## 4 Conclusions  
The characteristics of deformation and damping of the sandy and silty clay EPS beads-mixed lightweight soil were investigated, regarding the axial accumulative strain, resilient modulus, and damping ratio under different confining pressures and cement contents. The main conclusions are as follows:  
Figure 11: The damping ratio versus axial total strain under different condition: (**a**) Silty lightweight soil with \(a_{w}=14\%\); (**b**) Sandy lightweight soil with \(\sigma_{3}=100\) kPa; (**c**) Under \(a_{w}=14\%\) and \(\sigma_{3}=50\) kPa; and, (**d**) Comparison with [PERSON] et al.’s results.  
1. Within a certain range of confining pressure, cement content, and strain level, the ratio of axial cumulative strain to axial total strain, which is less affected by soil category and loading factor, remains at a constant value. A linear relationship between the two can be deduced and the formula for resilient modulus can be derived indirectly.
2. The springback deformation of EPS beads-mixed lightweight soil mainly comes from the springback deformation of the EPS particles. Due to the particularity of the lightweight soil, the confining pressure will cause certain damage to the cemented structure of the specimen, reducing the restriction on EPS particles but increasing the constraint on the specimen at the same time. However, the comprehensive effect depends on the strain level and the confining pressure.
3. The resilient modulus of the EPS beads-mixed lightweight soil decreases with the increasing axial total strain and increases with the increasing confining pressure and cement content. When the axial total strain exceeds 8%, the resilient modulus of the sandy lightweight soil is smaller than the silty clay lightweight soil. However, when the axial total strain is smaller than 8%, the opposite results can be observed.
4. The damping ratio of the EPS lightweight soil increases with the increasing axial total strain but decreases with the increasing confining pressure and cement content. Although the damping ratio of the sandy lightweight soil is smaller than that of the silty lightweight soil, the variation and difference are very small, and its value remains stable at around 0.07 to 0.08.  
Conceptualization, W.L., L.M. and J.Z.; methodology, W.L.; software, Y.Z.; validation, W.L. and L.M.; formal analysis, J.Z.; investigation, W.L.; resources and data curation, L.M.; writing--original draft preparation and writing--review and editing, W.L. and J.Z.; supervision, J.L.  
This research was funded by the National Key Research and Development Program of China (Grant No. 2017 YFC0805307), National Natural Science Foundation of China (Grant No. 51508279, 51578292, 51478054 and 51878078), Jiangsu Provincial Natural Science Fund Projects (Grant No. BK20150885), Excellent Youth Foundation of Natural Science Foundation of Hunan Province (Grant No. 2018J1026) Key Project of Education Department of Hunan Province (Grant No. 17A008). Open Research Fund of Science and Technology Innovation Platform of State Engineering Laboratory of Highway Maintenance Technology Changsha University of Science & Technology (Grant No. kj150103), Ministry of Housing and Urban-Rural Development of China (2018-K4-008) and Open Fund of National Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology (Grant No. kj170101).  
The authors still wish to thank the graduate students at who helped with specimen preparing and testing.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.