新疆乌鲁木齐地区vS30经验估计研究

从新疆乌鲁木齐市2004—2015年得到的841个钻孔中选择深度达30 m以下且钻孔资料记录完整的有效钻孔123个，通过计算5~30 m范围内不同深度的等效剪切波速，分别利用线性拟合、二次拟合和三次拟合对各深度v_S（d）及其v_S30进行拟合。通过对比发现，三个方程的拟合误差都随深度的增加而减少，且三次拟合方程的误差始终小于同深度的线性拟合和二次拟合方程，因此推荐使用三次拟合方程来估计新疆乌鲁木齐市钻孔的v_S30值。同时将此结果和Boore的结果进行比较后发现，不同深度处的等效剪切波速v_S（d）和v_S30具有地域差异性；Boore得到的结果在钻孔深度小于20 m时明显高估v_S30值，拟合曲线偏离实际数据点较远，所以本文拟合结果更适用于新疆乌鲁木齐市。综合比较可知，三次拟合得到的研究结果可以为新疆乌鲁木齐市钻孔深度不足30 m的地区求解v_S30值提供参考。最后，利用新疆克拉玛依市2004—2015年钻孔资料检验三个拟合公式对克拉玛依市的适用性，发现深度越接近30 m，误差越小；线性模型和二次模型相对来说比较可靠，平均误差接近于0，并且对深度大于10 m的钻孔有高估现象；三次模型相对来说误差比较大，并且几乎在所有深度都有低估现象。

Empirical Estimation of vS30 in Urumqi Area of Xinjiang

In this study, 123 effective drilling holes in Urumqi, Xinjiang, were selected from 841 drilling holes obtained during 2004-2015. The boreholes were below 30 m and recorded well. Through the calculation of equivalent shear wave velocities at depths of 5-30 m, the regression equation coefficients were separately obtained by linear fitting, square fitting, and cubic fitting. By comparison, it was found that the fitting error of the three equations decreased with the increase of depth, and the error of the cubic term was always less than those of the linear equation and the square equation at the same depth. Therefore, in this paper, the cubic equation is suggested as an empirical formula to estimate the v_S values of boreholes in Urumqi area. By comparing the results with the results of Boore, it is shown that the equivalent shear wave velocity v_S(d) and v_S30 at different depths have regional differences. The research results in this paper can provide references for solving the v_S30 of boreholes with depths less than 30 m in Urumqi, Xinjiang. Finally, the applicability of the three fitting formulas to Karamay is tested using borehole data in Karamay from 2004 to 2015. It is found that the closer the depth is to 30 m, the smaller the error. Moreover, the linear model and the square model are relatively reliable, with an average error close to 0, and the boreholes at depths greater than 10 m are overestimated. The cubic model features a relatively large error and its results are almost underestimated at all depths.