Nonlinear Stiffness of Semi-Fixed Dowel Joints in Semi-Integral Bridges

Round 1

Reviewer 1 Report

Reviewer (Comments to the Author): This paper presents an interesting study of the non-linear stiffness of semi-fixed dowel joints. The joints of the Chinese Jingpu Bridge, which has been retrofitted, are tested as prototypes. Furthermore, new calculation formulas for the stiffness of this type of joint are presented.

 

The paper is well written, procedures and results are clearly exposed, and the discussion is satisfactory. This is a starting point for other future studies that can further enrich the knowledge on these types of devices.

 

In the opinion of this reviewer, the article is worthy of publication.

 

General comment: The English language is fine, just a little spell-checking is required. Also, the manuscript does not respect the template. This aspect must be revised.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper examined the effectiveness in terms of stiffness of a dowel-type expansion joint for bridges specimens. Four specimens of this type of joint were constructed and tested under lateral load in the laboratory, and the experimental results were used to form the basis for equations to predict flexural stiffness. In this reviewer’s opinion, the introduction provides a brief but adequate background and literature review. The specimen details were justified, based on the existing bridge used as a prototype, and the test setup was reasonable. The quality of the figures is good.

The paper could be improved in the following ways:

1. The failure mode for the dowel joints was not examined. Why? An explanation would be appropriate in this reviewer’s opinion because the mode of failure could explain the nonlinear stiffness behavior and because the mode of failure provides info on the joint’s ductility and over-strength, which would be vital for bridges in seismic regions.

 

2. The conclusions would be improved by including a succinct summary of what was done in the study, before listing the main findings.

 

3. The manuscript is difficult to read throughout. Therefore, I recommend that the manuscript revised for spelling, grammar, and clarity. I started keeping track of editorial comments, but stopped after it was apparent that the errors were throughout the entire paper. Here are some examples. 
   • In the abstract “type joint” probably should be written “type of joint”, and “relevant specifications formulation” should probably be written “for formulation of relevant specifications.”
   • Another example: the first line of the introduction should probably be rewritten to express something like most small and medium span bridges are simply-supported beam type structures, of something similar.
   • Another example: “integrated the superstructure and the abutments” is not correct grammatically.
   • Another example: “by tolerated 75 years of displacement” is not correct grammatically.

 

4. Editorial comments:
   • Consider enlarging Figures 1 and 2 and pointing out the location of the expansion joints in Figure 2 through labels, arrows, or other annotation.
   • It is unclear sometimes what quantities are being raised to a power. For example, the equations in the middle of page 11: is the term being raised to 2.31?
   • Missing equation number at top of page 12?
   • Red equals sign on this equation?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The paper investigates semi-fixed dowel joints. The paper is well written in general. few comments as follows: 

1- the literature can be improved, covering more studies. Here is an example: https://doi.org/10.1016/j.engstruct.2020.111213

2- Would you mind double-checking the punctuations? 

3- Would you mind addressing the innovation of the paper at the end of the introduction? 

4- Would you mind presenting the concrete material properties?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have adequately addressed the comments from the previous review.