# Study of Load Calculation Models for Anti-Sliding Short Piles Using Finite Difference Method
## 4 Data Comparison
### Shear Force Comparison  
Figure 17 illustrates a comparison between the calculated model and the model test results for pile shear forces under loads of 20 kPa, 40 kPa, and 60 kPa. The shear force in the anti-sliding pile exhibits an upward trend with increasing load. The shear force at the maximum bending point, both above and below the sliding surface, is zero. In proximity to the sliding surface, the shear force experiences a rapid increase, and the maximum shear force of the anti-sliding pile is observed near the sliding surface, with a point of inflection in shear force occurring at the sliding surface. The variation of shear force with depth exhibits a close resemblance between the finite difference calculation model for anti-sliding short piles and the model test results, with a minimal margin of error. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Load (kpa)** & \begin{tabular}{c} **Numerical** \\ **Value (N-m)** \\ \end{tabular} & \begin{tabular}{c} **Distance from Sliding** \\ **Surface (cm)** \\ \end{tabular} & **Error** \\ \hline \multirow{4}{*}{20} & Calculated Value & \begin{tabular}{c} Positive Bending Moment \\ Negative Bending Moment \\ Positive Bending Moment \\ Negative Bending Moment \\ Positive Bending Moment \\ Negative Bending Moment \\ Positive Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ \end{tabular} & 572 & 20 & \multirow{4}{*}{5.0\%} \\  & \begin{tabular}{c} 5.0\% \\ \end{tabular} \\  & Experimental Value & \begin{tabular}{c} Positive Bending Moment \\ Negative Bending Moment \\ Positive Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ \end{tabular} & 748 & 20 & \multirow{4}{*}{12.4\%} \\  & \
\begin{tabular}{c} 12.4\% \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ \end{tabular} & 750 & 22.3 & \multirow{4}{*}{3.3\%} \\ \multirow{4}{*}{60} & Calculated Value &
\begin{tabular}{c} Positive Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ Negative Bending Moment \\ \end{tabular} & 747 & 21.6 & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Maximum bending moment values under different loads. Figure 16: Comparison of pile bending moment under different loads. Table 4 reveals that when comparing the moment values obtained from model tests with the shear force values calculated in this article, (1) shear force values measured in model tests under various loading conditions consistently exceed those obtained from the calculation model, showing an overall tendency to be higher, and (2) minimum shear force values universally occur in the section of the anti-slide short pile under load, and the shear force variation trend in this section exceeds that in the embedded section. The numerical values of the maximum positive and negative shear forces within the pile body closely match the calculated values, with a relative error of approximately 8.8%. In summary, the finite difference calculations for shear forces in anti-slide short piles exhibit strong alignment with experimental results. A comparison between the calculated model and the model test results for displacement, moment, and shear force reveals that the error values fall within a narrow range, and the trends are consistent. Thus, the calculated model for anti-sliding short piles developed in this paper is suitable for engineering design calculations. An analysis of the disparities between the model test values and the values obtained from the finite difference calculation model reveals several contributing factors:  
The choice of the finite difference segment length (\(h\)) impacts the accuracy of the calculation results. For enhanced precision, the segment length should be minimized in future analyses.