construction technologies have enabled the development of more efficient and safer solutions for storm drainage. Some innovative applications include:

• Use of advanced materials in pipelinesImplementation of corrosion and abrasion resistant coatings to increase the service life of the tunnels.

• Incorporation of sensors in drainage infrastructuresReal-time monitoring of water flow and quality, facilitating management and maintenance.

• Temporary storage systemsIntegration of retention chambers inside the tunnels to regulate water flow during heavy rainfall events.

The selection of the type of storm drainage tunnel will depend on the geotechnical conditions, the flow to be evacuated and the location of the project.

• At urban environmentsthe technique of directional drilling is an efficient alternative for the installation of drainage pipes without altering the existing infrastructure.

• In unstable soils or soils with a high water table, it is recommended to use EPB tunnel boring machines.

• For coastal evacuations, the submarine emissaries represent the best option.

At EurohincaWe have the technology and experience necessary to design and implement tunnels adapted to every need.