【摘要】 基于天水黄土地区现场测试的539个地脉动测点数据,分析得到了其H/V频谱特征和场地卓越频率。结合该区59个钻孔编录和波速测试结果,运用1/4波长和覆盖层厚度与卓越频率统计等两种方法反演了该区黄土覆盖层厚度。结果表明,1/4波长法在黄土覆盖层较厚、且地层较为单一的Ⅲ、Ⅳ级阶地具有较好的适应性;覆盖层厚度与卓越频率统计法得出了较高精度的覆盖层厚度与卓越频率之间的幂函数关系,简化了剪切波速的影响,在整个研究区域具有较好的适应性。更多还原

【Abstract】 Based on the microtremor observation data of 539 measuring points in Tianshui,horizontal-to-vertical spectral ratio and the predominant frequency are analyzed.According to the geological records of 59 boreholes and shear wave velocity distribution,two methods including the quarter-wave length and statistical relationship between overburden thickness and predominant frequency are applied to inverse the overburden thickness.The results show that the quarter-wave length has great flexibility to the third and the fourth terraces with a thicker overburden and single stratum;high accurate formula simplifying the influence of shear wave velocity is drawn with the method of the statistical relationship between the overburden thickness and the predominant frequency;and it is suitable for the whole studied area.更多还原