OREANDA-NEWS. Repair of the tunnel collector using KANKOSEI method is going on at Tovarischesky prospect.

Vodokanal has started using new technology which allows repairing the existing sewage collectors without putting them out of operation and enforcing their structure. The KANKОSEI technology was originally developed in Japan, and further upgraded together with OOO “Transspetsstroi” to be applicable in the north-west of Russia. Its principle is as follows: plastic tape is spirally wound in an inner side of a collector. Then, a special mortar is fed into the area between the tape and collector wall.

This technology is suitable for renovation of St.Petersburg tunnel collectors for several reasons. Firstly, it allows to renovate collectors laid at the depth of 5-50 m and more without putting them out of operation, i.e. the working collectors. Secondly, it can be applied for tunnels with any diameter (1.2 - 4.7 m) and any cross-section (circular or horse-shaped), the interval between shafts reaching 550m. Collector sections with small turning radius (maximum 30m) are also not a problem.

Specialists of OOO “Transspetsstroi” together with St.Petersburg State Transport University contributed to the improvement of the technology: the techniques of controlled spiral winding, annular space grouting at big intervals between shafts and the annular filler itself were developed. The winding unit was also modernized and equipped to ensure uniform coating notwithstanding the changing cross-section of a collector.

The new technology ensures complex rehabilitation of tunnels and pipes including enforcement of structures in cases of increasing dynamic and static load and renovation of an old pipe surface. Such advantages allow to use this technology to protect a tunnel from additional loads and vibrations (for example, a tunnel collector can be enforced if the works on deep excavation or construction of a high building are planned in this area, or if the collector is under heavy traffic load).

This technology does not require any additional construction (excavation) works either on the surface or inside of the structure. The repair works can be performed within a short time with the minimum price as compared to the existing technologies.

Nowadays, in St.Petersburg, OOO “Transspetsstroi” has been implementing a pilot project on the renovation of the tunnel collector at Tovarischesky prospect using the new technology. The works are going on on the tunnel section of 850m in length, diameter of 1.8 m, at the depth of 9-10m above the ground, in restrained urban conditions and under the external influence (static and dynamic traffic load). All the works are conducted on the working collector. The renovation commenced three months ago; as of late July, 2014, 80% of works using the new technology has been completed.

Specialists point out that in the course of the successful project implementation the new technology proved its technological and economical efficiency and demonstrates a successful cooperation between Japanese and Russian experts.