结合混合源面波与三分量频率谐振的浅震勘探在城市地质结构精细划分中的应用

Application of shallow seismic exploration combining mixed source surface waves and three-component frequency resonance method in fine detection of urban shallow geological structure

结合了混合源面波与三分量频率谐振的浅震勘探技术,综合了主动源面波探测精度高和被动源面波探测深度大的优点,同时增加了三分量频率谐振拟波阻抗比值这一参数进行综合推断解释,大大提高了探测的分辨率和准确性.采用该浅震勘探技术在成都天府国际生物城开展了浅层地质结构的精细化探测工作,快速获取了工作区60 m以浅地层结构的三维S波速度及三分量频率谐振拟波阻抗比值分布特征,利用波速与波阻抗的差异性,结合大量的工程钻孔资料标定,实现了对地层结构的精细划分,同时也证明了该浅震勘探技术在城市浅层地质结构精细化探测中的有效性.

The shallow seismic exploration combining mixed source surface waves and three-component frequency resonance method is a new method.This method combines the advantages of high detection accuracy of active source surface wave and large detection depth of passive source surface wave.At the same time,the parameter of three-component frequency resonance quasi-wave impedance ratio is added for comprehensive inference and interpretation,which greatly improves the detection accuracy and resolution.This new method was used in the shallow geological structure exploration of Tianfu International Biological City in Chengdu city.The 3D distribution characteristics of S-wave velocity and pseudo-wave impedance ratio of 0~60 m geological structure were obtained quickly.The fine division of stratum structure was realized by using the difference between wave velocity and wave impedance and combining with a large number of engineering borehole data calibration.It is also proved that this new method is effective in fine detection of urban shallow geological structure.