Pipe laying with elastic bending and pipe floating pulling method in a pipeline directional drilling construction in 3 300 m crossing the Yangtze River

Horizontal directional drilling is an important construction technology for pipeline laying construction currently, which has been used widely in various industries all over the world. Because of the long crossing distance, the construction zone is hard to meet the one-time prefabrication demand of the pipeline. The usable part of 3 300 m directional drilling crossing construction zone of Yangtze River is only 1 km, and the amount of removal is huge to reach one-time prefabrication, and on the other hand, adopting the "double-jointing pipe" or "triplet-jointing pipe" construction methods would pose great risks to long distance backtow of pipeline. In order to ensure that the pipeline would be backtowed successfully in one time, it is important to adopt elastic laying, crossing road and crossing river measures for one-time prefabrication of long distance pipeline. After stress calculation of pipeline strength and multiple measurements on site, finally the prefabrication scheme of pipe laying with elastic bending and the pipe floating pulling crossing Meirengang River is adopted in the construction. The method in the land part prefabrication of 1 km pipeline and the implementation plan of 2 km pipeline floating pulling in the Meirengang River are realized. Practice show that this measure reduces the pipeline backtow force significantly, decreases the removal, and lays a foundation for pipeline to backtow successfully in one time. This measure provides an important reference to the future directional drilling crossing over long distance.