Tunnel unfavorable geology advanced detection system and method based on high-frequency elastic waves

Abstract

The invention discloses a tunnel unfavorable geology advanced detection system and method based on high-frequency elastic waves. The system comprises a laser projection positioning device which is used for carrying out projection at a tunnel face, enabling a longitudinal measurement line and a transverse measurement line to be perpendicular and an intersection point to be located at the center of the tunnel face by controlling the projection focal length, and selecting measuring points on the longitudinal measuring line and the transverse measuring line; an automatic shock excitation device which is used for impacting the measuring points of the tunnel face along the measuring line direction and exciting seismic wave signals; a high-frequency detector which is used for collecting seismic wave signals transmitted by the measuring points of the tunnel face in the measuring line direction; and a data processing unit which is configured to perform filtering and inversion imaging on the received seismic wave signals to obtain a migration imaging oscillogram of the seismic wave signals, and obtain a detection result of unfavorable geology according to the migration imaging oscillogram. A minimum offset detection mode is established, automatic collection of high-frequency elastic waves is realized, and fine detection of a sub-meter small-scale unfavorable geologic body of the tunnel is realized.

Description

Technical field [0001] The present invention relates to the field of tunnel adverse geological advance detection techniques, and more particularly to a tunnel adverse geological advance detection system and method based on high-frequency elastic wave. Background technique [0002] The statement of this section is merely the background technology information associated with the present invention, which is not necessarily constituted in prior art. [0003] The tunnel advance geological forecasting is an essential link and important guarantee for tunnel safety. The superior geological forecast has become one of the processes of tunnel construction. One of the organic components of the tunnel construction geological survey work is the fine for the pre-tunnel survey results. Chemical, supplement, modification, and improvement. Elastic wavefringing is the most common geological forecast application of tunnel advance geological forecast applications, wherein the elastic wave reflection ...

AI Technical Summary

Problems solved by technology

The elastic wave method is the earliest and most commonly used geophysical method for the advanced geological prediction of tunnels. The elastic wave reflection has a sensitive response to the rock and soil with obvious differences in elastic wave impedance. The traditional elastic wave method can effectively predict Identify meter-level geological structures such as large-scale faults and broken zones, but the detection effect on small-scale geological bodies such as cracks and joints is not good

[0004] In order to avoid the interference of direct waves, ground roll waves, acoustic waves, and refracted waves arriving before the reflected waves, the offset distance (the seismometer distance of the geophone closest to the source is called the offset distance) must be large enough; or ultra-shallow objects, a large offset will cause the incident angle and reflection angle of the wave to be too large, that is, a wide-angle reflection will be generated, which will greatly reduce the intensity of the reflected signal

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