Lee Tunnel, London

The Lee Tunnel is one of the two pipelines that convey an average of 39 million tons per year of wastewater, coming from 35 sewer pipes, built in the Victorian era as part of the network that still serves London, after 150 years.

The works began in September 2010 at the Beckton treatment plant, with the construction of the first of the four 80-meter wells, waterproofed by laying DRYset channels in the joints, then sealed with DRYflex resin injections.

The sections of the 120-meter-long milling machine were then lowered through the shaft, which in 2012 began excavating the connection tunnels, with a diameter of 7 meters.

The infrastructure is part of the strategic plan to improve and ensure the health of the Thames waters. The system routes discharges from London’s largest surplus sewer to Mills Abbey Pumping Station in Stratford, which handles 40 per cent of the total waste.

The four miles of tunnel were built beneath the Borough of Newham, from Abbey Mills to Beckton. The new tunnel helps prevent more than 16 million tonnes of sewage mixed with rainwater from overflowing into the River Lee each year, capturing and transferring it to Beckton’s sewage treatment facilities, which are in turn being expanded by 60 per year. one hundred to cope with the increase in volumes handled.

This is the deepest tunnel ever built in London. This involved excavating in conditions of high groundwater pressures, along four miles of extraordinarily abrasive soil and without lateral vent pipes.

Owner: Thames Water Utilities

Structure: Engineer Emmanuel Costes, London

Construction: Morgan Vinci Bachy JV, London

Waterproofing: Drytech UK, London

Double waterproof pump wells, Copenhagen

Drytech has designed a special waterproof pump shaft that allows companies to create pumping points inside the bed.

The wells are made in the Bedano workshop, in Switzerland, and shipped to the construction site, wherever it is in the world, where they are prepared by the Drytech technician.

This is the case of the construction site opened directly in the North Sea, where 36 pump wells were installed, subsequently sealed and incorporated into the bed.

Once its function is exhausted, the Drytech pump well is waterproofed both externally and internally.

Once the casting is complete, the joint between the well and the bed is injected with DRYflex expansive resin, which seals the element by pressure, wrapping around the entire thickness of the bed.

Any water flows inside the well are instead rendered harmless by the lid sealed with gaskets both on the circumference of the well and on each of the sealing bolts.

The use of the Drytech System resulted in a saving of several weeks on the time required for the construction of the waterproof basement.

Waterproofing: Drytech Italy

Milan subway restoration

Drytech has rehabilitated some sections of the Milan underground, during the night closure of the service, therefore without interfering with the normal circulation of trains.

The interventions were carried out with injections of DRYflex expanding resin in the joints between the slab and the inverted arch, for the entire thickness of the concrete structure of the tunnel.

The DRYflex resin is effective even in the presence of pressurized water. This made the intervention possible despite the enormous extent of the infiltrations.

Line 2 of the MM was built between the end of the 60s and the 70s without waterproofing, because the water table was much deeper. The closure of the Milanese manufacturing activities in the 1980s reduced water consumption and raised the level of the aquifer up to the tunnels of Line 2.

The infiltrations are controlled by pumping systems active 24/7, but in periods of heavy rainfall some sections were flooded. A series of waterproofing interventions for some tunnels was thus decided, carried out by Drytech between one and five in the morning.

Algiers subway restoration

Drytech has rehabilitated 5 tunnels and 5 stations of the Algiers metro, for a total of 4 km.

The proximity to the sea exposes the structure to a water table of 6-8 meters.

During the construction phase, various systems were used to waterproof tunnels and stations, but none of these managed to guarantee 100% waterproofness.

Hence the need for definitive reorganization. The Algerian Ministry of Transport has commissioned the Eurometro Society – London consultants specialized in the subway sector – to identify a solution to the problem of infiltrations.

After a worldwide survey, Eurometro proposed the Drytech Restoration System, based on injections from the inside of the DRYflex acrylic resin structure.

The Line 1 tunnel is made up of 10 meters long waterproof concrete segments, connected by 2 recovery joints interspersed with an anti-seismic movement joint.

Waterstop tapes were inserted into the joints, which only worked in 45% of the joints.

The joints of the adjacent structures, of the stations, of the ventilation ducts etc., were instead waterproofed with bentonite expansive profiles, the expansion of which however proved to be limited compared to the shrinkage of the concrete.

Even the jet shots at the air intakes showed infiltrations.

The thermal changes to which they are naturally exposed produce structural movements that split the polyurethane used to waterproof them.

Polyurethane, in fact, being semi-rigid and adhesive, undergoes the movements of the structure and, when they are particularly large, it cracks or loses adhesion.

Finally, shrinkage cracks were produced in the concrete which represented as many points of permeability of the structure.

The Drytech renovation was cataloged with the REAL system of Sir of Turin.
The application creates a virtual reconstruction of the structure, with all the information relating to the remediation intervention.

An X-ray that allows a quick and interactive consultation of images and data relating to the individual interventions performed.

Hanging swimming pool, Ascona

Overlooking Lake Maggiore, immersed in the woods above Ascona, the house with a hanging pool designed and designed by engineer Bonalumi for himself.

The pool occupies part of the top floor and, from the water, the view sweeps across the entire lake.

The bottom of the pool is the slab of the master bedroom.

The structure is a Drytech Tank in exposed waterproof concrete, with the edge of the pool completely covered with the Drycoat waterproof covering.

Project: Pianifica SA, Locarno

Pool and aquatic garden, Vernate

Infinity pool surrounded by an aquatic garden, also infinity.

With a breathtaking view of Lugano Lake, this suggestive swimming pool is a Drytech Tank with three walls against the ground and one – on the lake side – completely exposed.

Project: Franzi and Canetta Architects, Noranco

AlpTransit Control Center, Pollegio

The Polleggio Operation Center manages the railway traffic of the Gotthard and Monte Ceneri base tunnels.

Known as “The Periscope” for its futuristic architecture, the POC is one of the four SBB operating centers in Switzerland, together with the ultra-modern centers of Lausanne, Olten, Zurich.

Height and shape of the building are the architectural response to two functional constraints.

The POC marks and declares the entrance to the Gotthard base tunnel. It is a symbol.

To be perceived as such by the railway and the motorway it was developed in height.

The second constraint is the dimensional incompatibility between the control room and the type of an office building, which has led to accepting the contrast and expressing it in a radical way. Thus, the double-height slab of the control room is grafted onto a trunk of office space, arranged diagonally on the lot.

The POC therefore appears as a sculptural object animated by a twist between the two volumes.

Seen from a moving vehicle it transforms, changing its proportions and offering different states of balance.

Client: Canton Ticino logistics section

Project: Architect Bruno Fioretti Marquez, Berlin

Structure: Ingg. Borlini & Zanini, Pambio Noranco

Construction: CSC, Lugano

Waterproofing: Drytech Ticino, Bedano

Drytech Tank: 711 m²

Prefabricated underpass, Crema

The railway underpass of Indipendenza street in Crema allows the passage of a road and a cycle path under the railway path. The work was carried out without interrupting the overlying passage of the trains.

The Drytech Tank made it possible to prefabricate the monolith near the tracks and push it to its final location with an excavation that gradually replaced it for the ground supporting the railway line.

Once positioned in place, the monolith was waterproofed in its critical points (cracks and joints) with DRYflex expanding resin injections.

Made ex-post, the waterproofing did not risk being damaged during the launching operations.

The expansion joints were prepared with DRYset injectable waterstop tapes.


Structure: Ing. Terzini, Crema

Construction: De Fabiani Spa, Cavenago d’Adda

Waterproofing: Drytech Italia, Como

Drytech Tank: 3’600 m²

Renovation with Ex-Post Drytech Tank, Italy

Due to an underestimation of the water table, the waterproofing of the underground in this prestigious residential complex was not planned.

Unfortunately, after the construction was completed, a peak of the seasonal water table flooded the -2 level, making the garages unusable.

At this point Drytech was involved to restore the underground.

The analysis of the structural and environmental situation by the Engineering has identified the best solution in the construction of an ex-post Drytech Tank.

The industrial floor built above the gravel filling was therefore demolished. The water table was brought under control with a well-point system.

We then proceeded to lay the cracking elements in the stalls and prepare the stalls / walls and stalls / columns joints with the DRYset Channel.

The numerous crossings produced by the well-points have also been suitably prepared for the waterproofing injection, once the concrete has matured.

The new waterproof concrete slab based on the Drytech recipe was then cast.

To ensure the height of the extrados, it was necessary to create the sealed platform and the industrial floor in a single fresh-on-fresh helicopter jet.

When the concrete has matured, Drytech has perfected the injection of programmed cracks, joints and crossings with DRYflex expansive resin.

Due to its elastic quality, the resin is re-injectable, so it guarantees the possibility of maintaining the system over the years.

The construction of the ex-post Drytech platform made it possible to waterproof the basements and to deliver the properties with the usable garages.


Restoration Project: Engineering Drytech

Waterproofing: Drytech Italy

Trenord railway underpass, Saronno

Then the excavation and casting of the Drytech waterproof concrete slab was carried out, resting on the bulkheads and prepared with the DRYset crack control elements. The whole operation took place in just three days, at the end of which the track was restored.

The procedure was therefore repeated on the other track. After another three days the line returned to full capacity, with both tracks open.

The excavation was then carried out under the slab, the casting of the platform floor of the underpass and finally the lining casting, directly against the micropiles.

When the concrete matured, joints, holes and programmed cracks were injected with DRYflex resin which, expanding, sealed them by pressure.

Drytech Engineering provided advice on aspects relating to waterproofing, collaborating with the structural engineer already in the design phase of the underpass.

Ownership: Trenord Railways, Milan

Structure: Studio I.R. Joined Engineers – Ing. Giuseppe Barbagallo, Catania

Contractor: SALCEF Spa, Rome

Waterproofing: Drytech Italy

Drytech Tank: 1,800 m²