Modified image algorithm to simulate seismic channel waves in 3D tunnel model with rugged free surfaces

Li, Hui; Zhu, Peimin; Ji, Guangzhong; Zhang, Qiang

doi:10.1111/1365-2478.12351

Cited by 10 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The velocity of the acoustic wave is 340 m/s. The numerical simulation and measured data by several scholars [26,28] also prove that the tunnel seismic data contain surface waves. According to these rules, it is considered that symbol A denotes the direct P-wave, B the surface wave, and C the acoustic wave.…”

Section: Drilling Hole Descriptionmentioning

confidence: 63%

Tunnel Concealed Karst Cave Joint Detection by Tunnel Seismic and Transient Electromagnetic

et al. 2022

Lithosphere

View full text Add to dashboard Cite

The water-rich giant karst cave is the risk source of tunnel construction in the karst area. To reduce the risk of tunnel construction, it is necessary to accurately explore the spatial distribution range of the karst cave in the direction of advance and both sides of the tunnel. Reflection seismic and transient electromagnetic (TEM) are the primary geophysical tools for tunnel advanced prediction; they have strengths and weaknesses. The tunnel seismic can only describe the boundary interface between cave bodies and surrounding rock in the direction of advance. Although the TEM method can detect the spatial distribution range of cave bodies, the inversion results depend on the initial resistivity model. The single method is insufficient to describe the spatial distribution of cave bodies. To overcome the shortcoming of a single method, we developed tunnel seismic and TEM joint detection of karst cavern and established a complete data processing flow. The tunnel seismic migration profiles can describe the interface between the karst cave and surrounding rock in the direction of advance. We put forward a reasonable initial model: (1) the layer’s thicknesses are determined by the impedance interface from the tunnel migration data; (2) the initial resistivity values are determined from the pilot hole and prior geological data. Comparison of the inversion results of different initial models of tunnel face horizontal line data proves that the proposed initial model method can reduce multisolution, save calculation time, and improve inversion accuracy. The multidirectional TEM inversion profiles can describe the spatial distribution of the giant cave. Combined with the results of tunnel seismic and TEM, the interpretation errors can be reduced and the extension of the karst cave can be delineated. Later excavation results also verify the accuracy of the prediction results.

show abstract

Section: Drilling Hole Descriptionmentioning

confidence: 63%

Tunnel Concealed Karst Cave Joint Detection by Tunnel Seismic and Transient Electromagnetic

et al. 2022

Lithosphere

View full text Add to dashboard Cite

show abstract

“…The space step of the model was 0.4 m. A 500-Hz Ricker wavelet was used as the source, and the boundary conditions were selected as the perfectly matched layer (PML) boundaries. Due to the particularity of the tunnel conditions, free boundary conditions were set on the tunnel wall and the tunnel face, respectively, and the stress was set to zero [36]. The above conditions were used for the programming calculation.…”

Section: Methodsmentioning

confidence: 99%

A Semi-Automatic Coupling Geophone for Tunnel Seismic Detection

Wang

et al. 2019

Sensors

View full text Add to dashboard Cite

The tunnel seismic method allows for the detection of the geology in front of a tunnel face for the safety of tunnel construction. Conventional geophones have problems such as a narrow spectral width, low sensitivity, and poor coupling with the tunnel wall. To tackle issues above, we propose a semi-automatic coupling geophone equipped with a piezoelectric sensor with a spectral range of 10–5000 Hz and a sensitivity of 2.8 V/g. After the geophone was manually pushed into the borehole, it automatically coupled with the tunnel wall under the pressure of the springs within the device. A comparative experiment showed that the data spectrum acquired by the semi-automatic coupling geophone was much higher than that of the conventional geophone equipped with the same piezoelectric sensor. The seismic data were processed in combination with forward modeling. The imaging results also show that the data acquired by the semi-automatic coupling geophone were more in line with the actual geological conditions. In addition, the semi-automatic coupling geophone’s installation requires a lower amount of time and cost. In summary, the semi-automatic coupling geophone is able to efficiently acquire seismic data with high fidelity, which can provide a reference for tunnel construction safety.

show abstract

“…The model size is 50 m × 200 m × 50 m. The uniform grid spacing is 0.5 m. The time step is 3.5 × 10 −5 s. According to the conventional TSP geometry, two geophones ( Figure 3 , R-1, and R-2) are installed on the tunnel wall, and twenty-four shots are placed on one side of the tunnel wall ( Figure 3 shots). The shot interval is 1.6 m. Ricker wavelet is selected as the source wavelet, and the peak frequency is 500 Hz [ 20 ].…”

Section: Numerical Simulationmentioning

confidence: 99%

3-D Multi-Component Reverse Time Migration Method for Tunnel Seismic Data

Guan

Shao

Jiao

et al. 2021

Sensors

View full text Add to dashboard Cite

Migration imaging is a key step in tunnel seismic data processing. Due to the limitation of tunnel space, tunnel seismic data are small-quantity, multi-component, and have a small offset. Kirchhoff migration based on the ray theory is limited to the migration aperture and has low migration imaging accuracy. Kirchhoff migration can no longer meet the requirements of high-precision migration imaging. The reverse time migration (RTM) method is used to realize cross-correlation imaging by reverse-time recursion principle of the wave equation. The 3-D RTM method cannot only overcome the effect of small offset, but also realize multi-component data imaging, which is the most accurate migration method for tunnel seismic data. In this paper, we will study the 3-D RTM method for multi-component tunnel seismic data. Combined with the modeled data and the measured data, the imaging accuracy of the 3-D Kirchhoff migration and 3-D RTM is analyzed in detail. By comparing single-component and multi-component Kirchhoff migration and RTM profile, the advantages of the multi-component RTM method are summarized. Compared with the Kirchhoff migration method, the 3-D RTM method has the following advantages: (1) it can overcome the effect of small offset and expand the range of migration imaging; (2) multi-component data can be realized to improve the energy of anomalous interface; (3) it can make full use of multiple waves to realize migration imaging and improve the resolution of the anomalous interface. The modeled data and the measured data prove the advantages of the 3-D multi-component RTM method.

show abstract

Modified image algorithm to simulate seismic channel waves in 3D tunnel model with rugged free surfaces

Cited by 10 publications

References 26 publications

Tunnel Concealed Karst Cave Joint Detection by Tunnel Seismic and Transient Electromagnetic

Tunnel Concealed Karst Cave Joint Detection by Tunnel Seismic and Transient Electromagnetic

A Semi-Automatic Coupling Geophone for Tunnel Seismic Detection

3-D Multi-Component Reverse Time Migration Method for Tunnel Seismic Data

Contact Info

Product

Resources

About