Method for qualitatively judging water filling condition of karst cave in front of tunnel based on diffracted transverse waves

Abstract

The invention discloses a method for qualitatively judging the water filling condition of a karst cave in front of a tunnel based on diffracted transverse waves. The method comprises the steps of arranging an excitation point on a subway tunnel face for exciting seismic transverse waves; arranging a plurality of three-component detectors on one side wall of the tunnel behind the excitation point;exciting seismic transverse waves to the front of the tunnel face at the excitation point, and then receiving feedback seismic data in real time by each three-component detector, and transmitting theseismic data to a seismic recorder; carrying out interference wave elimination processing on the seismic data received by the seismic recorder so as to obtain diffracted transverse wave data and direct transverse wave data reflected by the karst cave; carrying out migration imaging on the obtained diffracted transverse wave data reflected by the karst cave so as to obtain position information of the karst cave; and qualitatively judging the water filling condition of the karst cave by analyzing the ratio of the energy of the diffracted transverse waves to the energy of the direct transverse waves. The position of the karst cave in front of the tunnel can be determined, the water filling condition of the karst cave in front can be qualitatively judged, and data support is provided for subsequent safe tunneling of the tunnel.

Description

technical field [0001] The invention relates to a method for detecting a karst cave in front of a subway tunnel, in particular to a method for qualitatively judging the water filling situation of a karst cave in front of a tunnel based on a diffraction shear wave. Background technique [0002] The excavation of hard rock subway tunnels usually adopts the mining method. During the construction of the tunnel, the karst cave is the key channel for serious geological disasters such as water gushing, water and mud inrush, and caving. Therefore, in order to ensure the safety of subway construction, it is particularly necessary to carry out corresponding advanced forecasting during the excavation process of subway construction. The existing research results and on-site practical experience show that there is a lack of a reliable, effective and easy-to-operate method and means in detecting the water filling of karst caves. For example, due to the influence of complex urban traffic r...

AI Technical Summary

Problems solved by technology

Existing data show that diffraction shear-wave imaging can detect and identify important subsurface structural information, such as broken zones, faults, pinch-out points, small-scale intrusions, and other discontinuous geological bodies, but diffraction shear-wave imaging cannot directly Used in tunnels, the reason is that due to the influence of interference waves, the diffracted shear waves reflected by the cave cannot be extracted from the received seismic data, and thus the water filling situation of the cave ahead cannot be accurately detected, which ultimately affects the subsequent safe excavation of the tunnel.

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