## 3 Mechanical Characteristic Analysis  
To obtain a more comprehensive understanding of the impacts of wetting-drying cycling and the lateral distance between holes and fissures on the mechanical properties of rocks, the mechanical properties of the three types of hole-fissured samples, after undergoing wetting-drying cycling, were analyzed and compared. Figure 3 presents the stress-strain curves of the complete sample and three hole-fissured structure specimens under uniaxial compression following wetting-drying cycling (labeled as No. a-b-c, where  
Figure 2: Test flowchart. 'a' denotes the pore distance, 'b' indicates the number of cycles, 'c' represents the sample number, and 'C' denotes the complete sample). Figure 4 illustrates the trends in the peak strength and average elastic modulus of the samples. Figure 4a-d represent the peak strength of the intact specimen and specimens with horizontal hole-fissure distances of 0 mm, 5 mm, and 10 mm, respectively. The figures indicate that as the number of cycles increase, the peak strength of all the samples exhibits a declining trend. After 10 and 20 cycles, the average peak strengths of the intact specimens were 57.45 MPa and 46.5 MPa, respectively. Compared to the initial average peak strength of 63.3 MPa at 0 cycles, the reductions were 9.2% and 26.5%. For the 0 mm specimen, the peak strength values of 49.7 MPa and 42.5 MPa after 10 and 20 cycles corresponded to reductions of 19.06% and 30.78%, respectively, relative to the initial value of 61.4 MPa. The 5 mm samples showed average peak strengths of 44.75 MPa and 36.8 MPa, representing decreases of 16.9% and 31.66% from the initial 53.85 MPa. The 10 mm samples exhibited average peak strengths of 30.3 MPa and 24.35 MPa, declining by 20.58% and 36.17% compared to the initial 38.15 MPa. Figure 4e-h illustrate the progressive changes in the elastic modulus of the intact specimen and hole-fissured samples under varying wetting-drying conditions. The elastic modulus was calculated from the linear portion (40-60%) of the stress-strain curve [36]. The results demonstrate a progressive decline in the elastic modulus with increasing cycles. After 10 and 20 cycles, the intact specimens had average elastic moduli of 8.29 GPa and 6.45 GPa, corresponding to reductions of 5.7% and 26.6% from the initial 8.79 GPa. The 0 mm sample decreased to 7.14 GPa and 6.11 GPa (reductions of 13.24% and 25.76%) relative to its initial 8.23 GPa. For the 5 mm sample, values of 6.74 GPa and 5.12 GPa reflected reductions of 15.93% and 36.16% from 8.02 GPa. The 10 mm sample showed  
Figure 3: Stress–strain diagrams of the specimens under varying numbers of cycles: (**a**) complete sample; (**b**) specimens with a lateral distance of 0 mm; (**c**) specimens with a lateral distance of 5 mm; (**d**) specimens with a lateral distance of 10 mm. elastic moduli of 5.54 GPa and 4.45 GPa, corresponding to decreases of 13.3% and 30.37% from the initial 6.39 GPa. Figure 4: The influence of wetting–drying cycles on the mechanical parameters of intact and hole-fissured specimens. (**a–d**) Peak stress, (**e–h**) elastic modulus. Analysis of the aforementioned data demonstrates that both the peak strength and elastic modulus of the specimens show a declining trend as the count of cycles rises. Specifically, the reduction in peak strength is more evident throughout the first 0-10 cycles than in the following 10-20 cycles. In contrast, the decline in the elastic modulus is more substantial during the 10-20 wetting-drying cycles. By comparing the peak strength and elastic modulus of three horizontal spacing specimens under 0 wet-dry cycles, it can be observed that with the increase of pore spacing, both the peak strength and elastic modulus of the specimens exhibit varying degrees of reduction. Specifically, when the lateral distance L grows from 0 mm to 10 mm, the peak strength decreases from 61.36 MPa to 53.85 MPa and 38.15 MPa, reflecting reductions of 12.24% and 37.83%, respectively.