低温条件下在役管道不停输沉降的设计与施工

Design and Construction of Pipeline Immersing in Service at a Low Temperature

管道沉降施工过程中,管道暴露在大气环境中,如果昼夜温差过大,会在管道内产生轴向应力,威胁管道安全。文中以涩宁兰一线和涩宁兰二线沉降施工为例,介绍了在役管道低温条件下不停输沉降的受力计算方法、施工步骤及注意事项,并通过增加沉管过渡段长度、降低管道操作压力等措施,降低了管道沉管施工的轴向拉伸应力,确保了低温条件下管道沉降施工安全,使沉管施工安全、顺利实施。

During its immerstion,a pipeline in service is exposed to the atmospheric environment,and this will lead to the occurrence of an axial stress in the pipe because of a great temperature difference between day and night,threatening the safety of the pipeline. The method for calculating the force in service,construction procedures and precautions at a low temperature are brought forward in this paper,taking as in example the pipeline immersing during the construction of the first and second Se-NingLan lines. In order to ensure the safety of pipeline settlement construction at a low temperature,the measures,such as increasing the length of the transition of the immersed pipeline,lowering the operation pressure,were taken to reduce the axial tensile stress of the immersed pipeline,making the pipeline immersing construction perform safely and successfully.