海洋浅层土质剪切波速与深度的关系分析

Analysis on the relationship between shear wave velocity and depth of offshore shallow soils

剪切波速是工程场地地震安全性评价最重要的参数之一。应用测试的大量海洋浅层土质的剪切波速数据,利用最小二乘法通过三种模型探讨了不同土质类型的剪切波速与深度的关系,给出了不同土质类型的剪切波速与深度拟合最佳的统计公式。并与《构筑物抗震设计规范》的推荐公式在某一海域工程场地的测试结果进行对比分析,结果表明:本文所建立的统计公式对剪切波速的预测效果明显好于规范所推荐的统计公式。所推荐的海洋不同土质类型的剪切波速与深度间的统计公式,可供无波速测试的海洋工程场地使用。

The shear wave velocity of soils is one of the most important parameters in the field of geotechnical earthquake engineering. Based on the tested data of shear wave velocity of shallow soils from lots of offshore boreholes,the best regression equations of shear wave velocity and depth of soils including cohesive soils and granular soils are established by using three statistical models. The predicted shear wave velocity of soils with recommended equations is compared with the results of formula in the Chinese design code for earthquake resistance of special structures （GB50191-93）in a certain borehole. It is indicated that the fitting accuracy of recommended equations is better than that of formula in design code. Therefore,the recommended regression equations of shear wave velocity and depth of offshore shallow soils can be used for offshore site investigations, whose shear wave velocities are not tested.