A Dynamic Modeling Approach to Predict Water Inflow during Karst Tunnel Excavation
Round 1
Reviewer 1 Report
This work adopted the conduit flow process (CFP) model to predict the water inflow rate (m3/d) of the karst tunnel, and the prediction results are better than the MODFLOW method. I have some major concerns about the theoretical part (especially the unit of parameters) and minor comments about the overall style.
1. Please give the full name of SWMM and MODFLOW.
2. Please explain the meaning of duality (it might imply the karst matrix and karst conduit, right?)
3. Line 113, "DK234+506-DK243+535", could you explain these numbers?
4. You should add the unit of Q and t (might be L/s and d, respectively) to Fig 2a. Please adjust ALL the font sizes in your figures as much as possible (if appropriate). Sometimes they are too small!
5. MAJOR part: Section 3.1. In Eq. (1), the second sub-equation, why fm is evaluated at 0? The water head has a unit of [Length], right? If so, the K and D in Eq. (1) should have the unit of [Length/Time], which should be known as the hydraulic conductivity, instead of the permeability because permeability always has the unit of [Length2]. Please correct your terminology. Next, I guess the correct formula for D should be D = ((d2/12)/m)*(rg) where m is the dynamic viscosity (it can be converted to the kinematic viscosity n by dividing the density r). In other words, the d3 should be d2 in your expression. Please check the unit consistency. Finally, if the above units are consistent, then the unit for aex should be 1/m/s, instead of m2/d in Table 2. Please check.
6. Does Eq. (3) require specific units of the input parameters? Since I have noticed that you use the logarithmic function, which implies that unless the input for log() is dimensionless, the expression would require specific units. Please check the units and specify them. One simple calculation with real numbers would help.
7. Line 148, "hc" is not the subscript.
8. I cannot relate Eqs. (2)(3)(4) to Eq. (1). Also, the CFP model SHOULD be much more complex than the four presented equations. Why do you give these four equations here?
9. Figure 5. What does the number 1-9 in this figure represent? You should explain it.
10. Figure 11. How do you obtain the observed values?
11. The form of your Eqs. (6)(7) cannot be correct. There shouldn't be a subscript ", i" in your mean values with a bar on top. In fact, Eq. (7) is similar to the Pearson correlation coefficient, see Pearson correlation coefficient - Wikipedia. Please correct them accordingly.
12. There are also some papers about the water abundance prediction from water inflow rate and study of water inrush accidents by physical laboratory experiment, please mention them as well.
Wang, Z., Zhang, Q., Shao, J., Zhang, W., Wu, X., Zhu, X., 2020. New Type of Similar Material for Simulating the Processes of Water Inrush from Roof Bed Separation. ACS Omega 5, 30405–30415. https://doi.org/10.1021/acsomega.0c03535 Zhang, Q., Wang, Z., 2021. Spatial prediction of loose aquifer water abundance mapping based on a hybrid statistical learning approach. Earth Sci Inform. https://doi.org/10.1007/s12145-021-00640-3Comments for author File: 
Comments.pdf
Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
Nice work!
Author Response
Thank you for your acknowledgment and recognition of our research work, we will keep engaging in relevant research projects and we are looking forward to your review comments if there is an opportunity in the future!
Reviewer 3 Report
The manuscript is well written and organised. It applies a mathematical model- CFP to simulate the water inflow into the karst tunnel. The model sounds more efficient than the MODFLOW model for the karst aquifer and the execution of tunnels. The abstract is concise. Some remarks that can improve the manuscript. The title should be shorter and appellative. The introduction should give more literature data about the use of mathematical models on karst aquifer and the discussion should explore better the use of this model and others in the literature.
Author Response
Thank you very much for your comments. The title of this paper has been changed to “A dynamic modeling approach to predict water inflow during karst tunnel excavation” in “Line 2”. The literature data have been enriched in introduction part and the discussion part has been reedited.
Reviewer 4 Report
Thanks for your interested work
Author Response
Thank you for your acknowledgment and recognition of our research work, we will keep engaging in relevant research projects and we are looking forward to your review comments if there is an opportunity in the future!
Round 2
Reviewer 1 Report
The revision was okay.
