走滑断层作用下管道应变解析计算方法的适用性

Applicability of analytical calculation methods on the pipeline strain under the effect of strike-slip fault

管道在断层错动作用下容易产生较大的位移,从而导致管道因较大的应变而失效,因此研究断层作用下管道的应变计算方法对穿越断层长输管道的设计与安全评估具有重要意义。理论解析计算方法计算简单、效率高,因而在长输管道的初步设计中应用广泛。简要介绍了Newmark-Hall方法、Kennedy方法及Karamitros方法 3种应用较为广泛的管道应变理论解析计算方法,并与有限元结果进行对比分析,从管道穿越角、管道埋深、土壤类型及管材类型4个方面讨论了3种理论解析方法在走滑断层情况下的适用性。结果表明:Newmark-Hall方法、Kennedy方法适用于分析管道穿越角β<45°且断层位错量较大时的断层错动影响;Karamitros方法在各种工况下均具有较好的适用性,尤其是当穿越角β≥45°时,前两种方法的适用性极其有限,应该选择模型相对复杂的Karamitros方法进行计算。

A pipeline is prone to large displacement due to the movement of faults, and consequently the pipeline fails under the effect of large strain. In order to perform the design and safety assessment of long-distance fault crossing pipeline successfully, it is of great significance to research the calculation methods on the pipeline strain under the effect of faulting. The theoretically analytical calculation methods are widely used in the preliminary design of long-distance pipelines owing to its advantages of simple calculation procedure and high efficiency. In this paper, three theoretically analytical calculation methods （e.g. Newmark-Hall, Kennedy and Karamitros） which are widely used for pipeline strain calculation were briefly introduced. Then, their calculation results were compared with those of finite element method. Finally, the applicability of these three methods in the environment of strike-slip faults was discussed from four aspects, i.e., the crossing angle of pipeline, the buried depth of pipeline, the soil type and the pipe steel type. It is indicated that both Newmark-Hall and Kennedy methods are suitable for the cases whose pipeline crossing angle （β） is smaller than 45° and fault displacement is larger. The Karamitros method is better applicable in all conditions. Especially in the cases with larger crossing angle （β≥45°）, the Newmark-Hall and Kennedy methods are less applicable, so it is necessary to select the Karamitros method whose model is more complex. （8 Figures, 1 Table, 15 References）