# Study on Water Inrush Characteristics of Hard Rock Tunnel Crossing Heterogeneous Faults
## 5 Results
### Evolution Law of Water Inflow
#### 5.3.2 The Law of Change of Gushing Water with Time  
Figure 11 illustrates the temporal variation in water inflow over a transient analysis period set to 200,000 s, with focus on characteristic cross-sections located at x = 80 m within the damage zone and x = 90 m inside the fault core. In the damage zone, the water inflow experiences a decline from 0.79 m\({}^{3}\)/s to 0.23 m\({}^{3}\)/s as the calculation time extends from 0 to 200,000 s, reflecting a significant reduction of 70.9%. Conversely, within the fault core, the water inflow remains relatively stable throughout the simulation, with minor fluctuations around 1.21 m\({}^{3}\)/s. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Date**} & \multicolumn{1}{c}{**Water Inflow (m\({}^{3}\)/d)**} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \hline
3–14 March & 2982 & 4616 & 5127 & 6139 & 5319 & 4047 & 4714 & 7918 & 6172 & 14,185 \\
15–24 March & 9319 & 6538 & 9054 & 13,901 & 7527 & 11,910 & 11,717 & 11,828 & 9080 & 13,146 \\
25 March-3 April & 7685 & 15,258 & 9487 & 17,879 & 14,129 & 10,374 & 9580 & 15,126 & 15,925 & 15,944 \\
4–13 April & 17,465 & 8007 & 17,872 & 19,258 & 15,952 & 14,941 & 9429 & 15,038 & 16,000 & 13,758 \\
14–23 April & 14,547 & 13,946 & 16,666 & 14,516 & 12,627 & 22,196 & 18,952 & 17,769 & 20,489 & 217,787 \\ \hline
24 April-3 May & 18,594 & 18,978 & 20,050 & 17,009 & 17,817 & 18,897 & 24,132 & 17,218 & 18,985 & 17,706 \\
4–13 May & 17,017 & 19,254 & 17,180 & 18,755 & 18,297 & 16,654 & 17,843 & 19,418 & 19,267 & 22,196 \\
14–23 May & 13,952 & 17,769 & 20,489 & 21,787 & 18,594 & 18,978 & 20,050 & 15,009 & 15,817 & 16,897 \\
24 May– 2 June & 24,132 & 17,218 & 16,254 & 17,180 & 18,755 & 18,297 & 16,654 & 14,843 & 14,418 & 19,267 \\
3–12 June & 22,196 & 13,952 & 17,769 & 20,489 & 21,787 & 11,042 & 12,231 & 8807 & 8273 & 3248 \\ \hline
13–22 June & 16,344 & 8907 & 10,697 & 10,001 & 11,342 & 9665 & 14,762 & 10,880 & 10,032 & 8600 \\
23 June–2 July & 7915 & 9258 & 9774 & 10,765 & 10,156 & 9305 & 8564 & 9247 & 7635 & 8502 \\
3–12 July & 11,829 & 7865 & 8807 & 9354 & 7384 & 7504 & 17,232 & 15,456 & 12,437 & 13,338 \\
13–22 July & 11,637 & 10,539 & 9148 & 9765 & 8582 & 7541 & 7856 & 6519 & 9459 & 8258 \\
23 July–1 August & 7136 & 9236 & 6325 & 6880 & 9958 & 8058 & 8086 & 7057 & 5963 & 6250 \\ \hline
2–11 August & 6994 & 9313 & 10,576 & 8192 & 10,038 & 8505 & 9513 & 7796 & 7604 & 10,238 \\
12–21 August & 9294 & 9204 & 8657 & 9914 & 9283 & 9984 & 8605 & 7171 & 9511 & 8909 \\
22–31 August & 8959 & 9369 & 8771 & 9006 & 8013 & 10,730 & 8257 & 8256 & 7064 & 7407 \\
1–10 September & 4685 & 6802 & 6690 & 5720 & 7347 & 8623 & 7770 & 8510 & 8158 & 8465 \\ \hline \hline \end{tabular} The green shading data represents the daily water inflow at the tunnel face in the fault core.  
\end{table} 
Table 2: Daily water inflow field measurement data. Figure 10: On-site water inflow measurements recorded by flow meters connected to the pumping system between May and September. Figure 10 also displays the daily water inflow values recorded by the flow meter of the on-site drainage pump within the fault core. The daily water inflow data collected from the flow meter connected to the water pump are summarized in the Table 2. An analysis of both Table 2 and Figure 10 reveals that from early March to mid-April, as the tunnel face traversed the damage zone, there was significant short-term fluctuation in daily water inflow. Specifically, on 26 March, the inflow surged to approximately 15,000 m\({}^{3}\)/d, then decreased to around 7000 m\({}^{3}\)/d by 27 March. Conversely, from mid-April to early June, once the tunnel reached the fault core, the water inflow remained consistently high, averaging around 20,000 m\({}^{3}\)/d. This persistent high inflow necessitated a pause in tunnel construction for about 50 days.