# An Investigation into the Influence of Sample Height on the Consolidation Behaviour of Dredged Silt
## 3 Test Results and Analysis
### Comparative Analysis of Consolidation Coefficient between Dredged Silt and Marine Silt  
Silt samples from identical regions, specifically dredged silt and marine silt (refer to Table 1), were examined. Table 5 delineates the physical attributes of both silt types along with the associated consolidation pressures. Both types presented similar initial water content and void ratios. These were analysed to determine variations in the consolidation coefficient and permeability coefficient in relation to consolidation pressure. The GDS consolidation device was employed for both consolidation and permeability tests to calculate these coefficients. Marine silt was sourced from a depth of 2 m in the shallow waters adjacent to the west channel port of Shenzhen Bay, and the test process and test results were described by [PERSON] [44]. In contrast, the dredged silt originated from 0.5 to 1.5 m depths  
Figure 9: Consolidation coefficients of samples with different heights under different consolidation pressures. atop the silt pond within Shenzhen airport's reclamation zone, and the test results were presented in [PERSON]'s study [45]. Additionally, [PERSON] et al. [16] conducted particle analysis tests on three types of silt samples and tested the composition of clay minerals by X-ray diffraction method. The outcomes are presented in Table 6.  
Figure 10 depicts the consolidation coefficient's fluctuation as a function of consolidation pressure across the three silt types. Observations from Figure 10 include:  
1. The consistency between the curves representing the consolidation coefficient of dredged silt from Shenzhen Qianwan and Shenzhen Airport suggests the reliability of the different consolidation devices employed. As the consolidation pressure amplified, the consolidation coefficient of dredged silt followed suit. Specifically, below or at 200 kPa, it continually rose in proportion to the intensifying consolidation pressure. For instance, under a preloading load ranging from 50 to 300 kPa, the coefficient surged from 0.263 \(\times\) 10\({}^{-3}\) cm\({}^{2}\)/s to 0.510 \(\times\) 10\({}^{-3}\) cm\({}^{2}\)/s. This doubling emphasizes the potential inaccuracies if one were to use a static consolidation coefficient for predicting settlement progression and consolidation intensity. 2. At pressures less than or equal to 200 kPa, marine silt's consolidation coefficient significantly surpassed that of the two dredged silt types. As this pressure escalated, the disparity between the silts diminished, eventually converging at a singular point. At a consolidation pressure of 600 kPa, the dredged silt's coefficient outperformed that of marine silt. These findings highlight the inferior initial consolidation properties of dredged silt. However, post-preloading treatment, it can either match or surpass marine silt's drainage consolidation rate. The distinction between the consolidation coefficients of dredged and marine silt is rooted in their formation mechanisms, stress histories, and compositional differences. Dredged silt emerges from undisturbed marine silt subjected to aerating and mechanical agitation, leading to under-consolidated soil. This disruption alters the initial soil structure into a looser form, characterised by unstable turbidity and granular patterns. These features contrast with the marine silt's predominantly granular bonding and honeycomb formations. The test results in Table 6 reveal that the marine silt in Shenzhen is dominated by kaolinite,