A Study on the Design of a New Three-Dimensional Seismic Isolation Bearing Based on an Improved Genetic Algorithm for Bridge Engineering

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, the authors propose a new approach to design three-dimensional seismic isolation bearings for bridge structures. The study aims to overcome the limitations of traditional passive seismic isolation devices, which frequently fail to perform effectively under varying seismic loads, by implementing a metaheuristic optimization algorithm. The authors propose a methodology for analyzing and optimizing isolation bearing design parameters by combining the optimization center gradient method with an improved genetic algorithm. The primary goals are to reduce acceleration transfer rate, material use, and improve bridge seismic performance. Experimental results seem to support the proposed design effectiveness by demonstrating improved seismic isolation when compared to traditional methods.

The article exhibits a well-organized structure and clear presentation. The writing is understandable, although it is apparent that the authors are not native English speakers. Overall, the results are effectively communicated, and the topic is both intriguing and promising. The proposed approach represents a valuable tool that can be widely applied in seismic isolation engineering.

2.      The literature review lacks depth, particularly in its discussion of optimization protocols applied to seismic protection. Specifically, it does not reference key review papers that thoroughly explore the use of optimization techniques in the seismic protection of structures. Some examples are reported in the following:

-        Marano, G. C. et al. (2022, September). Optimization as a tool for seismic protection of structures. In World Conference on Seismic Isolation (pp. 100-113). Cham: Springer International Publishing.

-        Zakian, P., & Kaveh, A. (2023). Seismic design optimization of engineering structures: a comprehensive review. Acta Mechanica, 234(4), 1305-1330.

3.      The graphs in the article are unclear and too small to be easily readable. In addition to maintaining the differentiation of the data by line types, the reviewer suggests using different colors to better distinguish the data series. It is also recommended to increase the size of the figures and enlarge the lettering on the graphs to improve clarity and readability.

4.      The authors state that 'Genetic algorithms are intelligent optimization algorithms known for their strong global search capabilities and high computational efficiency, making them particularly advantageous for solving unimodal optimization problems.' This statement is misleading. While genetic algorithms are more efficient than brute-force approaches, they are certainly less computationally efficient than gradient-based algorithms. The real advantage of using genetic algorithms lies not in their 'high computational efficiency,' but in their ability to handle objective functions that are discontinuous, non-differentiable, or complex, where traditional gradient-based methods would fail.

5.      The results presented in Section 4 demonstrate the effectiveness of the seismic isolation device in reducing the impact of ground accelerations on the structure by comparing isolated and non-isolated structures. While this confirms the absolute effectiveness of the device, it does not validate the proposed optimization method. To demonstrate the effectiveness of the optimization approach, the authors should have compared two isolated structures—one using the optimized device and the other using a conventional device. This comparison would more clearly show the advantages of the optimization method over standard approaches.

In conclusion, the paper is deemed interesting, and the reviewer recommends it for publication after the requested major revisions are addressed.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The reviewer suggest to proof read the paper because some of the sentences are overly complex or disjointed, which makes them harder to read. For example, in the abstract the sentence “However, for passive seismic isolation devices, due to their non-adjustable performance parameters, it is challenging to achieve a good seismic isolation effect for structures under random and variable seismic loads in the wide frequency range of 0 Hz to 20 Hz.” is way too complex and should be simplified to increase the readability of the manuscript. Moreover, throughout the paper, there are missing commas after introductory phrases, such as: "In response to the issues mentioned above" should be followed by a comma. "Firstly" and "Subsequently" in methods also need commas after them. These changes can enhance readability and ensure the paper flows more smoothly.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors of the manuscript presented an interesting study concerning the optimization of a three-dimensional seismic isolation bearing. As a quantitative function of the optimization process, minimizing the acceleration transfer rate was chosen. During the optimization process, AI (genetic algorithm) was used.

The analysis presented by the authors is valuable and interesting, and the results obtained are very promising. The use of AI-based methods in optimization algorithms is becoming a natural and obvious part of the design process, especially for bearings and isolation systems. I am glad that the authors have undertaken such a trending topic.

The article is clear and well-thought-out, and the conclusions drawn by the authors are correct. However, there are several elements in the paper that need to be improved before the manuscript can be published. The following issues require corrections or commentary:

General comments:

1.      The authors should cite more research works directly related to the application of artificial intelligence in building design. There are several studies addressing similar topics, especially in the last 2-3 years.

 

2.      In Section 3, the authors state that optimization will be conducted with regard to the vertical stiffness value K_V. What about the horizontal stiffness K_H? The horizontal component of seismic excitation plays a crucial role in the dynamic response of structures and could be very dangerous for tall objects as well as bridges. So, what is the relationship between the obtained vertical stiffness K_V and K_H? The authors' idea was to design three-dimensional isolation bearings, so information about their horizontal properties should also be presented. Currently, the presented information is incomplete.

 

3.      It must be clarified in the text whether the authors used uni- or multi-directional excitation during the validation experiment on the shaking table. Moreover, it should be explained whether the authors employed similarity scales during the experiment or not. If not, please clarify how the obtained results can be related to real-world structures. The results obtained for an 80kg object under real (unscaled) seismic excitation are far from the results expected for actual structures. Results obtained in this manner will not be applicable in the design process of real bearings.

 

Overall recommendation: Accept after Major Revisions

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The reviewer thanks the authors to address all the comments.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed all the reviewer’s comments. The responses are satisfactory and fully clarify the concerns raised in the review.

I'm impressed, and I congratulate the authors.

In the reviewer opinion the article can be published in its current form.