## 1 Introduction  
Studies on the static and dynamic behavior of cable-stayed bridges reveal that they are quite complex systems in which the experimental control of the structure compliance with the design schemes is crucial not only for the final proof test, that is necessary before the opening to traffic, but also during the bridge construction. For example, the deck launching is usually studied and controlled through staged analyses that are able to account for the progressive loading of stays, and the experimental verification of such forces may be crucial to obtain the final desired deck longitudinal profile. At the same time, the final proof test of cable-stayed bridges should not be limited to the control of the deck deformability, and a sufficient number of tests should be planned to check the overall static and dynamic behavior of the complex structural system. Several works in the literature focus on proof testing of cable-stayed bridges through dynamic and static tests. For example, [PERSON] et al. [1] presented the experimental response of two newly built cable-stayed bridges in Mexico that were subjected to static and dynamic loads, addressing the use of optical fiber sensors to perform the bridge monitoring during the tests. Also, [PERSON] et al. [2] showed static, ambient, and dynamic field test observations of the long span Nissibi cable-stayed bridge in Turkey, while [PERSON] et al. [3] discussed the static and dynamic tests that were performed on the Suifenhe cable-stayed bridge (China) after 12 years from its opening to traffic, with the aim of evaluating its health status. Other works only focus on results of static proof load tests before the bridge opening to traffic, such as for the Redzinski bridge in Wroclaw [4] and the Kao-Ping-Hsi bridge in Taiwan [5]. On the contrary, some works only deal with dynamic tests that were performed on the whole structure, such as for the Alamillo bridge in Sevilla [6], the Indiana bridge in Florence [7], the Vasco da Gama bridge in Portugal [8], and the Colquitz river bridge in Canada [9]. Furthermore, some works are also available in the literature dealing with the behavior of single components of bridges, such as those investigating the behavior of stay cables under severe weather [10] or temperature conditions [11], or those studying their tension forces [12] adopting dynamic tests. Concerning the usefulness of tests, many authors adopted in situ experimental campaigns to support the updating procedures of the investigated bridge numerical model; some examples in this sense are the works on the Yong river bridge [13], the Ting Kau bridge [14], and the Chonggin bridge [15] in China, the Porto Marghera bridge in Italy [16], and the famous Stonecutters bridge in Hong Kong [17]. Moreover, in the work of [PERSON] et al. [18] a new method for bridge damage detection that is based on a combined experimental and numerical procedure is proposed. Very recent works are also available in the literature dealing with innovative and unconventional methods to test cable-stayed bridges (and also bridges in general). For example, [PERSON] et al. [19] and [PERSON] et al. [20] proposed new vision-based procedures to perform measurement displacements through high-resolution cameras, testing their procedure on real case studies, such as the Cheonsa bridge in South Korea, and the Su Tong Yangtze river bridge in China. Furthermore, [PERSON], and [PERSON] [21] proposed an interferometric radar that was able to investigate the dynamic behavior of bridges and they tested their methodology on the new Arno river bridge in Italy. Finally, some interesting works deal with the static and dynamic monitoring of important cable-stayed bridges all around the world, such as the Millau viaduct in France [22], the Basarab bridge in Romania [23], and the Jindo bridge in South Korea [24].