Structural behavior of large diameter prestressed concrete cylinder pipelines subjected to strike-slip faults.

Effective identification of damage characteristics and failure modes for buried pipelines subjected to fault movements is crucial for early design and disaster assessment. In the preceding companion paper, the structural responses of large-diameter prestressed concrete cylinder pipeline (PCCP) subjected to fault displacement were initially investigated under the condition where faulting crosses pipe barrel vertically, and the deterioration process and failure modes were summarized. However, the structural responses of jointed pipelines are closely tied to faulting parameters. In this paper, a study on the location and angle of the fault plane is conducted, and the damage response and failure modes of large-diameter PCCPs are analyzed in detail and compared. The results show that strike-slip fault movement causes pipeline movement through pipe-soil interaction, and the fault displacement is accommodated by several pipe segments for the large diameter-to-length ratio PCCPs. When the fault plane crosses the pipe segment at an acute angle, the primary failure modes include material damage to the pipe joints and barrel, as well as the risk of joint leakage. Material damage occurs at the joint when the fault plane passes through the PCCP joint. Given the mechanical properties and seismic resilience of PCCPs, it is advisable to avoid faulting at acute angles crossing pipeline joints. This work focuses on the structural behavior of segmented composited PCCPs crossing a fault, aiming to predict pipeline damage and failure. The findings contribute to a comprehensive understanding of the failure modes, damage characteristics, and disaster evaluation of PCCPs under strike-slip fault conditions.