Depth Regression Analysis of Soil Shear Wave Velocity in Tianjin Urban Region

The shear wave velocity data of 2 212 sets of different soils of 78 drilling wells in Tianjin urban region were analyzed using mathematical statistics method. The optimal regression formulas of shear wave velocity were obtained in the case of considering and ignoring soil types. Then the empirical formulas were used to estimate the shear wave velocity of different depths in the actual drilling, and the estimated results were analyzed basing on the measured results. The results show that, an obvious difference between the correlation of shear wave velocity and soil depth of main soil types are existed in Tianjin urban region, in which the correlations of clay, silt and silty clay are the best, followed by siltstone and fine sandstone, and artificial filled are the worst; the fitting accuracy of polynomial models are the highest in all relationships between shear wave velocity and soil depth of main soil types; the given empirical relationships of shear wave velocity and soil depth of different main soil types are accurate and reliable, and they can be used to calculate the shear wave velocity of main soil types in Tianjin region.