## 1 Introduction
### Evaluation of Soil Disturbance  
Numerous scholars domestically and internationally [10; 11; 12; 13; 14; 15; 16] have conducted relevant research on the definition and evaluation of the disturbance degree of soil following sampling. Scholars have introduced a range of approaches to quantify the disturbance degree, utilizing indicators such as variations in pore water pressure, \(e-1 gp\) curves, and alterations in soil strength pre- and post-sampling. In this study, the disturbance degree is determined by two aspects: the reduction in unconfined compressive strength and the alterations in compressibility properties. Disturbance degree is quantified by the reduction in unconfined compressive strength [8], with the following formula:  
\[RD_{q}=\frac{q_{u}-q_{u}{}^{\prime}}{q_{u}} \tag{1}\]  
In the formula, \(RD\) is the disturbance degree defined by the strength characteristics of the soil, \(q_{u}\) is the unconfined compressive strength of the undisturbed soil, and \(q_{u}{}^{\prime}\) is the unconfined compressive strength of the disturbed soil. The closer the \(RD_{q}\) value is to 1, the greater the disturbance degree of the soil sample. Utilizing the compressibility properties to define the disturbance degree, [PERSON] [17] analyzed a large amount of consolidation test data and described the consolidation compression curve using a double logarithmic coordinate system of specific volume \(v=1+e\) and consolidation pressure \(p\). [PERSON] and [PERSON] [16] proposed the following calculation formula:  
\[RD_{s}=\frac{C_{clb}}{C_{clr}}\times 100\% \tag{2}\] \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Water Content** & **Natural Density** & **Dry Density** & **Specific Gravity Gs** & **Plasticity Index** & **Liquid Index** & **Void Ratio** & **Sensitivity** \\
**(w/\%)** & \(\rho\) (\(g\)/cm\({}^{3}\)) & \(\rho\) (\(g\)/cm\({}^{3}\)) & **(g\)/cm\({}^{3}\))** & **(g\({}_{\text{T}}\))** & **(I\({}_{\text{P}}\))** & **(I\({}_{\text{L}}\))** & **(e\)** & **(_Sr_** \\ \hline
47.22 & 1.74 & 1.18 & 2.72 & 25.83 & 0.81 & 1.29 & 4.01 \\ \hline \end{tabular}
\end{table} 
Table 1: Basic physical properties of Zhanjiang Formation structural clay (Adapted from Ref. [9]). where \(RD_{s}\) is the disturbance degree defined by the deformation characteristics of the soil, and \(C_{clb}\) is the compression index before yielding of the disturbed soil sample, which is the slope of the compression curve of the disturbed soil sample in the pre-yield stage. Meanwhile, \(C_{clr}\) is the compression index of the remolded soil sample, which is the slope of the compression curve of the remolded soil sample under the \(\ln(1+e)-\lg p\) coordinates. The closer the \(RD_{s}\) value is to 100%, the greater the disturbance degree of the soil sample. Unconfined compressive strength tests were conducted on the samples. The unconfined compressive strength of the undisturbed soil sample was 241.94 kPa. The results of the unconfined compressive strength test for the disturbed samples are shown in Table 2. The relationship between vibration frequency/duration and unconfined compressive strength is illustrated in Figure 1. It can be inferred that higher vibration frequencies correspond to lower sample strength at a fixed duration, and longer vibration durations result in lower strength at a constant frequency. Disturbed soil exhibits lower strength compared to undisturbed soil. One-dimensional consolidation compression tests were conducted on the samples, with results presented in Table 3. The \(e-\lg p\) curves under different test conditions are depicted in Figure 2a-c. The figures show that the undisturbed sample's compression curve is positioned above those of disturbed samples under all test conditions, exhibiting the longest linear segment extension. The void ratio of the samples decreases gradually with increasing vertical load. At a vertical load of 50 kPa, the rate of void ratio decrease accelerates; beyond 400 kPa, it declines sharply until reaching 3200 kPa.