# Study on the Influence of Moisture Content and Void Ratio on the Disintegration of Red Clay
###### Abstract  
Guilin is a famous karst area, and currently the view that the disintegration of red clay will cause soil cave collapse is increasingly recognized. In order to study the influence of the coupling effect of moisture content and void ratio on the disintegration of red clay, different moisture contents and void ratios of Guilin red clay were placed on a self-made disintegration apparatus to record the real-time disintegration amount and observe the disintegration phenomenon. Images of the structural characteristics of soil were obtained by a scanning electron microscope (SEM). Additionally, nuclear magnetic resonance (NMR) was applied to analyze the distribution of water in both natural and saturated states. The results show that the disintegration rate of red clay decreases as the initial moisture content increases, but increases with the increase of void ratio. Both moisture content and void ratio affect the structural characteristics of red clay. When the moisture content remains constant, the soil changes from a three-peak to a two-peak structure as the void ratio increases. The total area and secondary peak area of the T\({}_{2}\) spectrum increase, while the starting T\({}_{2}\) value of the main peak shifts to the right and the area decreases. Meanwhile, the starting T\({}_{2}\) value of the secondary peak shifts to the right and the area increases. When the void ratio remains constant, the starting T\({}_{2}\) value of the main peak gradually shifts to the left and the area decreases as the moisture content increases. However, the starting T\({}_{2}\) value of the secondary peak shifts to the right and the area decreases or first decreases and then increases. The disintegration rate does not exhibit a significant relationship with either pore volume or macropore volume. The combined water saturation shows a bilinear relationship with both the moisture content and void ratio, where it increases as the initial moisture content increases, but decreases as the void ratio increases, with a correlation coefficient of 0.9929. The disintegration rate has an exponential relationship with the combined water saturation, and it decreases as the combined water saturation increases, with a correlation coefficient of 0.9934.  
disintegration; red clay; moisture content; void ratio; NMR testing 20242024202420242024202420242024202420242020242024202420202420202420202420202420202420202420202420202420202420202420202420202420242020242024202024202420202420242024202  
Therefore, this paper aims to investigate the disintegration characteristics of Guilin red clay under the coupled conditions of moisture content and void ratio. Soil structure is an important characteristic of soil, which determines the physical, mechanical, and other properties of the soil [12]. [PERSON] et al. [13], [PERSON] et al. [14], and [PERSON] et al. [15] have found that soil structure has a significant impact on the disintegration characteristics of red clay, granite residual soil, and loess, neglecting the influence of moisture content on the disintegration of red clay. [PERSON] [16] and [PERSON] et al. [17] considered that the variation in rock moisture content is a controlling factor for disintegration, without considering the influence of the structure of the rock and soil on the disintegration. [PERSON] et al. [18] considered that the soil disintegration rate is closely related to the initial moisture content. [PERSON] et al. [19] and [PERSON] et al. [20] investigated the impact of varying moisture levels on the disintegration of Guilin red clay and granite residual soil. However, they did not adequately consider the pore structure of the soil-rock mass. [PERSON] et al. [21], [PERSON] et al. [22], [PERSON] et al. [23], and [PERSON] et al. [24] have conducted experimental studies on the disintegration characteristics of granite, red clay, purple soil, and sandstone particle soil under different initial moisture contents and compactions.