Seismic Site Response Analyses of Bay of Campeche Clay Using Predicted Dynamics Soil Properties

摘要

Seismic site response analyses are an important first step in the seismic evaluation of fixed offshorernplatforms in the Bay of Campeche. This analysis is used to estimate ground motions for the development ofrndesign response spectra, dynamic stresses, strains, and displacements within the soil profile and liquefactionrnhazard analyses. Seismic site response analyses of a clayey deposit located in the Bay of Campeche isrnperformed using predicted dynamic soil properties, including the in-situ shear wave velocity based onrnempirical correlations developed for the Bay of Campeche clay, the shear modulus reduction curves and thernmaterial damping ratio curves based on equations also developed for the Bay of Campeche clay. The mainrnobjective of the study is to evaluate the effect of using predicted modulus reduction and material dampingrnratio curves on the design acceleration spectrum at the depth of maximum soil-pile interaction. Site responsernanalyses is also performed using other generic modulus reduction and damping curves presented by Vuceticrnand Dobry (1991), and Darendeli (2001).The spectral acceleration amplitudes are underestimated when therncurves of modulus reduction and material damping ratio of Vucetic and Dobry (1991) and Darendeli (2001)rnare used in the site response analyses, and overestimated when the curves proposed by Taboada et al., (2017)rnare used. It is found when comparing the results using laboratory curves that at the depth of maximum soilpilerninteraction the maximum ground acceleration and the plateau of the design acceleration spectra arernover estimated by 4% when the predicted modulus reduction and damping ratio curves are obtained usingrnthe equations developed by Taboada et al., (2017).Therefore, it is important to use predictive equations ofrnmodulus reduction and material damping ratio curves developed specifically for the Bay of Campeche clayrnwhen dynamic laboratory data is not available to generate these curves.