渤海常见土类剪切波速与埋深关系分析

Relationship between Shear Wave Velocity and Depth for Conventional Soils in the Bohai Sea Area

土层的剪切波速是岩土地震工程中重要的物理量,本文利用多年来在渤海海域地震安全性评价中积累的资料,研究了渤海常见土类剪切波速和埋深的关系。利用非线性最小二乘法,采用指数函数、一次函数、二次函数、幂函数、"幂函数+常数函数"、"幂函数+一次函数"6种回归模型对各类土的剪切波速和埋深的关系进行了回归分析,以拟合优度以及最小二乘拟合的误差平方和为评价指标对比了各种模型拟合效果的优劣。结果表明,"幂函数+一次函数"回归模型的拟合效果最好。此外,本文给出了该海域常见的7类土在此回归模型下的拟合公式的系数,以供工程中参考。

Shear wave velocity of soil layers is an important physical index in geotechnical earthquake engineering. Based on the experimental data accumulated over the years in the seismic safety evaluation research projects of the Bohai sea area, relationship between shear wave velocity and depth of conventional soils has been studied. In order to achieve the best fitting of experimental data, 6 regression models including exponential function, linear function, quadratic function, power function, power function combined with constant function, power function combined with linear function, have been used for regression analysis through nonlinear least square fitting method. The goodness-of-fit has been used as an index to evaluate the matching effect. The results showed that, the proposed form of function which combining power function with linear function has the best matching effect for experimental velocity data. Furthermore, the fitting coefficients of proposed function for 7 kinds of conventional soils in the Bohai Sea area have been presented for reference in engineering.