## 1 Introduction  
With the accelerating urbanization of China over recent years, the amount of waste slurry generated from projects such as port channel dredging, municipal dredging, and pile foundation construction has increased dramatically [1; 2]. According to statistics, hundreds of millions of cubic meters of waste slurry are produced in China annually, the extremely high water content of which presents significant challenges in terms of achieving solid/liquid separation. Notwithstanding this difficulty, waste slurry would severely contaminate the surrounding environment if discharged untreated [3]. Therefore, effective slurry treatment measures are critically needed [4; 5], with chemical flocculation currently ranking among the main methods to achieve efficient treatment and recycling of waste slurry [6]. Adding flocculants to the slurry modifies the surface properties of the suspended clay, which induces particle flocculation into flocs, thus accelerating sedimentation [7]. Currently, lime-based inorganic flocculants are often utilized in engineering to treat waste slurry [8; 9; 10]. A series of physicochemical reactions, including ion exchange reactions, volcanic ash reactions, and carbonation reactions, occur once lime is mixed with slurry [11; 12; 13]. Significant differences were observed in some studies in both the compressibility and permeability of the slurry before and after lime-based treatment and its dual effect, which were found directly to affect the subsequent dewatering process [14; 15]. In recent years, various researchers studied the compressibility and permeability of lime-stabilized soils. [PERSON] and [PERSON] [16] used lime to stabilize marine clay on the Madras coast of India, and their test results showed that lime could effectively reduce the compressibility of clay, reducing its coefficient to between only half to one-third of that of untreated soil samples. [PERSON] [17] compared and analyzed the compressibility of different granular gradations of the slurry with a 2% lime dosage. His results established that the clay particle content significantly affected the compressibility of the soil samples after lime stabilization. [PERSON] et al. [18] preliminarily explored the effects of water content and lime dosage on the permeability of soil samples. [PERSON] et al. [19] investigated the permeability of lime-stabilized soil samples with initial water contents of 122% and 650% by consolidation/permeability tests. It was shown that the optimal lime dosage for soil samples with both initial water contents was 3%. [PERSON] and [PERSON] [20] used a flexible wall permeameter to explore the permeability of lime-stabilized dredged slurry with an initial water content ranging from 110% to 160%. They established that the permeability of lime-stabilized soil decreased once the lime dosage exceeded 4% and found that the incidence in pores smaller than 1 um increased significantly after lime treatment. [PERSON] et al. [21] analyzed the soil pore change trend before and after lime stabilization by comparing pore sizes with mercury intrusion porosimetry (MIP). Their test results showed that a large number of new pores smaller than 0.3 um had formed in lime-stabilized soil, which were not present in the remolded soil samples. [PERSON] et al. [22] examined the structure of lime-stabilized flocs by scanning electron microscopy (SEM) and found a significant increase in the intergranular accumulation layer. The mechanism of the effects of lime on the compressibility and permeability of a high water content slurry has not been elucidated in existing studies, leading to engineering problems such as wide variations in stabilized slurry performance in different areas and difficulties in determining the optimal content of curing agent. In light of the above, the present study investigated the compressibility and permeability of lime-stabilized slurry with different granular gradations.