Scattering And Diffraction Of Cylindrical Lined Cavities In Half-space Subjected To P & SV Waves

Many investigations of earthquake damage show that local site conditions have significant effects on ground motion; therefore, it can influence the distribution of earthquake damage. The purpose of study on the influence of local site conditions is to explain the reasons for the large amplifications and spatial variations of ground motion and to predict some features of the ground motion during future earthquakes. So site response analysis is one of the most important and attractive fields in earthquake engineering. Scattering and diffraction of earthquake waves by the underground lined cavities can affect the ground motion near the cavities, and further affect the buildings above the ground. Therefore, it is important to solve the problem both in theory and in engineering application.While using the Big-Circle-Method, that the surface of half-space is approximated by the cylindrical surface with very large radius, an analytical solution for the scattering of underground lined cavities subjected to the incident P&SV waves was derived in the thesis by the Fourier-Bessel series expansion technique. Furthermore, the effect of factors such as cavity's diameter, distance between cavities, incident wavelength, incident angle and lining's rigidity on the surface displacement was also analyzed. The results indicate that the existence of cavities affects the surface displacement of the half-space greatly. Frequency of the incident wave, distance between cavities and lining's rigidity are three important factors which affect the surface displacement.