高精度分布式面波地震仪

High precision distributed surface wave seismograph

针对基于折射波或反射波法的传统地震仪存在对波阻抗差异较小的地下介质的分辨率较低的问题,设计一种高精度分布式面波地震仪。利用数字检波器对人工震源产生的面波信号进行采集,实现具有大动态范围、宽频带响应的面波检波阵列的设计。研制基于FPFA的地震信号采集节点,实现强干扰背景下地震信号的纯数字滤波与采集。此外,通过4G模块实现数据的无线传输和控制,从而提高探测效率。现场测试表明:在某高层建筑地基施工现场,仪器可实现对地震面波信号的高精度阵列采集,其探测反演结果与直接打钻结果基本一致,可有效验证其面波探测功能。

As the traditional seismometer based on refracted wave or reflected wave method has the problem that it has low sensitivity to underground media with less difference of wave impedance, a high-precision distributed surface wave seismograph was designed. It used digital geophone to collect surface wave signals generated by artificial sources, which avoided the disadvantages of analog geophones and thus realized the design of surface wave detection array with large dynamic range and wideband response. The FPFA-based seismic signal acquisition node was developed to achieve the pure digital filtering and acquisition of seismic signals under strong interference. In addition, the detection efficiency was enhanced by the 4 G module which achieved wireless data transmission and control. Field tests show that the instrument realizes the high-precision array acquisition of seismic surface wave signals at the construction site of a high-rise building foundation. The inversion result is basically consistent with the result of direct drilling, which verifies its surface wave detection function.