Relining with HOBAS Protective Pipes for Gas Pipeline Gazela, CZ

The route of the new natural gas pipeline Gazela runs underneath a highway between the Czech cities Most and Chomutov and a railway track at a length of 165 m. A HOBAS GRP Protective Pipeline DN 1800 ensures that the gas is transported safely through this sensitive area. , At the beginning of 2013, roughly 3 years after its construction started in 2010, the new gas pipeline Gazela was officially put into operation. The 166 km long pipeline DN 1400 connects the Czech Republic via the OPAL pipeline to the Nord Stream pipeline. Through Nord Stream, which leads from Russia to Germany, Russian gas is transported to Europe at the bottom of the Baltic Sea. The new Gazela pipeline is connected to the Czech transmission system at four locations and plays an important role in ensuring interruption free gas supply. It will transport 30 billion cubic meters of gas per year. Most of the pipeline route could be laid in open trench, but there were some obstacles to overcome such as the highway from Most to Chomutov and a railway track. This called for a trenchless approach. The original plans involved two tunnels DN 1800, 38 and 88 meters in length. Since the highway and railroad line run parallel and quite close to each other, the original approach was eventually modified to build only one single 165 m long tunnel by means of shield tunneling. Inside of it, a protective pipe should serve as host pipe for the gas pipeline. , Due to their corrosion resistance and leak tightness, the designer and project manager decided to utilize HOBAS GRP Pipes DN 1800, SN 5000, PN 1 for protection. The 3-m-long HOBAS Pipes were transported into the tunnel, which has a diameter of 2560 mm, with a special pushcart. Each pipe was centered along the axis using spacers and a laser in order for the line to meet the exact project requirements. The annular space between the HOBAS Pipe and the tunneling shield was grouted with cement-concrete. Finally, the steel gas pipe DN 1400 was inserted into the prepared protective pipe and anchored with spacers. The client was very satisfied with the outcome of the project: “I would like to thank HOBAS for the good cooperation in this project and the consulting services on site. The installation of HOBAS GRP Pipes inside the tunnel ran smoothly.”