PSI - Issue 30

A.A. Antonov et al. / Procedia Structural Integrity 30 (2020) 11–16 A.A. Antonov et al. / Structural Integrity Pro edia 00 (2020) 00–0 0

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Fig. 2. Section of the I-line of the underwater gas pipeline on Uluu Aryy island, Hatassy village (1592.28 m).

Fig. 3. Section of the I-line of the underwater gas pipeline on Uluu Aryy island, Hatassy village (2798.56 m).

A section of the gas pipeline with a length of  30 m was observed sagging under the water 3555 m far from the Hatasskaya channel. The outer generating line of the pipeline was 0.2 m from the water surface. During the autumn inspection after the freeze-up period, the pipeline in this area was under the ice. The line-I maintenance area was also found on Bergehe Uehe island close to the right bank of the river. A distinct difference in the planned-high altitude position of the two pipeline ends was detected at the coupling place. After joining gas pipes, there will be a dangerous section that has a bend in the area of the welded joint, which is a stress concentrator. The planned-high altitude position of the gas pipeline is presented on Fig. 4. This graph demonstrates that the pipeline has a deflection due to sagging and seasonal bulging at the coastal slopes of the channel.