Dewatering Characteristics and Inflow Prediction of Deep Foundation Pits with Partial Penetrating Curtains in Sand and Gravel Strata
Round 1
Reviewer 1 Report
I have read with interest the paper entitled “Dewatering Characteristics and Inflow Prediction of Deep Foundation Pits with Partial Penetrating Curtains in Sand and Gravel Strata”. In my opinion, the paper fits on the scope of “Water”and the topic is interesting for the audience of this journal. However, changes and clarifications should be done before its publication.
Line 39: Why “however”? Please, rephrase these lines. Lines 40-43: It seems that the piezometric head is high because of the deposits. However, I think that it is high because it is a coastal aquifer. Line 47: In these situations (excavate overlying layers separated by aquitards) only bottom uplift occurs. Lines 51-52: It is not sure that settlements are conical. Please see: “Settlements around pumping wells: analysis of influential factors and a simple calculation procedure” General comment (lines 34-57): I would rewrite these lines. It is complicated to follow “the history” of the paper through them. Line 168: Please, indicate if the position of the hydraulic head that you mention refers to the depth. The same for the head in the confined aquifer. Line 215: “barrier effect”: Could you use another terminology? Generally, “barrier effect” is used to talk about the impact of an underground structure on the natural distribution of the groundwater flow. Line 354: Location of pumping wells: Did you check the effectiveness of the dewatering system with a numerical model? Line 236: Could you explain a little bit more about these four stages? Line 247: Why M is 36 m? You have established your solution for a specific configuration of the aquifer. Do you think that it would be useful in soils in which the structure is different?
Author Response
Dear Reviewer:
We acknowledge the careful review and comment suggestions from you. Base on the comments, the manuscript has been revised accordingly, and the specific revised portion is marked in blue in the revised manuscript. Following lists the major revisions and our responses to the comments, also the original comments are reproduced in blue italic for reference.
(1) Line 39: Why “however”? Please, rephrase these lines.
Response:
Thanks for your suggestion. The sentence has been rewritten. (see line 39- 43, page 1)
(2) Lines 40-43: It seems that the piezometric head is high because of the deposits. However, I think that it is high because it is a coastal aquifer.
Response:
Thank you for your valuable suggestion. The sentences have been rewritten. (see line 42, page 1)
(3) Line 47: In these situations (excavate overlying layers separated by aquitards) only bottom uplift occurs.
Response:
Thanks for your valuable comments. Bottom uplift failure and even water inflowing towards the excavation can occur in these situations. The sentences have been rewritten. (see line 50, page 2)
(4) Lines 51-52: It is not sure that settlements are conical. Please see: “Settlements around pumping wells: analysis of influential factors and a simple calculation procedure”
Response:
Thanks for your instructive suggestion. “ground settlements” may be more appropriate here. The sentences have been rewritten. (see line 56, page 2)
(5) General comment (lines 34-57): I would rewrite these lines. It is complicated to follow “the history” of the paper through them.
Response:
Thanks for your valuable comments. These lines have been rewritten. (see line 34-62, page 1-2)
(6) Line 168: Please, indicate if the position of the hydraulic head that you mention refers to the depth. The same for the head in the confined aquifer.
Response:
Thanks for your instructive suggestion. The position of the hydraulic head refers to the ground surface (bury depth) has been indicated. (see line 178-180, page 7)
(7) Line 215: “barrier effect”: Could you use another terminology? Generally, “barrier effect” is used to talk about the impact of an underground structure on the natural distribution of the groundwater flow.
Response:
Thanks for your instructive suggestion. The terminology “barrier effect” has been replaced by “blocking effect”. (see line 24, 64, 78, 139, 207, 231, 374)
(8) Line 354: Location of pumping wells: Did you check the effectiveness of the dewatering system with a numerical model?
Response:
Thanks for your instructive suggestion. To check the effectiveness of the dewatering system, the two stage dewatering simulation is carried out. (see line 390-403, page 15)
(9) Line 236: Could you explain a little bit more about these four stages?
Response:
Thanks for your instructive suggestion. These four stages have been explained in the revised manuscript as follow: (see line 252-257, page 9)
“stage I: groundwater withdrawals only come from aquifers inside pits and drawdown develops with no barrier influence; stage II: groundwater withdrawals come from aquifers inside and outside pits and drawdown is in influenced by the presence of barriers; stage III: groundwater withdrawals are supplied by outside aquifer only and drawdown−time curve is parallel to the no barrier condition; stage IV: pumping reaches the stable state and drawdown becomes constant.”
(10) Line 247: Why M is 36 m?
Response:
There are two reasons.
1) According to the hydrogeological conditions of the study area, the largest thickness of the aquifer is commonly ranging between 36 m and 40 m; several specific areas with ultra-thick aquifers need other construction method (Cao, 2019).
2) The growth rate of the water inflow in numerical model gradually slows down with the increasing M under the same bd (Mu/M) (since the longer wall induces more vertical flows and forms more drawdowns), whereas Thiem results keep the consistent growth rate (see equation 7). As M exceed 36 m, the growth rate of the numerical result will be inferior to that of the Thiem result, then β < 1 is given and Qd will decrease with the increasing M, namely, M = 36 m is a stationary point of the normalized distortion function.
Therefore, the reference value M = 36 m is taken.
Reference:
Cao C, Shi C, Liu L et al. Novel Excavation and Construction Method for a Deep Shaft Excavation in Ultrathick Aquifers. ADV CIV ENG 2019;2019:1-15.
(11) You have established your solution for a specific configuration of the aquifer. Do you think that it would be useful in soils in which the structure is different?
Response:
Thank you for your valuable comments. The aim of this study is to provide a method for predicting water inflow of deep foundation pits with partial penetrating curtains for a specific configuration of the aquifer in Fuzhou, China. In soils with different structure, uncertain deviations with varying degree may occur due to the various line type and imitative effect (refer to deviations in Figure 8 (b)). For the aquifers and soils in other region, the appropriate solution can be established refer to the procedure presented in this study. Moreover, the non-Dance flow in soils with high flow rates and the fissure flow in rock strata may not apply this procedure.
The manuscript has been resubmitted to the journal. We look forward to your positive response.
Reviewer 2 Report
See all comments in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer:
We acknowledge the careful review and comment suggestions from you. Base on the comments, the manuscript has been revised accordingly, and the specific revised portion is marked in blue in the revised manuscript. Following lists the major revisions and our responses to the comments, also the original comments are reproduced in blue italic for reference.
(1) It's not clear where the studied area is. It would be better to add a map.
Response:
Thank you for your suggestion. The map of the studied area has been added in the revised manuscript (shown in Fig.1). (see line 97, page 3)
(2) Line 78: I think "Thickness" and not depth
Response:
Thank you for your instructive suggestion. The sentence has been rewritten. (see line 85, page 2)
(3) Line 90: The specific storage (1/L); Storativity (dimentionless)?
Lines 117: What is Ss? Is the Storage Coefficient (Storativity - dimentionless) or Specific Storage (1/L)?
Line 157:?
Response:
Thanks for your careful examination. Ss is the specific storage (1/L), the sentence has been rewritten. (see line 99, 126, 147, 167)
(4) Line 172: 10E-5m/d is equal to 10E-10m/s. This is not a low permeability, but impermeable layers or very low permeability. It's the permeability of a clay.
Response:
Thank you for your good suggestion. The sentence has been rewritten. A very low permeability (10−5 m/d) is assigned to the hydraulic conductivity of the rectangle barrier in the model, and the “low permeability” is replaced by “impermeability”.
(5) Line 198: erosive phenomena? Explain better
Colombo, L., Gattinoni, P., Scesi, L., 2017. Influence of underground structures and
infrastructures on the groundwater level in the urban area of Milan, Italy. Int. J.
Sustain. Dev. Plann. 12 (1), 176–184.
Response:
Thanks for your instructive suggestion. The phenomena have been explained better in the revised manuscript referring to this suggested reference. (see line 182, page 7)
(5) Line 231: T is trasmissivity (ke) with e equal to the thickness of the aquifer. The hydraulic conductivity coefficient is the permeabilty k.
Response:
Thank you for your careful reading. The sentence has been rewritten. (see line 247, page 9)
(6) Line 304: Before showing the methodological scheme of the design, it would be better to present a scheme of the hydrogeological conditions of the area (piezometric lines, flow directions, etc.)
Response:
Thanks for your instructive suggestion. The hydrogeological conditions of the area have been presented in the revised manuscript (shown in Fig.9). (see line 338, page 12).
Unfortunately, the head monitoring data of the Fuzhou area is not available, piezometric lines and flow directions can not be drawn.
The manuscript has been resubmitted to the journal. We look forward to your positive response.
