매설관의 3차원 동적응답거동에 대한 연구

Abstract

This research is for dynamic behavior of seismic wave using two different methods, 3D finite difference method and mode superposition method. The aim of the research is to compare these results about various boundary end conditions of buried pipeline and the results for this are as shown below. Based on the axial strains in the middle of the buried pipeline with free ends boundary condition, we have found that the axial strain obtained by mode superposition method is appeared higher 6.15% and that by 3D finite difference method is appeared higher 5.93% than that obtained by using the formula of Ogawa(2001). To compare the results of the mode superposition method with the 3D finite difference method, this research is analyzed with the sinusoidal wave of transmission velocity 300m/sec and 2000m/sec, respectively. We have studied the difference of the maximum displacement responses for axial direction obtained by the both methods in case that the transmission velocity is 300m/sec. The 3D finite difference method have shown higher values than the mode superposition method in degree of about 38.45%~40.71% for the free ends, fixed ends and fixed-free ends boundary condition. When transmission velocity is 2000m/sec, the maximum displacement response by 3D finite difference method have shown higher values than the mode superposition method in degree of about 9.14%~9.22% for the free ends and fixed-free ends boundary condition. However, at the fixed ends boundary condition, the maximum displacement response of the 3D finite difference method have shown lower values than the mode superposition method by 8.50%. At the boundary condition for the transverse direction of the pipeline in case that the transmission velocity is 300m/sec, the maximum displacement responses by the 3D finite difference method have shown lower values than the mode superposition method in degree of about 7.99% at the fixed ends, about 8.89% at the free ends, about 23.20% at the fixed-free ends and about 5.71% at the simply supported ends boundary condition. However, it has shown higher values about 7.45% at the guided ends and the supported-guided ends boundary condition both. When transmission velocity is 2000m/sec, it also is higher values in degree of about 39.38% at the free ends, about 10.35% at the fixed-free, about 22.02% at the guided ends, about 3.84% at the simply supported ends, about 16.83% at the supported-guided ends boundary condition. However, it has shown lower values about 20.62% at the fixed ends boundary condition. In the analysis of seismic response of the buried pipeline, thickness of the buried pipe doesn't really affect the dynamic behavior of buried pipeline even with the changes of ends boundary conditions of buried pipeline based on both the axial direction and transverse direction.