# Study on the Vibration Effects of Cyclic Blasting on Bridge Structures under Construction
## 1 Introduction  
Blasting is a widely employed technique in various engineering fields, including water conservancy, hydropower engineering, highway and railway construction, and mining. The vibrations generated by blasting during construction can impact the stability of bridge structures. Repeated exposure to these vibrations can lead to cumulative damage, which, if it exceeds a certain critical threshold, will inevitably result in structural compromise. Once the damage accumulates to a certain level, it poses a significant threat to the structural integrity and safe usage of the building [1; 2; 3]. Frequent disturbances exacerbate the extent of damage, significantly shortening the service life of the structure and potentially leading to direct structural failure. Currently, most studies on the effects of blasting on bridges focus solely on single blasting events, neglecting the impacts of cyclic blasting. Recently, numerous scholars have investigated the effects of blasting vibrations on nearby structures [4; 5]. [PERSON] et al. [6] analyzed the impact of blasting vibrations on nearby structures and early-stage concrete in the context of China's safety regulations on blasting vibrations. [PERSON] et al. [7; 8] assessed the safety impacts of blasting vibrations on reinforced concrete highway bridges, masonry buildings, and stone arch bridges by monitoring quarry blasting vibrations near urban centers in Turkey. [PERSON] and [PERSON] [9] investigated the response characteristics of structures subjected to blasting-induced ground motion. [PERSON] et al. [10; 11] examined the drift control design of reinforced concrete frame structures subjected to long-distance blasting conditions. The primary construction material of bridge structures is concrete. Numerous scholars have investigated the impact of blasting vibrations on the performance of newly poured concrete. [PERSON] et al. [12] indicated that repeated blasting loads during excavation accelerate the development of damage zones in the surrounding rock. Studies have shown that the macroscopic failure of engineering rock masses due to cyclic blasting is induced by repeated blasting disturbances. [PERSON] and [PERSON] [13] experimentally investigated the early properties of high-performance concrete. [PERSON] et al. [14] examined the early strengthdevelopment of outer concrete in well walls through both laboratory and field tests. They discovered that the early strength development of mass concrete is rapid, with the strength at 3 and 7 days reaching 70% and 90% of the final strength, respectively. [PERSON] and [PERSON] [15] investigated the dynamic responses of adjacent buildings to subway tunnel blasting within a complex urban environment. They employed the Hilbert-Huang Transform (HHT) model to analyze blast-induced vibrations, introducing the concept of effective vibration duration to enhance hazard prediction and management. [PERSON] and [PERSON] [16] examined the impact of tunnel blasting on temporary middle walls. Their study identified significant damage proximal to the blasting source, progressing through stages of crack formation and subsequent structural failure. They formulated a BTS-based function for designing and evaluating the safety of temporary support structures. [PERSON] and [PERSON] [17] devised a modified PPV prediction formula for tunnel blasting, yielding accurate results in multihole, multistage blasting scenarios at the Guanlinzi Tunnel. [PERSON] and [PERSON] [18] explored the effects of multihole blasting on rock damage and vibration attenuation. Their study revealed the significant influences of blast-hole arrangement, delay time, and decoupling charge on peak particle velocity (PPV) attenuation parameters, which were validated with field data. These findings offer crucial insights for optimizing blasting designs and enhancing blasting effectiveness.