A continuous towed seismic data acquisition and correlation stack method for rapid detection of urban road

The rapid detection of urban road disasters has become an urgent problem. The continuous towed geophysical method is an important method for rapid general detection. Ground-penetrating radar and transient electromagnetic have realized continuous towed detection, but the seismic method cannot do it. The reflection seismic method has the advantages of deep detection depth and high resolution. To adapt to the rapid deployment of geophones on urban hardened pavement, a gravity geophone was designed to realize towed acquisition. However, the data acquisition is far from meeting the needs of large area rapid detection on urban roads. In this paper, a continuous towed seismic data collection method is proposed for the first time, that is, the vibration generated by the friction between the geophone base and the ground is used as the seismic source to realize the rapid data acquisition on the urban roads. When the vehicle-mounted seismic equipment is used and the required lateral resolution is 0.5 m, the continuous towed seismic data acquisition efficiency is about 5 km/h. Continuous towed seismic data has a low-resolution and low signal-to-noise ratio, and the real weak reflected signal is drowned by strong energy noise. To solve these problems, this paper proposes a correlation stack method to extract the stack section. When seismic data is collected with the continuous towed seismic equipment, the seismic source signal is not the approximate sharp plus signal, so the resolution of the extracted stack section is still low. Single detection results are difficult to distinguish near-surface structures. The continuous towed seismic acquisition method has a low cost and can realize the rapid repeated detection of the same survey line. The model data and measured data prove that the proposed data acquisition scheme and data processing method have the following advantages: 1) The continuous towed seismic acquisition method can improve the data acquisition efficiency, reduce the cost of data acquisition, and is suitable for large area rapid detection. 2) The correlation stack method can extract reflected signals with real weak energy. 3) Stack processing for multiple detection data can improve the resolution and enhance the energy of real weak signals. The continuous towed seismic data acquisition and the data processing method can realize the rapid inspection and detection of urban roads and has practical engineering application value.