The Role of Soil Structure Interaction on the Seismic Resilience of Isolated Structures

Round 1

Reviewer 1 Report

This paper presents a parametric investigation of the role of Soil-Structure Interaction (SSI) on the seismic resilience of an isolated building.

The main novelty of this paper is the focus on seismic resilience whilst past papers addressed the problem of the SSI on the structural behaviour (internal forces, displacements, modal properties,...).

It should be emphasized that results are limited to the analysed 1 building and cannot be extrapolated for general considerations.

English language should be checked since there are some mistakes in the introduction and in the subject/verb agreement.

Specific comments :

1) The Author selected 10 earthquakes in order to meet the prescriptions of the seismic code of having a spectrum-compatible set of accelerograms. On the other hand, the following analyses deal with each signal independently. It would be more appropriate to draw conclusions and comments from the average behaviour as it is supposed by the building code. The prescribed spectrum is related to a specific limit state but due to the great variance of the selected inputs, each one triggers a different limit state. It is not clear why the Author did not perform an incremental dynamic analysis or just select earthquakes with increasing magnitude. Therefore either Section 3.3 is useless or a discussion of the average result as a function of the type of soil is missing in the result section.

2) Tables 6 to 9 are difficult to read. They just show raw data and another visualization method should be sought. 

3) In line 113, the Author mentioned that the slab has been modelled via PIMY. It is not clear why the foundation has been modelled through a constitutive behaviour usually adopted for the soil and anyway, why Table 3 reports only the elastic properties. I think that several parameters are missing in order to characterize the nonlinear behaviour of the soil and foundation.

4) Soil S o surrounding soil is not defined properly. What are his dimensions? What is the difference with Soil F?

5) In line 93, the Author presented the case studies by saying that the soil velocity will increase every 10m/s (80 analysis for each configuration). This is not clear and I cannot see it in the following results.

6) The description of the isolators is not clear (maybe an image would help). Why they are 2 per column and how they are connected?

7) Cross-section dimensions and masses are not reported. Therefore, the structure cannot be replicated.

Minor:

I) BI has not been defined at line 48

ii) why the acronym SSI in the title? I do not see the necessity

iii) line 57, capital letter

iv) line 150, with "increasing..." but the order is decrescent

v) Recovery Time, does it have units?

vi) the Last figure is very large and without the caption

 

Author Response

Many thanks for your time and effort. Your observations/requests were considered and helped to improve the paper.

Please see the attached document.

Author Response File: Author Response.pdf

Reviewer 2 Report

I have reviewed the paper « The role of soil structure interaction (SSI) on the seismic resilience of isolated structures » by Davide Forcellini.  

It is an interesting manuscript dealing with the effects of SSI on the seismic behavior of isolated structures. The present reviewer thinks that the manuscript links with the aims and scope of the journal Applied Sciences. 

A list of some suggested corrections/questions follows in order to improve the manuscript : 

1) The bibliography needs to be strengthened with more articles in the first paragraph. There is also references who investigate the local site conditions of the soil and their effects in the isolated structures. I.-K. Fontara, M. Titirla, F. Wuttke, A. Athanatopoulou, G. Manolis, A. Sextos “Multiple support excitation of a bridge based on a BEM analysis of the subsoil-structure interaction phenomenon” COMPDYN 2015, Greece; 05/2015. 

2) In the line 106, what means seismic masses?  

3) In the line 111, the authors mentioned that the foundation is 35mx23mx0.5m, also, they referred the figure 2. But in the figure 2 the foundation is 26mx14mx0.5m. Please modify. 4)The authors need to increase the numbers of the models in order to have safer results. 

5) Model B3, the typology is with two-spring model? What about the vertical stiffness and the rotation in the 3 directions?  

6)Where exactly is the soil S and where the soil F? Please explain and modify the Figure 1 with more details.  

7) Why the authors checked only the longitudinal direction? (line 174) The author needs to investigate also the effects in bi-directional accelerations.  

8) The results are well presented but the study needs to improve with more models. 

9) Double check of the manuscript.

Author Response

Many thanks for your time and effort. Your observations/requests were considered and helped to improve the paper.

Please see the attached document.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The manucript can be published in present form.