JSC Stroytransgaz has completed laying process of the pipeline 1220 mm in diameter in the tunnel crossing 2082 meters long in the Kobyla ridge in the Caucasus Mountains at the construction of the main gas pipeline Russia-Turkey (“Blue Stream”).
Wednesday, August 14, 2002
JSC Stroytransgaz has completed laying process of the pipeline 1220 mm in diameter in the tunnel crossing 2082 meters long in the Kobyla ridge in the Caucasus Mountains at the construction of the main gas pipeline Russia-Turkey (“Blue Stream”).
The last stage of works on pulling the pipeline through the tunnel in the Kobyla ridge coincided with natural disaster in Krasnodar area. At that time a waterspout passed close to the construction site and its destructive force did not touch the ridge. In the opinion of Mr. Alexander Vorobjiev Vice- President of JSC Stroytransgaz the natural disasters in Krasnodar area are the proof of the wisdom of using a tunnel method of laying pipelines in mountains. According to his words the pipeline protected by a tunnel crossing is safeguarded against landslides and unfavorable natural phenomenon and there is no potential danger of accident. Furthermore when using tunneling method of pipe installation the environmental impact is considerably reduced. The economic efficiency and operational reliability of the tunnel method of laying of the gas pipeline in mountains were highly appreciated by the Client – “Gazprom” and the state supervisory authority, Federal Mine and Technical Inspection of Russia – GOSGORTECHNADZOR. For laying of the pipeline in the tunnel in the Kobyla ridge the method of pulling of the gas pipeline on rollers was used. In the course of the work welding of the pipe string was performed at the assembly site just in front of the tunnel. Quality inspection of the weld joints was performed by an X-ray unit. Pulling of the welded section of the pipeline into the tunnel was carried out by a heavy-duty jack installation. As it was informed earlier the method of shield tunneling in mountains for laying of main gas pipelines was performed for the first time in Russia during crossing of the Kabyla ridge. The decision for constructing a tunnel in this ridge was made because of the complexity of its relief: there are 3 landslide areas with the total length of more than one and a half kilometer, there are 5 tectonic faults, numerous outcrops of rock and the slope of the ridge ranging up to 45 degrees. Participants of the works on designing of the tunnel were Scientific and Production Association ‘Mostovik” (Omsk) and JSC “Zakneftegazstroy-Prometey” (Erevan) which carried out technological operations with the pipeline. At present the specialists of the Stroytransgaz company and its subcontracting organizations will start hydrostatic strength and leak tests of the gas pipeline laid in the tunnel.
