Numerical Analysis Of Plane SH Wave Scattering

The main difference between large-span structures and general structures’ seismic designanalysis is that the large-span structures need to consider the spatial differences of earthquake motion.But we cannot study the effects of propagation along the horizontal direction of seismic waves whenincidenting vertically and ignore the effects in the horizontal direction of seismic waves to structures.Therefore, we underestimated the spatial differences of the earthquake motion. This article consideredanalysis method of scattering in the case of oblique incidence of SH-wave，calculated and analysedresult by the use of numerical methods. This would lay the foundation for further analysis oflong-span structure in considering spatial distribution of seismic response. Specific works was asfollows:(1) Free-field was analysed by using the transfer matrix method in the case of oblique incidence ofseismic waves. This result was taken as border region’s incident waves.(2) A numerical analysis method was presented to solve scattering problem in the case of obliqueincidence of seismic waves. The result of free field was taken as incident input, the displacement ofinner joints was calculated by using lumped mass explicit finite element method, and the displacementof joints of artificial boundary was calculated by transmission artificial boundary. The feasibility ofthe method was verified by the calculation of the free-field.(3) Scatter of semi-circular valley was analysed in the case of incidence of SH waves, and comparedwith M. D. Trifunac’s analytical solution. The effectiveness of the proposed method was verified. Thecharacteristics of the response of surface displacement in different scenarios angle was compared andanalysed. Then, the need to consider the oblique incidence was illustrated.(4) Finally, works in this paper were summarized and suggestions on further research were given.