## 3 Detection Technology of Adverse Geological Bodies
### Borehole Multi-Source Data Fusion Analysis Method  
#### 3.2.1 Analysis of Extension Range of Structural Plane  
After acquiring accurate borehole optical imaging, borehole radar and borehole directional acoustic scanning data, the structural plane inclination, inclination and ductility steps are as follows:  
Acquire the digital borehole wall image, analyze the sine curve of the structural plane intersected with the borehole, and calculate the inclination of the structural plane intersected with the borehole.  
The borehole radar time profile is mapped, and the depth correction is carried out to find the radar profile image corresponding to the structural plane.  
Analyze the radar profile image, if the echo curve is the upper and lower wings of regular open scissors, use the relationship (9) and relationship (10) to estimate the wave velocity of rock and soil near the structural plane \(\
u_{i}\) and dielectric constant \(\varepsilon_{r}\).  
The approximate extension area of the structural plane is determined through the radar time profile of the structural plane. For the problem of the extension area of the structural plane, it is necessary to distinguish the types of radar time profile of the structural plane, including the radar time profile without pinch out and the radar time profile with pinch out. In the radar time profile with a pinch out structural plane, in addition to the reflected signal of the structural plane, sometimes the scattered signal at the tip of the structural plane can also be observed. However, in either case, an echo attenuation point or pinch out scattering point can be found as the minimum estimate of the extension of the structural plane; that is, the structural plane extends at least to this point, and the two-way travel time of the echo at this point is recorded as \(t_{\text{nip}}\).  
In order to determine the actual position of the point in the radar time profile, it is also necessary to deduce the migration formula. Set the structural plane inclination as \(\theta\). The antenna distance TR in the borehole is d, and TE is h. Assume that the unknown CE length is s and the reflection angle is \(\varphi\), then the radar echo propagation distance l is as follows:  
\[l=l_{1}+l_{2}=\
u_{i}t \tag{9}\]  
Among  
\[l_{1}=\sqrt{\left(s\cos\theta\right)^{2}+\left(s\sin\theta-h\right)^{2}} \tag{10}\]  
\[l_{2}=\sqrt{\left(s\cos\theta\right)^{2}+\left(s\sin\theta-h-d\right)^{2}} \tag{11}\]  
\[s=\frac{h\sin(\theta+\varphi)}{\cos\varphi} \tag{12}\]  
Figure 7: Schematic diagram of dynamic survey project area.  
\[\varphi=\arctan\frac{d\tan\theta}{2h+d} \tag{13}\]  
Since h >> d, it is generally considered that l\({}_{1}\approx\) l\({}_{2}\), so the position coordinates (x, y) of the radar wave at the reflection point of the structural surface can be obtained as  
\[x=s\cos\theta \tag{14}\]  
\[y=OR+d+h-s\sin\theta \tag{15}\]  
Among  
\[s=\frac{v_{i}t}{2\sqrt{\cos^{2}\theta+\left(\sin\theta-\frac{\cos\varphi}{\sin (\theta+\varphi)}\right)^{2}}} \tag{16}\]  
\[\varphi=\arctan\frac{d\tan\theta}{2h+d} \tag{17}\]  
The actual position of any echo point in the radar time profile can be determined by relationship (16) and relationship (17). Therefore, when the measured two-way travel time of the echo at the echo attenuation point or the pinch out scattering point is t = t\({}_{\rm{nip}}\), the approximate extension range of the structural plane is also determined by calculating the actual position of the point.  
Based on the above calculation results, the occurrence and extension of a structural plane can be obtained. As shown in Figure 8, the occurrence of structural plane and the approximate extension area can be obtained.