宽频拖曳式地震检波器的面波精细化探测成像

传统的主动源面波仪采用锥形速度型检波器,具有频带窄、纵向分辨率低的缺点。传统装置移动测点需人工手动逐一移动检波器,无法低成本快速采集高密度面波数据,横向分辨率低。文中提出适应于硬化路面的拖曳式地震面波数据采集方法,设计重力耦合加速度检波器,线性、阵列拖曳式检波器串结构,提出高采样以提高面波探测精度的方法,实现高密度、小道距、高采样率、宽频数据采集。分析模型数据和实测数据在不同采样率时的结果表明,高采样能压制噪声干扰增强低频能量,保证足够的探测深度;检波器采集的面波数据,能保证在足够的深度范围内精细地刻画速度层的变化,查明潜在的塌陷位置。将拖曳式地震检波器应用于城市道路塌陷探测,体现高效采集、精细探测的优势。

Surface wave fine detection imaging of broadband towed seismic geophones

The traditional active source surface wave instrument, employing tapered velocity geophones, suffers from narrow frequency band and low longitudinal resolution. Manual movement of geophones one by one in traditional devices for measuring points results in inefficiency and inability to rapidly acquire high-density surface wave data at low cost, leading to low lateral resolution. This paper proposes a towed seismic surface wave data acquisition method suitable for hardened roads. Linear string and array towed gravity-coupled accelerometer geophones are designed to achieve high-density data acquisition with small geophone spacing, high sampling rate, and broad bandwidth. Traditionally, the influence of sampling rate on the detection accuracy of surface waves has been neglected. This paper suggests that high sampling rates can improve the accuracy of surface wave detection. Analysis of different sampling rates between model data and measured data shows that high sampling rates can suppress noise interference, amplify low-frequency energy, and ensure sufficient investigation depth. The surface wave data collected by the geophones in this study enables detailed description of velocity layer variations and identification of potential collapse locations. The application of towed seismic geophone for urban road collapse detection showcases efficient acquisition and precise detection capabilities.