| A numerical scheme is used for simulation of SH wave propagation through three different media: soil, a semi-circular flexible foundation, and a structure. The response is studied for two types of input: monochromatic steady-state wave and half-sine pulse.; The steady-state solution is presented for the example of the Hollywood Storage Building for two angles of incidence and for two different foundation stiffness. The displacement and strain amplitudes for the flexible foundation are generally larger than the amplitudes for the rigid foundation, except in the frequency range close to the natural frequencies of the building on a fixed base.; The transient response to a half-sine wave is analyzed with emphasis on three aspects of the problem: (1) Energy distribution. (2) Response at the contacts. (3) Response when the soil is nonlinear.; It is shown that the distribution of the maximum energy in the building and the scattered energy from the foundation are invariant with the duration of the pulse. Also, the input energy reaching the foundation is independent of the angle of incidence. The results of the energy distribution are illustrated for the Hollywood Storage building and the Holiday Inn hotel in Van Nuys, both in the Los Angeles metropolitan area.; The response at the contacts (soil-foundation and foundation-building) is studied for the Holiday Inn hotel for four angles of incidence and three foundation stiffness. The results are presented as normalized average displacements and as functions of dimensionless frequencies.; The constitutive law of nonlinear soil is assumed to be ideally elasto-plastic. Three levels of nonlinearity are considered, and the energy distribution and the distribution of the permanent strain are shown graphically for the above-mentioned two buildings.; Through analysis of the response at the contacts, it is shown that the response in the presence of small and intermediate nonlinearity generally does not differ appreciably from the linear response. There are significant differences between the response experiencing large nonlinearity and the linear response. |
