Site conditions, including geotechnical properties and the geological setting, influence the near-surface response of strata subjected to seismic excitation. The geotechnical parameters required for the design of foundations include mass density (ρ), damping ratio (β_s), shear wave velocity (V_s), and soil shear modulus (G_s). The values of the last three parameters are sensitive to the level of nonlinear strain induced in the strata due to seismic ground motion. In this study, the effect of variations in soil properties, such as plasticity index (PI), effective stress (σ′), over consolidation ratio (OCR), impedance contrast ratio (ICR) between the bedrock and the overlying strata, and depth of soil strata over bedrock (H), on seismic design parameters (β_s, V_s, and G_s) was investigated for National Earthquake Hazards Reduction Program (NEHRP) site classes C and D, through 1D nonlinear seismic site response analysis. The Morris one-at-a-time (OAT) sensitivity analysis indicated that β_s, V_s, and G_s were significantly influenced by variations in PI, while ICR affected β_s more than it affected V_s and G_s. However, the influence of H on these parameters was less significant. It was also found that variations in soil properties influenced seismic design parameters in soil type D more significantly than in soil type C. Predictive relationships for β_s, V_s, and G_s were derived based on the 1D seismic site response analysis and sensitivity analysis results. The β_s, V_s, and G_s values obtained from the analysis were compared with the corresponding values in NEHRP to determine the similarities and differences between the two sets of values. The need to incorporate PI and ICR in the metrics for determining β_s, V_s, and G_s for the seismic design of foundations was highlighted.

场地条件，包括岩土工程性质和地质环境，会影响地震激发地层的近地表响应。为基础的设计所需的岩土参数包括质量密度（ρ），阻尼比（β_小号），剪切波速（V_小号），以及土壤剪切模量（G ^_小号）。最后三个参数的值对由于地震地面运动引起的地层非线性应变水平敏感。在这项研究中，土壤特性变化的影响，例如可塑性指数（PI），有效应力（σ），超固结比（OCR），阻抗对比率（ICR）基岩和上覆岩层，并在基岩（土层深度之间ħ），在抗震设计参数（β_小号，V_小号和ģ_小号）中研究了国家地震减灾计划（NEHRP）站点类的C和D，通过一维非线性地震现场响应分析。莫里斯一在-A-时间（OAT）敏感性分析表明，β_小号，V_小号和ģ_小号通过在变型中显著影响PI，而ICR影响β_小号超过它受影响的V_s和G _s。但是，H对这些参数的影响较小。人们还发现，在土壤性质的变化在土壤类型d比为土壤类型C.预测关系影响抗震设计参数的详细显著β_小号，V_小号和ģ_小号是基于一维地震站点响应分析和敏感性分析得到结果。的β_小号，V_小号和ģ_小号将分析获得的值与NEHRP中的相应值进行比较，以确定两组值之间的相似性和差异。有必要将PI和ICR中的指标用于确定β_小号，V_小号和ģ_小号为基础的抗震设计得到了强调。