Interfacial Separation Mechanism and Mechanical Response of Bimetallic Composite Pipes Under Strike-Slip Fault Movement

Abstract To investigate the interfacial separation mechanism and mechanical response of bimetallic composite pipes under stratum fault movement, a pipe–soil coupling model under stratum fault displacement was established. The effects of strike-slip fault displacement, liner wall thickness, stratum elastic modulus, and internal pressure on the interfacial separation and mechanical behavior of composite pipes were systematically studied. The results indicate that: the liner deformation increases with fault displacement and elastic modulus, but decreases with increasing liner wall thickness, while internal pressure shows opposite effects on liner deformation at both sides of the fault; the interfacial separation increases with fault displacement, but decreases with wall thickness, stratum elastic modulus, and internal pressure; and the axial strain of the liner increases with fault displacement and elastic modulus, but decreases with increasing wall thickness. Notably, low pressure can reduce compressive strain by 33.33%, while high pressure may increase liner strain.