INNOVATIVE SOLUTIONS
Innovative technical solution for emergency repair of a pressure tunnel water supply pipeline during its air passage over a river bed
- 1 Institute of Mechanics Bulgarian Academy of Science, Sofia, Bulgaria
Abstract
The pressure water supply pipeline from the „Iskar Dam“, which has existed since 1981, is the main one for the water supply of the city of Sofia with drinking water. The water pipeline, for the most part executed as a concrete vault tunnel (mantel), passes through complex mountainous terrain with a large difference in elevation. During the long-term active operation, the steel part of the air passage of the water pipeline over the „Porkolitsa River” suffered a serious accident – internal pressure implosion of the steel pipe. The latter prevented the normal water supply to the city and an urgent repair was required by replacing the air-passing steel pipe of the water pipeline. The report discusses a proposed and successfully implemented innovative technical solution for monolithic installation of a steel pipeline in existing tunnel excavations with concrete lining by using self-compacting concrete with shrinkage compensated admixture and with the participation of special an internal crystallization chemical admixture, tailored to the specific requirements of the site. A prescribed composition of self-compacting concrete has been developed, the necessary control has been carried out during the batching plant production of the fresh concrete with monitoring of technical indicators. A technological regulation has been developed for the transport, laying and care of the concrete. During the site laying, standard sampling and testing have been carried out to prove the compressive strength at different ages of the concrete. Based on the above, in conclusion, the effectiveness of the developed and implemented innovative technical solution is certified.
Keywords
References
- V. Naidenov, Innovative self-compacting fiber-reinforced concrete with compensated shrinkage for machinery steel anchors grouting, VI International Scientific Conference “INDUSTRY 4.0”, Varna, June 2021, Year V, Volume 1/11, ISSN (PRINT) – 2535- 0153, ISSN (on line) -2535-0161, p. (12-15.)
- V. Naidenov, I. Rostovski, M. Mironova, Hybrid reinforced concrete with controlled volume deformations for hydrotechnical facilities, VII International Scientific Congress “INNOVATION 2022”, Varna, 20-23. June, 2022, p. (41-45) ISSN 2603-3771 (Online) ISSN 2603-3763 (Print)
- V. Naidenov, Extended research on the efficiency of internal crystallization chemical admixtures for cement concrete - mechanical and structural characteristics, Proc. of the IX International Scientific Congress “INNOVA’ 2023”, ISSN 2603- 3771 (on line), ISSBN 2603-3763 (print), p. (40-45).