A Creative Method for Execution of Five Connected Pipelines in Crossing of River

To transfer potable water from north to the Khoramshahr port in southwestern Iran to meet urban and agricultural demands (where???), a combined unit of five carbon steel pipes, 1600 millimeters in diameter, had to cross the Karun River bed. Karun is the biggest river in Iran. The project location was 12 meters deep and 150 meters wide. This report describes the method used to complete this major pipeline installation. Pipes with the total required length were assembled in a dry dock. One-stage sinking was planned; hence, all pipes were connected to each other by steel structures forming one combined unit. To keep pipes from floating while being lowered to the river bed, sand bags were attached to the middle section of pipes and two air bags were placed on each side of the connected pipe unit. Also, to increase the accuracy of positioning in the face of river current, the pipe unit was anchored by cables. Four winches tensioned anchoring cables and controlled the position and alignment of pipe unit during the sinking maneuver. The unit was submerged by filling pipes in specific sequences. The sinking maneuver was modeled by ANSYS software.