A Targeted Grouting and Water Blocking Method Based on Hydrological Tracer Testing and Its Engineering Applications
, Bo Zhang 2,*, Haiyan Li 1,2, Liping Li 1,3, Chunjin Lin 1,2, Zhenhao Xu 1,3, Guodong Zhao 4 and Junfei Han 4Round 1
Reviewer 1 Report
In my opinion the tropic and the experience results presented in this paper are very interesting and original. Unfortunately after a very good presentation of the tracer test carried out to identify karst network in the area under study, and the theoretical principles it is based on, it isn't definitely clear the engineering application of these results to grouting choices and materials. I think that this part of the paper needs to be write again with a better explanation of its relationship with the first part. Sometimes references to figures and formulas suffer of some mistakes and ask to be verified.
Author Response
Response to Reviewer 1 Comments
Manuscript: A targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications (No. Water-482091)
Authors: Yijie Zhang, Shugang Wang, Jing Wang, Bo Zhang, Haiyan Li, Liping Li, Chunjin Lin, Zhenhao Xu, Guodong Zhao, Junfei Han
Submitted to: Water
First of all, we would like to thank the editor and the reviewer for their constructive reviews and for improving the quality of our manuscript.
This document directly addresses all comments made by the reviewer, and explicitly reports the changes made in response to the reviews. The responses are in red.
Reviewer's comment:
In my opinion the tropic and the experience results presented in this paper are very interesting and original. Unfortunately after a very good presentation of the tracer test carried out to identify karst network in the area under study, and the theoretical principles it is based on, it isn't definitely clear the engineering application of these results to grouting choices and materials. I think that this part of the paper needs to be write again with a better explanation of its relationship with the first part. Sometimes references to figures and formulas suffer of some mistakes and ask to be verified.
Response：Based on the reviewer’s comment, this article has been revised as follows.
1. In 2.3, we have provided a more detailed description of targeted grouting, which is described as follows.
The targeted grouting method is based on the parameters and curve form obtained by the hydrological tracer test, determining the form of underground runoff, the maximum runoff velocity, average runoff velocity, and the close relationship between the dosing point and the water point. The grouting material and grouting rate are selected by identifying the connection form of the underground runoff. If it is judged to be the pipeline connection, quick-setting and fast-hardening grouting material and high-speed grouting is selected. If it is judged to be crack-pipeline connection, polymer-cement grouting material with adjustable setting time is selected. It should be controlled to enter the crack without initial coagulation, and flow out of the crack with initial coagulation. Grouting rate can be adjusted according to grouting pressure. If it is judged to be crack type, single cement slurry grouting can be used first. The water cement ratio can be regulated by grouting pressure. According to the maximum runoff velocity, the grouting material can be designed to ensure the maximum retention rate at this flow rate. According to the close relationship between the injection point and the water point, the grouting volume can be predicted to avoid unrestricted grouting and waste of grout. The technology roadmap of the targeted grouting is shown in Fig.4.
Fig.4 The technology roadmap of targeted grouting
2. In 2.3.1, Grouting material optimization, the authors have added the relevant explanation of grouting material selection according to different connectivity, which is described as follows.
If the groundwater connection type is determined to be a fracture type, because of the small size range of fissures, especially in karst areas, the limestone strength is high and under certain grouting pressure, the grouts diffusion distance is difficult to meet the design requirements. Therefore, in order to ensure the grouting effect, it is necessary to select the grouting materials with long initial setting time, good fluidity and small particle size. The cement single slurry is preferred. If the fissure is too small, the superfine cement slurry with retarder can be used.
If it is determined to be a fracture-pipe type, the length and width of the connecting fracture determine the grouting material selected. In general, the width of the fracture is smaller and the flow velocity is smaller. Therefore, for this type of connection, the grouting material is not initially solidified when entering the fracture and reaches the initial solidification state when flowing out of the fracture. Because the length of the fracture is difficult to judge, therefore, for grouting material, its viscosity should reach a certain value, and the viscosity state should remain stable for a certain period of time. Under this condition, the grouts can flow to the main pipe under low pressure, and with the help of various admixtures, the slurry also has a certain anti-scouring ability. Therefore, the grouting material with adjustable setting time, strong injectability after initial setting and strong dynamic water scouring resistance should be selected, and the grouting material mix proportion should be adjusted according to grouting pressure and grouting running condition.
If it is determined to be a pipeline type, because the pipeline is larger and the flow speed is generally larger, the grouting fluid should reach the initial setting state in the borehole, the grouting material should quickly condense, and reach a certain strength value in a short period of time to prevent the scouring of dynamic water. Therefore, cement-sodium silicate slurry is the preferred grouting material with short initial setting time and short initial and final setting interval.
3. In 2.3.2, Determining the grouting rate, the authors have added the related discussion of grouting rate according to different connection conditions shown as follows.
If the connection type between the borehole and the water outlet is determined to be a fracture type, because the cracks are narrow and the grouting material is long in condensation, in order to ensure the grouting expansion distance in the cracks and loss to the invalid range, low-speed grouting is selected.
For the fracture-pipeline type, because the setting time of grouts has a certain adjustment space, the grouting rate should be adjusted according to the initial setting time of slurry. If the grouting rate is too high, the slurry will enter the pipeline before the initial setting. The slurry retention rate cannot be guaranteed. If the grouting rate is too low, the slurry will reach the initial setting state before entering the fracture, which may block the fracture. Therefore, the appropriate grouting rate should be selected according to the initial setting time.
If it is determined to be a pipeline type, the grouting rate should be increased according to the size of boreholes. The grouting volume can be increased by multi-pump combined grouting operation. If the grouting hole is too short, the length of grouting pipeline should be increased appropriately.
4. In 2.3.3, Grouting pressure, we have added the related discussion of grouting initial pressure according to different connection conditions, which is described as follows.
Initial grouting pressure control has different requirements for various types of connected forms. For fracture type, because of the good fluidity and long initial setting time of grout, the initial pressure of grouting is basically in a non-pressure state. Fracture-pipeline connection requires a certain pressure to ensure the continuous diffusion of slurry due to the initial setting state of slurry in the fracture. Therefore, a certain pressure should be guaranteed. The initial pressure of grouting should be determined according to the slurry running condition at the water point and material properties, but it should generally be less than 2 MPa. For pipeline type, because of the good penetration of pipeline connection, the initial grouting pressure is still small, generally less than 0.5 MPa, even if the quick setting and early strength grout is used.
5. In 3.3.1, we have additionally explained the reasons for the selection of grouting materials for various connected forms. The contents are as follows.
Formula 15
Fig.10 Variation of cement slurry viscosity with different proportions
Fig.11 Variation of viscosity of typical polymer cement and cement-water glass grouts
From Fig.10, it can be seen that the viscosity of single cement slurry increases slowly and the viscosity is only 12-22 Pa·s in 60 minutes. It is suitable for grouting cracks and is beneficial to long-distance diffusion. As shown in Fig.11, Polymer cement grouting material can reach 20 Pa. s in 60 seconds, and its viscosity increases slowly after 60 seconds. Therefore, it is suitable for grouting in fissure-pipeline channel, which can avoid blocking connected cracks and ensure that grouts with scouring ability enters the pipeline continuously. The viscosity of cement-water glass double slurry reaches 500 Pa s within 60 seconds, and the initial and final setting time is short. It is suitable for drilling grouting with pipeline connection and can ensure rapid plugging.
6. The calculation method of grouting rate has been added in 3.3.2.
7. The authors have carefully checked and verified the formulas and charts.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Review of the manuscript: A Targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications
I have now read the paper " A Targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications". The authors present a paper that described h hydrological tracer testing o determine the law of recharge and transport of groundwater using NaCl method.
It shows lots of work and improve the hydrological information on karst area and the tracers methods to develop. The results look reasonable and is certainly within the scope of the journal. However, in spite these test presentation are useful, especially in this geographical area, in some part the manuscript need to be revise and some concepts have to be improve. I send the comment in the document in attachment.
Some advices/food for thought for the revisions
Line 33- I think you can riformulate this part, because you repeat the same situation -in China - above.
Line 93: In Fig. 1 “Chiorine”. Need correction
Line 82, 227: when the Authors present the chloride ion selective electrode and the method to measure NaCl concentration. Did you consider the error of the measurement in your calculation? Do you think that could be important to consider the uncertainity of the measurement? If not, could the author explain why?
Line 268: In Fig. 8 i am not really sure to understand. On the left, in black is writtend, for example, +10m and then in light green we have +6-+8m close to the river, at a point that seems to be higher then -10m.
Then, for example, is written -28m between two value of the same color (-10 and -11.6m). How is possible? In the legend, is written that these numbers corresptnd to the elevation. This figure is not so clear…
Comments for author File: Comments.doc
Author Response
Response to Reviewer 2 Comments
Manuscript: A targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications (No. Water-482091)
Authors: Yijie Zhang, Shugang Wang, Jing Wang, Bo Zhang, Haiyan Li, Liping Li, Chunjin Lin, Zhenhao Xu, Guodong Zhao, Junfei Han
Submitted to: Water
First of all, we would like to thank the editor and the reviewer for their constructive reviews and for improving the quality of our manuscript.
This document directly addresses all comments made by the reviewer, and explicitly reports the changes made in response to the reviews. The responses are in red.
Reviewer's comment:
Review of the manuscript: A Targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications
I have now read the paper " A Targeted grouting and water blocking method based on hydrological tracer testing and its engineering applications". The authors present a paper that described hydrological tracer testing determine the law of recharge and transport of groundwater using NaCl method.
It shows lots of work and improve the hydrological information on karst area and the tracers methods to develop. The results look reasonable and is certainly within the scope of the journal. However, in spite these test presentation are useful, especially in this geographical area, in some part the manuscript need to be revise and some concepts have to be improve. I send the comment in the document in attachment.
Point 1:Line 33- I think you can reformulate this part, because you repeat the same situation -in China - above.
Response: We have deleted "especially in the karst areas of Southwest China, the underground space is complex" in line 33.
Point 2:Line 93: In Fig. 1 “Chiorine”. Need correction
Response: We have changed "Chiorine" to "chloride" in line 92.
Point 3:Line 82, 227: when the Authors present the chloride ion selective electrode and the method to measure NaCl concentration. Did you consider the error of the measurement in your calculation? Do you think that could be important to consider the uncertainty of the measurement? If not, could the author explain why?
Response: Good point! There are always errors in any measurement, either human error or equipment error. In our case, there are errors in the measurement of chloride ion concentration with chloride ion selective electrode. We also considered the influence of errors in the experimental measurement. We divided each sample into five parts and separately determined its chloride ion content during the experiment. The maximum and minimum values are removed, and the average value of the median value is taken as the final measured value. However, we are sorry that it had not been described in the last submission. Now We have elaborated in 2.1 in this revision.
Point4: Line 268: In Fig. 8 i am not really sure to understand. On the left, in black is writtend, for example, +10m and then in light green we have +6-+8m close to the river, at a point that seems to be higher then -10m. Then, for example, is written -28m between two value of the same color (-10 and -11.6m). How is possible? In the legend, is written that these numbers corresptnd to the elevation. This figure is not so clear
Response: We originally intended to define this drawing as a schematic, so there was a deviation in the elevation setting. In addition, due to the improper method used by the authors in processing the picture, the font of the picture was not clear. We apologized for this. We have revised the drawing and arranged the elevation as shown in the new figure.
Figure 8. Inferred underground runoff map.
Author Response File: Author Response.docx
