Lets Talk Series - Tunnel Formwork - Asia Pacific APAC

Transyscon are proud to be representing within Asia Pacific region, one of the leading Tunnel Formwork design, manufactures and suppliers.

Some of the most commonly used Tunnel Formwork systems that Transyscon can facilitate are:

• Self Retracting;

• Classic/Conical Automatic Widening and Retracting;

• Double Length Feeding System;

• Full Round;

• External Formwork without Dywidag Bars;

• Bypass and Couplings Formwork; and

• Inverted.

Self Retracting

Self Retracting Formwork supports the thrust of concrete without the need for any anchorage to the formwork, slab or rock.

The Self Retracting system is significantly more efficient compared to traditional systems, whereby anchoring to rock or slab was required.

Transyscon can facilitate the design, manufacture, build and operation of bespoke Self Reacting hydraulic systems. To enable a much safer operation, arming and disarming of hydraulics and safety pins can be carried out automatically, minimising the need for mechanical tools, thus increasing safety compliance.

Classic/Conical Automatic Widening and Retracting

Automatic Widening and Retracting formworks are suitable for tunnels that have multiple sections of varying diameter, including tunnels that have conical geometry. In this scenario, it is necessary to have a formwork that can adapt to the various sections.

To optimise site safety, the Widening and Retracting is carried out hydraulically. Additionally, the formwork structure is equipped with a specialist lifting system that enables the adding and/or retracting of formwork panels.

The below figure is of conical formwork. Starting from 8.8 meters wide and after several steps of enlargement it reaches a width of 20 meters.

Double Length Feeding System

The Double Length Feeding System is an advanced hydraulic formwork. Suitable for tunnels whereby it is not possible to advance the formwork via wheels, or similar systems, since the reinforcement has already been positioned within the tunnel, thus creating no passage area.

Full Round

The Full Round formwork is predominantly used for underground tunnels, including water pipes both hydroelectric plants and underground sewer systems.

The advantage of using Full Round formworks in water systems is to make the casting in one step, mitigating the need of connection joints between the insole jet and the face jet.

Over the years, water can infiltrate joints, thus create cracks, ultimately leading to leakage and costly maintenance repairs.

Full Round formwork guarantees efficiencies in concrete casting oppose to the traditional methods, thus leading to project timeline efficiencies.

External Formwork without Dywidag Bars

External Formwork is suitable for artificial tunnels. The below figure shows a solution without Dywidag bars between the internal formwork and the external formwork.

This type of external formwork guarantees a high speed of armoring and stripping down of the formwork, since the construction team are not required to fix bars between the internal and external formwork.

Bypass and Couplings Formwork

Bypass and Coupling formwork is used in tunnels to make the jets connect the main pipes of the tunnel. Transyscon are able to offer a solution on self-propelled rubber wheels with steering wheels. This solution allows the construction site to cast concrete and then quickly move the formwork to the next bypass without the use of special construction machinery. The formwork independently manages to exit the bypass, make the necessary manoeuvres and enter into the next bypass.

Inverted

Inverted formwork is used in tunnels to make the jets of the lower arch. Transyscon are able to offer various bespoke formwork solutions for Invert's, to solve individual project problems. The bespoke solutions can include:

• Invert formworks on rubber wheels or classic steel wheels on rails;

• Inverted formwork advancing with the ” double length ” system; and

• Formwork easy to move with construction crane.