The Effect Of The Soil Dynamics Parameters On The Design Response Spectrum Of Site

Presently, many soil dynamics parameters are needed in the work ofseismic zonation, seismic microzonation and evaluation of seismic safetyfor important engineering sites. Some of these parameters should besurveyed in practice, and others should be confirmed from empirical dataor recommended. It is used to provided site-specific design parameters ofground seismic motion, such as the characteristic period of responsespectrum ( T_g ) and platform height ( α_max).In this thesis, some parameters have been changed to analyze thesensitivity that these dynamic parameters have effect on the result of thedesign response spectrum. The main works and achievements are asfollows:1. Introducing the history and some progress of the study on theeffect of site conditions on ground seismic motion and response spectrumat home and abroad, especially the research status of the effect of soildynamic characteristics on response spectrum. Point out the shortagenowadays and the significance of this research.2. Introducing the principle of the computer program forone-dimension equivalent linearization method of soil layers seismicresponse analysis in earthquake engineering field. Moreover, showing themerit and demerit of linearization method of soil layers.3. Introducing the equipment and test methods presently, andaccounting for the uncertainty of each parameter in brief.4. Based on three section plane of sign soil layer, the effect of soildynamics parameters (dynamic shear modulus ratio, damping ratio andshear wave velocity of soil) on the design response spectrum of soil withthree earthquake motion input of different intension. Stressed thesensitivity of three dynamic parameters on the characteristic period ( T_g )and the platform height ( α_max) of ground acceleration response spectrum.The results show that: First, the characteristic period decreasesgradually with the raise of dynamic shear modulus ratio. At the same timeplatform height raises gradually. Second, while the damping ratio of soilraises, the characteristic period lowers inconspicuous and the platformheight lowers evidently, therefore, the platform height of design responsespectrum is sensitive on damping ratio of soil. Third, with the raise ofshear wave velocity, Tg of design response spectrum lowers evidentlyand so does the α max of response spectrum. Consequently, the shear wavevelocity of soil should be survey in actual work, or else it can bringunacceptable tolerance.Furthermore, because of different earthquake motion intension, thesensitive extent of soil dynamics parameters on the characteristic period( Tg ) and platform height ( α max) of design response spectrum is influenced.In the end of this thesis, the main work and results are summed up.And the following work and future study are pointed out.