Evaluation of the Szapáry Long-Span Box Girder Bridge Using Static and Dynamic Load Tests

Round 1

Reviewer 1 Report

This study investigated the static and dynamic mechanical behavior of a long-span box girder bridge based on on-site loading tests. The measurements of girder deflection, stress, and dynamic mode shapes are very useful and can provide a theoretical basis to verify the bridge design methods of this type of bridge. The manuscript is interesting and well-organized. Some numerical results should be rechecked to verify the accuracy.  Please consider the following comments:

(1) L326, the limit of deflection is related to the bridge type and girder materials. Please check if L/400 is suitable for the steel girder bridge in the present study.

(2)  Fig. 14, the deflection line for a driving speed of30 km/h is abnormal, since the vibration is too severe. The author should check the computed value.

(3) Fig. 15, the DAF estimated by MIDAS is always less than 1. The is abnormal and needs check.

 

(4) Go through the manuscript to correct typos, such as the y-label in Figure 11.

Seems good.

Author Response

Our replies to reviewers are submitted as word files:

Response to Reviewer 1 and Response to Reviewer 2

Author Response File: Author Response.docx

Reviewer 2 Report

The present paper summarizes the results of full-scale tests performed before the opening of a motorway bridge in Hungary. The investigated bridge includes two independent box-girder structures, each supporting one roadway and consisting of 7 spans with lengths of 96 m + 120 m + 148 m +120 m + 96 m + 96 m + 80 m. The proof tests of the bridge included both static and dynamic tests and extensive discussion on the results of static tests is reported in the paper. As usual, the experimental assessment was complemented by the development of a FE model of the structure and by the comparison between numerical and experimental results.

Although the paper does not present any novelty in terms of both experimental and methodological aspects (proof load tests of bridges are mandatory in many countries), the manuscript summarizes the results of an interesting case study, so that publication is suggested. Moreover, the manuscript is quite well arranged and written. On the other hand, before publication the following aspects should be amended:

(1) Often the term "monitoring" is used instead of "testing" !! Recalling that monitoring involves the repeated (or continuous) collection of experimental measurements, it is mandatory to check the entire manuscript in order to use the appropriate term: to better exemplify the reviewer's point, it is suggested to substitute the term "monitoring" in the title of section 2 and of sub-sections 2.1, 3.1, 3.2;

(2) Various part of the manuscript refer to ambient vibration tests but no results of those tests are presented in the paper. Furthermore, I suggest to identify the bridge modal parameters (i.e., natural frequencies, mode shapes and damping ratios) by using techniques that are more robust and refined than simple FFT;

(3) For the merit of readers, more details (and figures) on the FE model should be added;

(4) Figures 7 and 8 are spread in 2 pages: please amend;

(5) Please note that eq. (2) precedes eq. (1): please amend.

Minor editing of English language suggested

Author Response

Our replies to reviewer suggestions are uploaded in two word files Response Reviewer 1 and Response Reviewer 2

Author Response File: Author Response.docx