## 5 Discussion (Engineering Applications)  
To verify the reliability of the research results, actual tests were carried out in this project. In combination with the actual work and research conditions, the technicians at the engineering site came to the conclusion through discussion and research that: if the seepage condition of the large-scale rock mass at the engineering site is to be obtained, the minimum research unit should be controlled in the range similar to the particle size of the rock sample and choose the smallest size possible within the range. Therefore, a cell size of 0.4 mm was ultimately chosen. This both meets the range requirements (0.35-0.8 mm) and ensures a smaller element model size. It should be noted here that the engineering site already has geological survey reports on various aspects of rock heterogeneity analysis, analysis of different strata, and hydrogeological conditions. If the specific conditions of large-scale in-situ rocks are to be obtained according to the small unit model, the size of the unit model should be within the range of the particle size of the rock sample that has been measured (0.35-0.8 mm). To ensure the accuracy and reliability, the size of the element model should be selected as small as possible, so that it can be finally calculated into the large-scale model (when the size is too large, accidental phenomena are prone to occur, and if a large number of accidental phenomena are calculated in the large-scale model, there will be a large error). After selecting the unit model size of 0.4 mm, the engineering field technicians discussed the research results of this manuscript in combination with the existing multi-faceted geological and hydrological survey reports. Due to the need to consider the heterogeneity of different rock layers, the regionality of water influx, and the effect of in-situ stress under this geological condition, the engineering site technicians classified the different rock conditions in the geological report, and based on the results obtained in this study (for example: if it is similar to the unit model taken in the study, the results of the manuscript will be applied; if it is different from the unit model taken in the study, the inverse calculation will be carried out through the study results of the manuscript), and the final comprehensive study has obtained the distribution of the water inflow distribution of the rock mass in the project. According to the distribution of water inflow, etc., the installation of drainage pipes and other equipment can be further guided. In the project, three test points were selected and monitored to verify the feasibility of the research conclusions. For the three areas with small, medium, and large water inflows in a state of no drainage, three measuring points, 1, 2, and 3, were set, respectively. According to the characteristics of the rock distribution and hydrological conditions in the area, combined with the aforementioned analysis of the seepage characteristic, the site layout of drainage equipment was carried out for the three test points (because drainage pipes and other equipment needed to be adjusted at any given time according to the actual situation on site, the layout of the drainage equipment plan is not provided). Then, the groundwater drainage operation began and the total water influx was recorded at different times. The water output at different time periods of the three measuring points before and after drainage was compared, as shown in Tables 12 and 13. Comparing Tables 12 and 13, it can be found that after the drainage equipment was arranged according to this method the amount of overflowing groundwater was greatly reduced. The maximum point only reached 9.55% (less than one percent), and the minimum point only reached 0.06%. Under different test points and different time conditions, the remaining water overflowing volume was minimal. This shows that the method effectively alleviated the problem of overflowing groundwater. This shows the feasibility of the conclusions of this paper.