YANWei,TANGShan-jun,SUNShi-peng,et al.Application of Built-in Steel Pontoon Floating-aid Technology in Construction of Large Diameter, Super Long and Super Bending Steel Immersed Tube[J].China Water & Wastewater,2024,40(24):92-98.
Application of Built-in Steel Pontoon Floating-aid Technology in Construction of Large Diameter, Super Long and Super Bending Steel Immersed Tube
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第24期
Page:
92-98
Column:
Date of publication:
2024-12-17
- Keywords:
- steel pontoon; floating?aid; large diameter steel pipe; super long steel pipe; immersed tube
- Abstract:
- The pipeline with length of 438 m, diameter of 2.62 m, wall thickness of 28 mm and mass of 784 t in Nanning Yongjiang River diversion project, was successfully sunk in June 2019 with the external pontoon and airbag floating-aid technology for immersed tube. In the process, the airbag de- aeration is not timely and takes too much time, which increases the closure time of the channel. The external steel pontoon increases the area facing the flow, and the bearing water force of it acts on the crossing pipe synchronously, so it is necessary to allocate a large sinking force to ensure safe pipe sinking. In the process of rotating and straightening the river crossing pipe, the contact between the float wire rope and the pipe body produces ligature marks, which destroys the coating of the river crossing pipe. In view of the above problems, an improved scheme is proposed. The sinking force can be rationally controlled by using the method of built-in steel pontoon for immersed tube through model calculation, which can reduce the flow area in the process of large-caliber pipeline sinking, keep the steel pontoon away from the flow force, and greatly reduce the sinking weight requirement. The uniformity of the rope tension in sinking control is improved to a great extent, and the closure time is shortened during the sinking process. The built-in steel pontoon floating-aid is economical and safe for the integral immersed tube of large diameter and long distance in busy river section.
Last Update:
2024-12-17