Model Uncertainty for Displacement Prediction for Laterally Loaded Piles on Granular Fill

Round 1

Reviewer 1 Report

In order to evaluate the model uncertainty, this paper compares outputs of large-scale tests with predicted displacement from well-known laterally-loaded-pile formulations (p-y method proposed by the API and the horizontal reaction modulus) based mainly on SPT test.

In my opinion both the introduction and the conclusions are poor. The introduction does not provide sufficient background while the conclusions need to be improved and expanded.

Lines 12-14: abstract?

Lines 17 and 91: "comperes": compares?

Line 39: "The deposit thickness was about 20 meters of thickness ..."

Lines 56-57: unclear

Line 80: "the testes piles" ?

Line 85: "incl ude"

Lines: 145-147: unclear

Author Response

Responses to Reviewer 1

In order to evaluate the model uncertainty, this paper compares outputs of large-scale tests with predicted displacement from well-known laterally-loaded-pile formulations (p-y method proposed by the API and the horizontal reaction modulus) based mainly on SPT test.

In my opinion both the introduction and the conclusions are poor. The introduction does not provide sufficient background while the conclusions need to be improved and expanded.

Both are rewritten in order to make the paper`s point clearer.

Lines 12-14: abstract? Corrected

Lines 17 and 91: "comperes": compares? Corrected

Line 39: "The deposit thickness was about 20 meters of thickness ..." Corrected

Lines 56-57: unclear Rewritten

Line 80: "the testes piles" ? Corrected

Line 85: "incl ude" Corrected

Lines: 145-147: unclear Rewritten

Author Response File: Author Response.docx

Reviewer 2 Report

The Reviewer recommendation is to reject the paper in the present form. The Authors must improve the following aspects before resubmitting their paper:

1) Introduction. The Authors are encouraged to improve the literature review about this topic. The Reviewer can suggest the following references:

Handbooks:

a) Poulos, H.G.; Davis, E.H. Pile Foundation Analysis and Design; Wiley & Sons: New York, NY, USA, 1980.

b) Reese, L.C.; Van Impe, W.F. Single Piles and Pile Groups under Lateral Loading; AA Balkema: Rotterdam, The Netherlands, 2001.

Available analysis methods/codes:

a) Xu, L.Y.; Cai, F.; Wang, G.X.; Chen, G.X.; Li, Y.Y. Nonlinear analysis of single reinforced concrete piles subjected to lateral loading. KSCE J. Civ. Eng. 2017, 1–12.

b) Khari, M.; Kassim, K.A.; Adnan, A. Development of Curves of Laterally Loaded Piles in Cohesionless Soil. Sci. World J. 2014, 2014, 917174.

c) Mardfekri, M.; Gardoni, P.; Roesset, J.M. Modeling laterally loaded single piles accounting for nonlinear soil-pile interactions. J. Eng. 2013, 2013, 243179.

d) Stacul, S., Squeglia, N., & Morelli, F. (2017). Laterally Loaded Single Pile Response Considering the Influence of Suction and Non-Linear Behaviour of Reinforced Concrete Sections. Applied Sciences, 7(12), 1310.

e) Yang, Z.; Jeremić, B. Numerical analysis of pile behaviour under lateral loads in layered elastic–plastic soils. Int. J. Numer. Anal. Methods Geomech. 2002, 26, 1385–1406.

f) Budhu, M.; Davies, T.G. Nonlinear analysis of laterality loaded piles in cohesionless soils. Can. Geotech. J. 1987, 24, 289–296.

g) Ashour, M.; Norris, G.; Pilling, P. Lateral Loading of a Pile in Layered Soil Using the Strain Wedge Model. J. Geotech. Geoenviron. Eng. 1998, 124, 303–315.

Lateral Load tests case histories:

A free database of lateral load tests can be found at the following website developed by the Deep Foundation Institute:

http://www.findapile.com/

a) Brown, D.; Morrison, C.; Reese, L. Lateral load behavior of pile group in sand. J. Geotech. Eng. 1988, 114, 1261–1276.

b) Cox, W.R.; Reese, L.C.; Grubbs, B.R. Field testing of laterally loaded piles in sand. In Proceedings of the Offshore Technology Conference, Houston, TX, USA, 6–8 May 1974.

2) The Authors should remove references 6 and 7, as they are not of great  relevance for the topic addressed by the Authors.

3) Geotechnical conditions at the test site are too briefly described. As the lateral response of a single pile is mainly affected by the soil conditions and properties at few diameters depth (5-7D, in this case corresponding to 4 meters), the Authors should focused on the shallower soil layers characterization. Moreover, also the water table depth (and season) both during the installation of the pile and the execution of the lateral load test must be specified.

4) Also the lateral load test procedure and the API and Kh model are too briefly described.

Author Response

Responses to Reviewer 2

The Reviewer recommendation is to reject the paper in the present form. The Authors must improve the following aspects before resubmitting their paper:

1) Introduction. The Authors are encouraged to improve the literature review about this topic. The Reviewer can suggest the following references:

Handbooks:

The introduction and conclusions have been modified.

Available analysis methods/codes:

Lateral Load tests case histories:

A free database of lateral load tests can be found at the following website developed by the Deep Foundation Institute:

http://www.findapile.com /

Regarding the references, authors are aware that this topic has been treated in many handbooks and papers. they do not pretend to present a complete review of all available approaches. However, codes and standards currently propose a basic version of these formulations, and these are frequently used by engineer in most practical cases. The paper aim is to assess the reliability of these well-known formulations, in order to provide a critical view of them.

Authors have added the free database to their paper as it is considered that the cases described can be included in that database.  The database has only two cases of metallic piles driven in granular soil. Both cases are for large diameter piles. Therefore the case described in this paper can be a relevant contribution to that database.

2) The Authors should remove references 6 and 7, as they are not of great relevance for the topic addressed by the Authors.

We agree and remove those references.

3) Geotechnical conditions at the test site are too briefly described. As the lateral response of a single pile is mainly affected by the soil conditions and properties at few diameters depth (5-7D, in this case corresponding to 4 meters), the Authors should focused on the shallower soil layers characterization. Moreover, also the water table depth (and season) both during the installation of the pile and the execution of the lateral load test must be specified.

A paragraph describing water condition is added, even though its position is already included in the table 2 and 3. Those tables show the layers above and below water level.

Soil conditions are described in figure 2 and 3, given values of N_SPT and CPT point resistance. The soil investigation outputs are represented against vertical stress instead of depth, but an easy to obtain relation exits between them.

4) Also the lateral load test procedure and the API and Kh model are too briefly described.

The paper includes a brief description of the used methods. Full description of them can be found on the included references. The new reference from the Deep Foundation Institute also includes a full development of this formulation.

Author Response File: Author Response.docx

Reviewer 3 Report

The paper describes a case study of lateral pile load testing interesting to design. The investigation results are plausible and the paper is well written.The paper is best suited for presentation in one of the numerous  specialized conferences. Alternatively, it may be published as a Technical Note in the journal.

Author Response

Responses to Reviewer 3

The paper describes a case study of lateral pile load testing interesting to design. The investigation results are plausible and the paper is well written. The paper is best suited for presentation in one of the numerous specialized conferences. Alternatively, it may be published as a Technical Note in the journal.

Authors thank the reviser and appreciate their assessment. Authors still think that the paper has high interest for engineers and researchers  since it is a very recent work where monitoring techniques are more accurate that the ones used so far, and soil conditions are well-knows, so that model uncertainty is really the only aspect that can be into discussion.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

In this paper the Authors attempted to investigate about the uncertainty associated with commonly used methods for the assessment of the displacements of laterally loaded piles.This study compared predictions using well-known formulations for laterally-loaded piles with the results of large-scale tests. However, as a matter of fact it is not possible to provide a proper insight about p-y and horizontal reaction modulus models uncertainty by comparing the results obtained with these two approaches and those obtained in a very limited number of large-scale lateral load tests (tested in the same site). The Authors did not improve enough their paper, thus a lot of work is needed if the aim is to study the uncertainty of methods commonly used in practice.