Assessing Susceptibility to Soil Liquefaction Using the Standard Penetration Test (SPT)—A Case Study from the City of Portoviejo, Coastal Ecuador
Round 1
Reviewer 1 Report
I have attached my detailed comments in the pdf. Overall the paper has merit but there is a large degree of repetition in the text which leads to a paper which is difficult to follow. Quantity does not equal rigour I am afraid. I have tried to identify areas where being more focussed in the text would benefit.
There is also an alternating use of both comma and full stop to denote decimal places in both the text and the figures. I would assume the journal would prefer this to be all decimal points denoted by a full stop. In addition, the term perforation is interchangeably used with borehole that makes figures and text difficult to follow. The sheer volume of referencing in certain sections does cloud the relative importance of the works cited.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 1 Comments
First of all, we would like to thank you the expert reviewer for your valuable and constructive comments, which have substantially improved the manuscript in order to become more structured and readable. The changes we gave realized are highlighted in the text of the revised / edited version of the document. A point-by-point explanation of the response to your given comments follows below.
Point 1:
Unclear, defining Fs here may help
Response 1:
In the manuscript, the Fs for the city of Portoviejo was defined as 1,169, where values higher than this did not present liquefaction, as shown in Table 5 Liquefaction Probability proposed by Chen and Juang 2000.
Manuscript:
From these data, a liquefaction hazard map has been realized for the city of Portoviejo, where an Fs of 1,169 was obtained. There it has been determined that strata between 8 and 12 m of depth are potentially liquefiable, allowing to indicate the degree of severity of the superficial evidence of liquefaction.
Point 2
The rapid population growth isn't in the soils... Also this sentence is way too long.
Response 2:
The idea of the paragraph was restructured
Manuscript:
Within areas with high levels of seismicity, where the recurrence of earthquakes includes intervals between 20 to 70 years, and where soils are susceptible to co-seismic ground deformations, it is absolutely necessary to perform continuous studies in order to understand which urban areas may be susceptible to liquefaction.
Point 3
Broken sentence
Response 3:
Good catch, now eliminated
Point 4
What to all these reference refer to? The full stop before the sentence means the application is unclear.
Response 4:
The point was removed, since the quotes are related to figure 1.
Point 5
Repeated paragraph. This is effectively duplication of the paragraph at the bottom of P1.
Response 5:
Sorry for that, rhe repeated paragraph was obviously removed
Point 6
Superscript
Response 6:
Subscripts were corrected
Point 7:
ref not defined
Response 7:
The reference was placed
Point 8:
Definition of PGA
Response 8:
The definition of the acronym PGA was placed in the manuscript.
Manuscript:
Peak ground acceleration (PGA)
Point 9:
This seems at odds to the aim of the paper in the abstract?
Response 9:
This paragraph was removed as it created confusion regarding the objective of the investigation.
Point 10:
Given this figure is in the literature review should this have a reference to go with it?
Response 10:
Yes, the reference was placed in the figure caption
Point 11:
unclear what you are referring to. Stratified beds?
Response 11:
This paragraph was restructured
Manuscript:
The urban area for the most part has soft soils, classified as silt, clay and intercalated strata of sand However, the geomorphological features in the hydrographic basin from north to south in the direction of the seismic subduction zone (NS), would certainly obtain an unfavorable condition for soil behavior (Figure 3).
Point 11:
I think this may read better as a table.
Response 11:
Se resumió la información en una tabla
Manuscript:
|
Sector (Epicentro) |
Fecha |
Magnitud (Mw) |
|
Bahía de Caráquez, |
3 de Mayo de 1896 |
7.1 |
|
Muisne |
1 de junio de 1907 |
7.4 |
|
Pedernales |
14 de Mayo de 1942 |
7.9 |
|
Bahía de Caraquez |
16 de Enero de 1956 |
7.4 |
|
Bahía de Caraquez |
4 de agosto de 1998 |
7.1 |
|
Pedernales |
16 de abril del 2016 |
7.8 |
Point 12:
formatting of Lf
Response 12:
The format of equation 1, 2 and 3 was modified
Manuscript:
Strike slip faults: Mw = 5.56 + 0.87*Log(Lf) (1)
Normal faults: Mw = 6.12 + 0.47*Log(Lf) (2)
Reverse faults: Mw = 4.11 + 1.88*Log(Lf) (3)
Point 13:
comma used as decimal point in this table
Response 13:
In the entire text, the comma (,) has been replaced by a period (.) for decimals.
Point 14:
This definition should be at the first occurrence.
Response 14:
The significance and or meaning has been defined when it is first time named.
Manuscript:
Point 15:
Format correctly
Response 15:
We changed the formula to the correct format
Manuscript:
PGAestimated = (10^(0,41*Me-Log10(Hf+0,032*10^(0,41*Me))-0,0034*Hf+1,3))/980
Point 16:
- a) and b) are not defined in the Figure 3
Response 16:
Points a and b were defined in figure 3 related to the local geological map of the city of Portoviejo (a), and location of the boreholes (b) Adapted and modified from Cando-Jácome et al.[51].
Manuscript:
See figure 3
Point 17:
Refer to Table 1
Response 17:
Because a new table was added, which was table 1 became table 2. Hereby, a reference was made in the text to table 2 when referring to the catalog with the 14 faults.
Manuscript:
The seismicity related to a geological fault, a catalog with 14 faults capable of deforming the ground surface and able to generate modest-to-strong earthquakes was compiled as listed in table
Point 18:
This is superfluous and is covered in the text before Table 1
Response 18:
The paragraph was deleted
Manuscript:
Point 19:
Define TPI
Response 19:
The abbreviation was defined
Manuscript:
Topographic Position Index (TPI)
Point 20:
What is the purpose of this reference? It reads currently like the work is from this paper? If it is just the method then add this to the 'methods' statement in the 2nd line of the paragraph
Response 20:
The observation was considered in the manuscript, since the method is mentioned in the methods and materials section.
Manuscript:
The thicknesses of the lithological units of the soil, as well as the seismic profiles of shear waves through the method of Nakamura [63] were analyzed with 23 available boreholes up to 30 meters deep, where values of Number of SPT blows, granulometry, water content are presented in soil, variation of soil saturation degree, liquid limit (LL) and plasticity limit of soil strata samples
Point 21:
The thicknesses of the lithological units of the soil, as well as the seismic profiles of shear waves through the method of Nakamura [63] were analyzed with 23 available boreholes up to 30 meters deep, where values of Number of SPT blows, granulometry, water content are presented in soil, variation of soil saturation degree, liquid limit (LL) and plasticity limit of soil strata samples
Response 21:
Zone zero, where the AB profile was built, is where the highest record of damage to homes and buildings occurred during the 2016 Pedernales seismic event.
Manuscript:
A geological profile (AB) with a NE-SW direction of 2.8 km in length has been performed for the "zero zone" of the city of Portoviejo (Fig. 3 and 4), being there recorded the highest number of damages to homes and buildings in the city of Portoviejo during the seismic event located in Pedernales in 2016 (Mw 7.8)
Point 21
Most of this entire paragraph is contained within Table 2. Minimise duplication were possible.
Response 21:
The mentioned duplication was removed
Point 21:
This doesn't really help the reader understand what you have done. Only all the available methodologies.
Response 21:
Citations that do not correspond to the methodology were eliminated.
Point 22:
This may all be useful, but currently I cannot see the relevance as you methodology is not clearly defined. What method did you follow?
Response 22:
The methodology used was by Chen and Juang (2000) and was subsequently added to the manuscript
Manuscript:
To determine the probability of liquefaction in the city of Portoviejo, the methodology proposed by Chen and Juang [38] was used, whose objective is to calculate the safety factor per stratum, considering it as the ratio between the cyclic resistance ratio (CRR ) and the cyclic stress ratio (CSR).
Point 23:
This doesn't really help the reader understand what you have done. Only all the available methodologies.
Response 23:
Information that is irrelevant has been removed.
Point 24:
I'm used to seeing this as rho and not gamma. Gamma being unit weight not density
Response 24:
ɤ was replaced by ρ
Point 25:
It is not clear what the 1st approach is to the problem
Response 25:
This paragraph was deleted as it confuses the objective of the investigation
Point 26:
At what depth are these samples from?
Response 26:
The analyzed samples were taken at a depth of 10 meters.
Point 27:
Not sure why you have all the boreholes listed here as there no way to cross reference them
Response 27:
The number of perforations was deleted since, according to your correct comment, it is not possible (and not really necessary) to identify them.
Point 28:
Did you do calculations below 20m?
Response 28:
No, the liquefaction analysis is calculated only down to 20 m of depth.
Point 29:
This section is actually the calculation of the Factor of Safety
Response 29:
Indeed, the section to which it refers is the calculation of the safety factor, therefore the subtitle was changed.
Point 30:
Check parameter subscripts eg sigma_v
Response 30:
The subscripts were changed according to your recommendation.
Point 30:
If the LPI is an integral with depth, how is it represented at defined depths in Fig 7c
Response 30:
Figure 6c represents the LPI for each borehole per meter, since it is easier to determine which are the strata where liquefaction has the greatest influence.
Point 31:
Many of the scales here could be better represented rather than simply listing scale.
Response 31:
The LPI ranges were placed using tables for both those proposed by Iwasaki et al. (1982), as we did also with Sonmez (2003)
Point 32:
Don't recite the scales of others.
Response 32:
These scales were erased
Point 33:
English please
Response 33:
Sorry for that, paragraph was translated
Point 34:
Why all caps?
Response 34:
Unnecessary, therefore corrected
Point 35:
Nothing is discernible from this figure from the 10 analyses. What are you trying to show?
Response 35:
Figure 10 was replaced by one that illustrates the average of all the 10 seismic records that are most similar to the one that occurred on April 16, 2016. Hereby, the graph of the 10 records was eliminated by the average of them in order to compare them with that of the NEC for soil type D resulting from the analysis.
Point 35:
What was your control in this case? Why use these 10, why 10?
Response 35:
The selection of the records was made according to the characteristics that they present when compared with the earthquake that occurred on April 16, 2016, considering magnitude, Vs 30, Rrup. Of these 10 earthquakes, an average was realized and it was compared with that of the NEC for type D soils.
Point 36:
specific weight?
Response 36:
Specific weight was replaced by weight unit
Point 37:
Repetition
Response 37:
The paragraph was deleted
Point 38:
axes labels?, too many plots on same figure...
Response 38:
They were reduced by averaging them.
Point 39:
Isn't this a conclusion
Response 39:
Indeed, this paragraph was placed in the section of our conclusions
Point 39:
Not clear how this has been related to the Jama earthquake.
Response 39:
The wording has been improved in order to not to confuse the reader.
Again, we are very thankful for your constructive comments, on behalf of all authors
Reviewer 2 Report
The paper entitled "Susceptibility to Soil Liquefaction, Through Standard Penetration Test (SPT) - A Case Study from the City of Portoviejo, Coastal Ecuador" is an interesting research on liquefaction by standard penetration tests.
- The paper can be published after some corrections.
- Page 1, Line 38; Page 2, Line 57, 82: “Chunga et al., 2019” is absent in the References.
- Page 1, Line 42, 44; Page 2, Line 64, 82, Page 9, Line 339: In the References there are two “Chunga et al., 2018”. Which one are you referring to?
- Page 1, Line 44: “Ye et al., 2016” is repeated twice.
- Page 2, Line 52: “Bahadori et al., 2016” probably is “Bahadori et al., 2017” (References).
- Page 2: The text from Line 53 to Line 58 and from Line 58 to Line 66 seems to have already been reported above.
- Introduction: Insert more details about liquefaction phenomena. For example considering the following paper:
-- Cavallaro A., Capilleri P. and Grasso S., (2018): "Site Characterization by in Situ and Laboratory Tests for Liquefaction Potential Evaluation during Emilia Romagna Earthquake"; Geosciences, Special Issue: "Site-Specific Seismic Hazard Analysis: New Perspectives, Open Issues and Challenges", Geosciences 2018, 8(7), 242, pp. 1 - 15. (ISSN: 2076-3263) DOI:10.3390/geosciences8070242.
-- Idriss, I.M.; Boulanger, R.W. "Semi-empirical Procedures for Evaluating Liquefaction Potential during Earthquakes"; In Proceedings of the 11th IC SDEE/3rd ICEGE Proceedings, Berkeley, CA, USA, 7 - 9 January 2004; Volume 1, pp. 32 - 56.
-- Idriss, I.M. "An Update to the Seed-Idriss Simplified Procedure for Evaluating Liquefaction Potential"; In Proceedings of the TRB Workshop on New Approaches to Liquefaction, Washington, DC, USA, 10 January 1999.
- Page 5, Table 1: “Leonard (2010)” is absent in the References.
- Page 8: The term “shear velocity” is to prefer to “shear rate” or “cutting speed”.
- References to Table 1 and Table 2 appear to be absent in the text.
- Page 9, Line 311: Check grammar and synopsis.
- Page 11, Line 388: The Liquefaction Probability is defined with the symbol LP. In Table 4 the Liquefaction Probability is defined with the symbol PL. In Table 3 Plasticity Limit is defined with the symbol PL. Establish a definitive symbol to avoid confusion.
- Page 11, Line 389: The Liquefaction Probability value equal to 0.914 and later which table do they refer to?
- Page 12, Line 416: In equation (1) the numbering restarts instead some equations have already been introduced previously.
- Page 12, Line 417 - 421. Check grammar and synopsis. The explanation of the factors is not very clear.
- Page 13, Line 466: “Juang et al.” probably is “Juang et al. 2000”.
- Page 13, Line 469: “Chen, 2000” probably is “Chen and Juang, 2000”.
- Page 15, Line 498 - 505: The text is not in English.
- Page 17, Table 6: Explain the terms shown in the table. Insert a caption as in Table 3.
- References: “Chlieh et al. 2014” are “Nocquet et al., 2014” are absent in the main text.
- While the initial part dealing with Liquefaction is reported in an exhaustive manner, the final part dealing with Site Response Analysis is reported too hastily.
Comments for author File: Comments.pdf
Author Response
Response to Reviewer 2 Comments
First of all, we would like to thank you the expert reviewer for your valuable and constructive comments, which have substantially improved the manuscript in order to become more structured and readable. The changes we gave realized are highlighted in the text of the revised / edited version of the document. A point-by-point explanation of the response to your given comments follows below.
Point 1:
Page 1, Line 38; Page 2, Line 57, 82: “Chunga et al., 2019” is absent in the References.
Response 1:
The corresponding reference was placed
Point 2
Page 1, Line 42, 44; Page 2, Line 64, 82, Page 9, Line 339: In the References there are two “Chunga et al., 2018”. Which one are you referring to?
Response 2:
The reference was duplicated, and, subsequently one of them was deleted
Point 3:
Page 1, Line 44: “Ye et al., 2016” is repeated twice.
Response 3:
The reference was duplicated, and, subsequently one of them was deleted
Point 4:
Page 2, Line 52: “Bahadori et al., 2016” probably is “Bahadori et al., 2017” (References).
Response 4:
Indeed, the reference is “Bahadori et al., 2017” and it was corrected
Point 5:
The text from Line 53 to Line 58 and from Line 58 to Line 66 seems to have already
been reported above.
Response 5:
Repeated lines which we proceeded to erase
Point 6:
Introduction: Insert more details about liquefaction phenomena. For example considering the
following paper:
-- Cavallaro A., Capilleri P. and Grasso S., (2018): "Site Characterization by in Situ and
Laboratory Tests for Liquefaction Potential Evaluation during Emilia Romagna Earthquake";
Geosciences, Special Issue: "Site-Specific Seismic Hazard Analysis: New Perspectives, Open
Issues and Challenges", Geosciences 2018, 8(7), 242, pp. 1 - 15. (ISSN: 2076-3263)
DOI:10.3390/geosciences8070242.
-- Idriss, I.M. "An Update to the Seed-Idriss Simplified Procedure for Evaluating Liquefaction Potential"; In Proceedings of the TRB Workshop on New Approaches to Liquefaction, Washington, DC, USA, 10 January 1999.
Response 6:
Great point, suggestion was considered, as it added more details about the liquefaction process based by the suggested authors
Point 7:
- Page 5, Table 1: “Leonard (2010)” is absent in the References.
Response 7:
Reference was added:
Leonard, M. Earthquake fault scaling: Self consistent relating of rupture length width, average displacement, and moment release. Bull. Seismol. Soc. Am. 2010, 100, 1971–1988.
Point 8:
Page 8: The term “shear velocity” is to prefer to “shear rate” or “cutting speed”.
Response 8:
Shear rate was placed
Point 9:
References to Table 1 and Table 2 appear to be absent in the text.
Response 9:
Table 1 and 2 are (now) mentioned in the text
Point 10:
- Page 9, Line 311: Check grammar and synopsis.
Response 10:
The idea was restructured to make clear what we would like to manifest
Point 11:
Page 11, Line 388: The Liquefaction Probability is defined with the symbol LP. In Table 4 the Liquefaction Probability is defined with the symbol PL. In Table 3 Plasticity Limit is defined with the symbol PL. Establish a definitive symbol to avoid confusion.
Response 11:
It is defined in the text as PL for probability of liquefaction, LP for plastic limit
Point 12:
Page 11, Line 389: The Liquefaction Probability value equal to 0.914 and later which table do they refer to?
Response 12:
Table 6 indicates a mean value of PL equal to 0.993, which corresponds to class 5 being identified as high probability. There was an error regarding the value indicated in the first review.
Point 13:
Page 12, Line 416: In equation (1) the numbering restarts instead some equations have already been introduced previously.
Response 13:
The indicated was corrected in the text
Point 14:
Page 12, Line 417 - 421. Check grammar and synopsis. The explanation of the factors is not very clear.
Response 14:
The writing and the synopsis was severely improved
Point 15:
- Page 13, Line 466: “Juang et al.” probably is “Juang et al. 2000”.
Response 15:
Indeed, the reference corresponds to “Juang et al. 2000”.
Point 16:
Page 13, Line 469: “Chen, 2000” probably is “Chen and Juang, 2000”.
Response 16:
Indeed, the reference corresponds to “Chen and Juang, 2000”.
Point 17:
Page 15, Line 498 - 505: The text is not in English.
Response 17:
Our mistake. The paragraph was placed in English
Point 18:
Page 17, Table 6: Explain the terms shown in the table. Insert a caption as in Table 3.
Response 18:
The terms were described at the end of the table
Point 19:
References: “Chlieh et al. 2014” are “Nocquet et al., 2014” are absent in the main text.
Response 19:
Since the references were not in the text, they have been removed. Sorry for that
Point 20:
While the initial part dealing with Liquefaction is reported in an exhaustive manner, the final part dealing with Site Response Analysis is reported too hastily.
Response 20:
Based on your comment, an average of the 10 earthquakes with the greatest similarity to the one that occurred on April 16, 2016 in Pedernales was made, the same one that was compared with that of NEC-11 for soil type D that occurs in the city of Portoviejo.
Again, we are very thankful for your constructive comments, on behalf of all authors
Reviewer 3 Report
The use of English (technical terms) language is not correct and it's absolutely below publication standards. The paper must be completely rewritten before resubmission.
Author Response
N.A.
