## 3 Results and Discussion
### Typical Profile Analysis
#### 3.2.2 Typical Point Characteristics  
Comparison and analysis of the total displacement and von Mises stress extremes of the existing tunnel's measurement points in typical profiles for the four calculation conditions. 1. Analysis of total displacement at measuring points  
Figure 20 shows the comparison curves of the total displacement at the typical profile of existing tunnels under different working conditions. The total displacement change rule of measuring points in the MS1\(\sim\)MS5 profiles of the tunnel under the four calculation conditions is the same, and the extreme value of the typical measuring points of the upper and lower step blasting method excavation is the largest, followed by the upper and lower step static method, the CD blasting method, and the CD static method. Figure 20: _Cont._  
The total displacement of the arch measuring points U1 and U5 in the MS3 profile is the largest and the values of both profiles decrease symmetrically, with the settlement value of measuring point U1 being larger than the settlement value of measuring point U5. The total displacement extreme value of the upper and lower step blasting method's excavation measuring points, for U1 and U5, is 2.55 mm and 2.01 mm. The total displacement extreme value of measuring point D1 of the base plate tunnel structure is obvious in the MS2-MS4 profile settlement, with similar values; MS4-U1 is larger than MS2-U1, which is larger than MS3-U1. The total displacement extreme value of measuring point D5 of the base plate away from the tunnel structure is prominent in the MS2 and MS4 profile settlements, with MS2-U5 > MS4-U5, and the total displacement extreme values of measuring point D5 of the MS1, MS3, and MS5 profiles are smaller, but with similar values. The extreme values of total displacement of measuring points U1 and U5 in the excavation of the upper and lower step blasting method are 3.09 mm and 8.27 mm. Typical measurement points of the left and right side walls have similar total displacement extremes and the settlement is obvious in the MS2-MS4 profile, with similar values. The total displacement extremes of measuring points L1 and L5 of the upper and lower step blasting method excavation are 2.83 mm and 2.78 mm; the total displacement extremes of measuring points R1 and R5 are 2.84 mm and 2.72 mm. von Mises stress analysis at measurement points  
Figure 21 shows the comparison curves of von Mises stress extremes at typical profile measurement points for existing tunnels with different operating conditions. Figure 20: Comparison curves of total displacement extremes of typical profiles of existing tunnels with different working conditions: (**a**) arch top; (**b**) floor; (**c**) left wall; and (**d**) right wall. The von Mises stress extremes of the tunnel structure measurement points and the farthest end measurement points in the four calculation conditions' MS1\(\sim\)MS5 profiles have similar patterns. Figure 21: Cont. The von Mises stress increase values of the arch measuring point U1 are all negative increase values, and the negative increase value of the MS3 profile is the largest; the values of the upper and lower step blasting method and the CD static method are similar, and the difference between the upper and lower step static method and the CD blasting method is minimal; the negative change extreme value of the von Mises stress of the measuring point U5 of the CD static method is the largest and it is \(-\)887.42 kPa; the von Mises stress increase values of the arch measuring point U5 are all negative increase values, and the negative change extreme value is \(-\)887.42 kPa. The von Mises stress increase value are negative increase, the change value is small, and the values of different calculation conditions are similar, while the distribution of von Mises stress negative change extreme values is from \(-\)139.74 to \(-\)164.41 kPa.