# A Study on the Impact of Low-Frequency Random Loading and Unloading on Silo Structures
## 1 Introduction  
With the rapid development of the national economy, various production enterprises have increasingly high demands for storage and operation. Silos are widely used in industrial and agricultural industries due to their small footprint, ease of mechanization, automated operation, and low storage costs. Among them, large-diameter reinforced concrete silos are often used in the cement industry because of their high strength, durability, good construction performance, low cost, and strong plasticity. Under normal use conditions, concrete mainly bears the compressive force, while the steel bars mainly bear the tensile force. In the limit state of the silo, when the concrete cracks and fails, the steel bars will start to bear more tensile force to maintain the stability of the overall structure. Therefore, in the design process, it is common to effectively improve the silo's tensile strength, delay cracking failure, and enhance the overall performance of the structure by increasing the amount of reinforcement. However, due to the relatively low tensile strength of concrete, cracking occurs when it is subjected to large tensile forces. Therefore, crack resistance calculations must be performed during silo design, and according to standard anti-cracking designs, the quantity and arrangement of the reinforcement should be adjusted to ensure that the crack width does not exceed 0.2 mm. However, in actual use, some silos develop horizontal and vertical cracks in the silo walls under material pressure, with crack widths exceeding the designed allowable value. Additionally, problems such as concrete peeling, exposed reinforcements, and reinforcement falling off may occur on the silo walls. Facing this issue, [PERSON] [1] combined practical engineering cases to investigate the causes of the widespread problem of reticulated cracks in the walls of concrete circularsilos and proposed the corresponding reinforcement methods. Through empirical research, the effectiveness of the proposed design and construction improvement suggestions was verified, providing effective solutions to problems encountered in practical engineering. [PERSON] [2] analyzed the causes of sliding formwork cracks in a coal preparation plant silo based on actual engineering cases and proposed improvements for sliding formwork construction techniques, which have important application value for practical engineering projects. [PERSON] [3] comprehensively analyzed the common quality problems in the sliding formwork construction of silos and proposed targeted solutions. Based on their paper, construction workers can understand the problems that may be encountered in sliding formwork construction of silos more clearly and take preventive and corrective measures based on the proposed countermeasures, thereby significantly improving the construction quality and efficiency. This research has practical guiding significance. [PERSON] et al. [4] evaluated the performance of circular reinforced concrete silos based on different criteria and concluded that inadequate crack control can lead to a rapid decrease in strength, potentially causing premature structural failure. They also found that different construction methods have a certain impact on performance. [PERSON] [5] introduced the importance of thermal loads on silos under high-temperature conditions and their impact on the reinforcement measures that are required for the design structure. She summarized the background information for determining thermal loads and conducted research on silo wall damage caused by temperature using numerical analysis. [PERSON] [6] used ANSYS 7.0 software to thoroughly explore the specific impact of temperature on the pressure distribution of grain silos, carefully considering the combined effects of temperature changes on the plastic and elastoplastic behavior of the silo structure. The research showed that the temperature effect mainly has a significant impact on the elastic region.