Abstract: The dynamic stress-dynamic strain relationship is an important parameter reflecting the dynamic characteristics of subgrade filling soil, and the experimental study of its influencing factors can provide a reference for the engineering characteristics of subgrade filling soil. In this paper, the authors use the dynamic triaxial test method to study the influence factors of gravel-like soil, adopt the stress-controlled loading method to load, analyze five conditions such as test pressure, soil sample moisture content, soil sample compressibility, load frequency,and initial static deviatoric stresses of gravel-like soil, and also summarize the dynamic stress-strain relationship change law of gravel-like soil. The research results show that:1) When the pressure of the dynamic triaxial test is 30 kPa, the compaction of the soil sample is 96%, and the optimal moisture content is 7.5%. The dynamic stress-dynamic strain relationship curve is closer to the stress axis, and the dynamic strength of gravel-like soil is great; 2) When the load frequency changes between 1 and 2 Hz, the initial static deviator stress (less than 10 kPa) has little effect on the dynamic stress-strain relationship of gravel-like soil; 3) The fitting correlation coefficients of the dynamic stress-dynamic strain relationship curve to the hyperbolic model used are all greater than 0.96, indicating that the model can effectively fit the relationship curve; 4) Based on the test model, the greater the pressure in the test, the smaller the values of the parameters a and b; similarly, the greater the compression of the soil sample, the smaller the values of a and b.

Key words: gravel soil, dynamic triaxial test, dynamic stress-dynamic strain, influence factors