## 1 Introduction
[11] proposed a precise and efficient method for transferring coupling data interfaces to describe the vibration response model caused by the fluid-solid coupling effect of oil and gas pipeline structures, thereby achieving a comprehensive calculation model for fluid-solid coupling vibrations in oil and gas pipelines. [PERSON] et al. [12] utilized a reduced order model to analyze the fluid-structure coupling in pipelines, employing the Bernoulli-Euler beam to represent the pipeline and a nonlinear oscillator to represent the fluid dynamics. The reduced order model successfully simulated the pipeline response spectrum while considering variations in flow rate parameters and random fluctuations. [PERSON] et al. [13] investigated the dynamic characteristics of buried water supply pipelines under earthquake actions, establishing a tube-fluid-solid coupling model for such scenarios and exploring stress responses of pipelines subjected to seismic dynamic actions. The current analysis of seismic failure mechanisms in cable-stayed straddling oil and gas pipelines, both domestically and internationally, is still imperfect as it only remains at the stage of finite element simulation analysis. Furthermore, there is a lack of experimental research conducted thus far. [PERSON] et al. [14] compared the seismic response results of long-span cable-stayed tube bridges considering linear and nonlinear problems, emphasizing the necessity to consider the nonlinear effects when analyzing the seismic response of such structures. Extensive research has been carried out on earthquake failure mechanisms in suspension pipeline span structures and highway cable-stayed bridges worldwide. In order to investigate the seismic failure and damage of a suspended cable pipeline span structure specifically, [PERSON] et al. [15] designed an experimental scale model for this purpose. They measured vibration and displacement under different pigging speeds and liquid deposition volumes using this scale model, subsequently establishing an empirical formula for the displacement-time curve based on their experimental data. [PERSON] et al. [16] utilized ANSYS software to simulate the seismic damage of a suspended-cable bridge in Changqing Oil Field and obtained the seismic performance of the structure in different directions of seismic propagation through nonlinear time-history analysis. [PERSON] et al. [17] investigated the failure mode of a long-span suspension bridge based on its design scheme and determined that the seismic failure mode of the tower is characterized by simultaneous double-plastic hinge failures, with plastic failure occurring simultaneously at both the tower body and bottom under longitudinal earthquake action. [PERSON] et al. [18] conducted modal and response spectrum seismic analyses on finite element models of four existing pipeline suspension bridges, revealing that locations near the end of suspension pipes experience higher stress levels under earthquake excitation, while support towers for some pipe bridges are prone to damage during high-intensity earthquakes. [PERSON] et al. [19] simulated the failure mechanism of pipeline joints under earthquake actions, analyzing deformation, stress, and strain characteristics of these joints while summarizing key causes leading to pipeline failures. [PERSON] et al. [20] developed a nonlinear numerical model to investigate the interaction between a large-diameter cylinder structure and soil mass and examined the dynamic response of the structure under recorded seismic waves. [PERSON] et al. [21] analyzed the dynamic response of underground pipelines during earthquakes, conducting numerical simulations of underground pipelines subjected to uniform 3D seismic activation using the mass method, ultimately capturing pipeline displacement, acceleration, and stress responses under such activation. Currently, there is limited research on the seismic failure modes of cable-stayed pipeline bridge structures, primarily in comparison to other types of span structures. [PERSON] et al.