Hongkong-Zhuhai-Macao Bridge – Die 180 m langen Tunnelelemente wurden in acht Einzelsegmenten von jeweils 22,50 m gegossen.

Formwork solutions for tunnel construction

Tunnels are complicated, let us help make their construction simpler

At PERI, we love tunnels. They are at the heart of a modern society, taking trains underground beneath our feet, allowing traffic to save emissions by making routes more direct, bringing water through mountains for green hydroelectric power, and hiding infrastructure to make life on the surface quieter and cleaner for those living nearby.

Their construction is taking place at a scale and number never seen before around the world, largely to cope with an increasing population and changing lifestyles and demographics. We understand the importance of these structures to society and how the safe and economical creation of these structures is vital to improving the living standards for millions of people. 

But we also understand the complexity for our customers when faced with such a project. Regardless of the construction method, there are always a high number of variables to control and account for. Solving complex engineering challenges whilst staying on time and budget is a challenge we love to face by applying our state-of-the-art tunnel formwork, shoring and scaffolding systems and years of engineering expertise.

PERI: the tunnel specialists

Despite tunneling taking place around the world at different scales for thousands of years, the complexity and size of these projects still requires the best in civil engineering innovation and design.   

The teams and specialities for tunnel construction usually consist of geologists, civil engineers, foundation engineers, tunnel specialists, road construction specialists, concrete technologists as well as planners for traffic and operational safety. This list alone provides a sense of the complexity of such construction projects.

In this network of specialists, we have made an international name for ourselves as a reliable partner of engineering, formwork, shoring and scaffolding systems for the most simple through to the most complex tunnel projects across all project phases from planning to completion.

Tunnel bypass Flüelen, Switzerland - The special support und moving construction comprised of elements from the PERI tunnel waler system which adapted exactly to each cross-section. The complete formwork unit could be moved on rails from section to section using pulling equipment supplied by the contractors. Due to economic reasons, setting and stripping were done mechanically.
KERN Tunnel system in use to create tunnels for rail, road, energy and other applications around the world. Specialist engineering and tunnel systems.

Tunnel construction methods and technology

The key role of concrete technology

The development of high performance concrete enabled a fundamental step forward in developing systematic construction methods in tunnel construction.  With these improvements to construction technology also came a more standardised set of methods to conceive, plan and implement tunnel construction in the most economically viable manner. 

Systemised formwork, shoring and scaffolding products to ensure the most cost-effective and efficient creation of tunnel structures have subsequently been developed. This allows standardisation of parts, integration and re-use of systems to reduce costs and improve construction speed, and a more reliable method of construction.

Crossrail Tunnelling Banner

Construction methods and structural forms 

The main criteria when selecting the construction method and structural shape are the tunnel cross-sections and their lengths. In addition, there are often curves and inclines in the course of the tunnel as well as varying geometries in the clear width and height. These changes to the standard cross-section can be required for many reasons, such as integration of parking and emergency stopping areas in transport tunnels, ventilation and service structures, train station boxes and plant and equipment integration to name a few.

In terms of construction, our tunnel construction methods include four types:

  • open design
  • mining construction method
  • lid construction
  • special or supplementary designs

Regardless of the construction method, and tunnel design, we can provide systemised tunnel forming products for square, rectangular, round, elliptical or special tunnel designs. With many variables to control such as groundwater and geological conditions, we understand that our customers need a dependable, high-quality and precisely engineered system to ensure the formwork operations are consistent and on programme. 

Structural forms in tunnel construction

Tunnel cross section types to consider during formwork design and construction method processes

See our engineering and tunnel technology in action

Our tunnel construction solutions are typically based on a single system - the VARIOKIT engineering construction kit — or bespoke steel formwork design and manufactured specifically for your project. Regardless of the level of automation required for the shuttering and stripping processes or the traversing movements, we can provide the right solution from our systemised or bespoke range.

The PERI system solutions cover all life-cycle phases of tunnel structures: from new construction to maintenance and repair. PERI UP system scaffolding is integrated in to the process for access on the construction site, such as for primary concrete works or secondary tunnel lining and services installation. 

 

PERI system technology in tunnel construction

From the very beginning, PERI has pursued a special modularity concept that sees two supposedly contradictory objectives as a unit and technically brings them together in product and component development. On the one hand, the PERI formwork and scaffolding systems are characterised by the greatest possible simplification in construction and handling. On the other hand, as highly standardised components, they allow a maximum of variability in their object-specific combination.

The functionally and logistically optimised concept ranges from a few core components with captive, self-locking and adjusting fasteners to a self-explanatory construction logic of the formwork and scaffolding systems to digital planning and execution tools, who ensure the construction and logistical project progress.

One system with ultimate flexibility - VARIOKIT engineering construction kit

The VARIOKIT engineering construction kit is the proverbial all-rounder. It is one of the few systems in the world that can be used without restrictions in tunnel, bridge and civil engineering construction. This essential customer advantage is the result of a high level of standardization and combinability of the system components, which are consistently based on just three core elements:

  • the steel bar Universal SRU
  • the climbing rail RCS
  • and the heavy-duty spindle SLS.

The VARIOKIT engineering construction kit consists of around 80% standard components; the remaining 20% ​​are special components adapted to the property. In addition, the ability to rent PERI standard components reduces the amount of tied-up investment capital. At the same time, the PERI customer has reliable access worldwide to the pool of technically and functionally tested and maintained system and product components. Another significant economic advantage of the VARIOKIT engineering construction kit is its ability to be expanded into an independently driving, hydraulically supported "tunnel formwork machine" that carries out many interlocking work steps precisely and automatically.