Study On Settlement Properties Of River Sand And Weathering Material Composite Roadbed

The paper was finished with the background of Qin-Lin highway construction. The Linyi city where the highway pass through were filling subgrade but the soil resources there, was scarce. There were a lot of river sand and weather material in the Linyi city, Therefore, the sand and weather material will become the best option. Therefore, study on road performance of sand and weather material could Enriched and developed the results of the field and ensured the quality and speeded up the construction.Representative of sand and weather material was chosen for particles gradation test, specific gravity test, mud content test, compaction test, capillary rise test, direct shear test and triaxial test in order to investigate the physical and mechanical properties of sand and weather material. Test results showed that sand and weather material has good road performance and were suitable for road fillings.In the regions where the highway pass through, it was chosen 220m road for test road. It was mainly used sand and weather material as filling materials, through different filling ways (pure sand, pure weather material and sand-weather material composite roadbed), compaction ways, compaction standards, drainage ways, up-sealing layer materials in order to determine the construction techniques of roadbed. During construction of test road, buried related components instrument in order to monitor the road settlement. FLAC3D software was used to investigate the deformation properties of roadbed in the three filling ways by the parameters through laboratory test. The factors of road height, filling rate and ground water level was also considered to investigate the impact on roadbed and the law of depositional deformation. It showed that the biggest settlement happened in the center of the embankment. The settlement of weather material embankment was biggest, composite embankment taken the second place and sand embankment had the least settlement. As the height of embankment increased, the settlement and settlement after of all three kind of roadbed increased. As the level of groundwater decreased and filling rate increased, the settlement and settlement after of all three kind of roadbed increased.It also used exponential curve, combined exponential curve, hyperbola and poisson curve models to fit and predict the measured data. Results showed that Combined exponential curve had the best fitting, hyperbola and poisson curve took the second place and exponential curve had the worst fitting effect.