Field experimental study on temperature deformation law of improved aeolian sand embankment

The aeolian sand improved with cement was used as filler in the subgrade works of TLSG-3 bid section of passenger dedicated line from Tongliao to Xinmin north. In the process of embankment filling, a large number of transverse cracks appeared in the superficial layer of the embankment. In order to explore the mechanism of cracks and put forward treatment measures, a section of test embankment with a total length of 150 m was built on site. The embankment tests were divided into five sections, and the improved aeolian sand with different cement and clay content was used as the filler. The variation law of humidity, temperature and strain of improved aeolian sand embankment with different mixture ratio was analyzed under the influence of temperature. The soil moisture content of improved aeolian sand embankment generally decreases with the decrease of temperature, and then increases with the increase of temperature, but the change range is small. The temperature of the surface soil of the embankment is obviously affected by the temperature change, which generally changes with the temperature change, but it has obvious hysteresis. The temperature of the deep soil of the embankment is relatively less affected by the temperature. The strain of embankment soil in this section is mainly controlled by the change of soil temperature. The strain of embankment surface soil changes greatly. With the decrease of soil temperature, compression deformation first occurs, and then with the increase of soil temperature, compression deformation gradually decreases, and then turns to tensile deformation. The strain of the deep soil of the embankment changes little, so the cold shrinkage deformation of the surface soil of the embankment due to the decrease of temperature is the main reason for the shallow cracks of the embankment in the actual engineering construction. Among the five test sections, the embankment strain change range with the improved aeolian sand mixed with 5% cement and 5% clay as the filler is the smallest. Therefore, from the perspective of controlling the deformation of embankment soil, the ratio of improved aeolian sand mixed with 5% cement and 5% clay is better than other ratios. © 2023, Central South University Press. All rights reserved.