## 5 Conclusions  
This study explores the variations in the bearing characteristics of frozen sandy soils under different temperatures (\(T\)), moisture contents (\(\omega\)), and compaction degrees (\(K\)) through indoor CPT and CBR tests, establishing evaluation standards for the bearing capacity of frozen sandy soils based on the correlation between CPT and CBR values. The main conclusions are as follows:  
1. With constant \(T\) and \(\omega\), the CBR value of the soil sample increases with the increase in \(K\), but the rate of increase slows down. With consistent \(\omega\) and \(K\), within a temperature range from 0 \({}^{\circ}\)C to \(-\)3.1 \({}^{\circ}\)C, for every 1 \({}^{\circ}\)C decrease in temperature, the CBR value of the soil sample increases by about 50%. Below \(-\)3.1 \({}^{\circ}\)C, the CBR value tends to stabilize. Under subzero conditions with consistent \(K\), within a moisture content range from 10% (\(\omega\)) to 40% (\(\omega\)), for every 10% increase in \(\omega\), the CBR value of the soil sample increases by about 40%. When the \(\omega\) exceeds 40%, the CBR value tends to stabilize.
2. With fixed \(T\) and \(\omega\), the \(q_{\rm c}\) of the soil sample increases with the increase in \(K\), and the larger the \(K\), the slower the growth trend. With consistent \(\omega\) and compacity degree (\(K\)), within a temperature range from 0 \({}^{\circ}\)C to \(-\)2.5 \({}^{\circ}\)C, for every 1 \({}^{\circ}\)C decrease in temperature, the \(q_{\rm c}\) increases by about 30%. Below \(-\)2.5 \({}^{\circ}\)C, the \(q_{\rm c}\) tends to stabilize. Under subzero conditions with consistent compaction, within a moisture content range from 10% (\(\omega\)) to 40% (\(\omega\)), the \(q_{\rm c}\) continues to increase, reaching its maximum growth rate when the \(\omega\) approaches the liquid limit. When the \(\omega\) exceeds 40%, the \(q_{\rm c}\) tends to stabilize.
3. There is a linear correlation between the \(q_{\rm c}\) of frozen sandy soils and the CBR values, satisfying the function (\(CBR_{\rm p}=0.57q_{\rm c}+0.35\)). Within a 20% accuracy level, the histogram distribution and log-normal distribution of the ratio of predicted CBR values to actual values account for 81% and 51.3%, respectively, indicating good prediction performance of CBR. Referring to the guidelines for high-grade highway subgrade fill materials and typical CBR values for soft soils, preliminary evaluation standards for the bearing capacity of frozen sandy soils using CPT technology are proposed, indicating that a \(q_{\rm c}\) greater than 7 MPa signifies strong bearing capacity.  
Conceptualization, B.T.; data curation, L.Q.; investigation, P.Z.; methodology, L.Q; project administration, P.Z. and L.L.; resources, B.T.; software, Y.H. and S.H.; validation, Y.H. and S.H.; visualization, H.W.; writing--original draft, H.W.; writing--review and editing, H.W. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the National Key Research and Development Program of China (Grant No. 2023 YFB2604800); the National Natural Science Foundation of China (Grant No. 52178427); the Beijing Natural Science Foundation (Grant No. 8222034) and the Tibet Autonomous Region Science and Technology Program Project (Grant No. XZ202401 JD0019).  
The details of the test data will be made available on request.  
The authors declare no conflicts of interest.