Influences of different modifiers on the disintegration of improved granite residual soil under wet and dry cycles

Relationship between Disintegration Characteristics and Intergranular Suction in Red Soil

“…Under conditions such as rainfall (water), water gradually intrudes into the soil, dissolves some of the cementation between particles (mineral composition) and compresses the air in the pores to produce pore gas pressure (suction). Due to the effect of the expansive force generated by pore gas pressure and the expansive force generated by mineral composition, the size and order of soil particles (microstructure) change greatly [95]. When water enters unevenly into pores or fissures, the rate of thickening in the intergranular diffusion layer is not uniform, so the repulsive forces exceed the suction in different places between the grains, which causes the soil to disintegrate along the surface where the repulsive forces exceed the maximum suction.…”

“…that is, the anti-disintegrating force is greater than the disintegrating force, the soil sample remains intact and does not disintegrate. When F 1 + F 5 < F 2 + F 3 + F 4 + F 6 , that is, the anti-disintegrating force is less than the disintegrating force, the soil sample maintains integrity and disintegrates [95]. 2019) used an analogous sand-bath method to investigate the effects of wet-dry cycles and acid rain on soil disintegration characteristics [100].…”

“…Water rapidly occupies the internal pores of the soil, and thus, the air inside the soil is extruded in the form of bubbles to form external pressure [97]. By testing intergranular suction, including absorbed and structure suctions, Sun et al (2020) noted that the absorbed suction first increases and later decreases; nevertheless, a ripple crest occurs with the increase in the moisture content [56,95]. The variable structure suction increases with an increase in moisture content; however, the intrinsic structure suction remains constant.…”

“…Disintegrating force: f 1 is the component of the parcel force of the shrinkage film; f 2 is the component of the swelling force due to mineral composition; f 3 is the component of buoyancy; f 4 is the component of the swelling force due to pore gas; f 5 is the component of the cementing force; and f 6 is the component of gravity. F 1 , F 2 , F 3 , F 4 , F 5 , and F 6 are, respectively, the resultant forces of f 1 , f 2 , f 3 , f 4 , f 5 , and f 6[95].…”

Experimental Study on Disintegration of Guilin Red Clay

“…Shang ML compared the pH and oxide concentration of red clay before and after the disintegration of red clay and found through indoor model tests that the degree of disintegration of red clay increased with the decrease in the pH value of acid rain [1]. In the study of the disintegration of granite residual soil, different scholars have explored its disintegration process through different methods, and the dry and wet cycle test of granite residual soil with different improvers was carried out; the five stages of disintegration are summarized; the disintegration of different curing agents on granite residual soil is different, and in the observation of microstructure changes, the dry and wet cycle will break the cementation effect of particles between soil bodies, weaken the connection between particles, accelerate the disintegration rate of soil masses, and dry density has little effect on the disintegration of granite residual soil, moisture content, and temperature will significantly increase the disintegration of granite residual soil [2][3][4]. In the study of the disintegration of consolidated violet, the moisture content of the soil is strongly correlated with the disintegration speed, and through more detailed analysis, it is found that the disintegration of purple soil is mainly related to the dissolution of the gel material, the water absorption expansion of montmorillonite, and the thickness of electric double layer [5].…”