Device and method for health diagnosis of subgrade service performance

A device for health diagnosis of subgrade service performance, comprising:

• a loading device, configured to apply a load to a road;
• a data acquisition device, configured to collect stress and a vertical displacement of a pavement layer of the road when the load is applied to the road;
• a data analysis device, configured to
• perform a frequency spectrum analysis on a signal of the vertical displacement to obtain a propagation speed of a Rayleigh wave in a pavement layer of the road and a thickness of the pavement layer of the road, and obtain an elastic modulus of the pavement layer of the road according to the propagation speed of the Rayleigh wave;
• obtain an elastic modulus of a subgrade soil of the road by inputting the stress, the vertical displacement, the elastic modulus of the pavement layer of the road and the thickness of the pavement layer of the road into a trained subgrade soil modulus calculation model;
• obtain a dynamic deformation value of the subgrade of the road under a standard load according to the elastic modulus of the pavement layer of the road, the elastic modulus of the subgrade soil of the road and the thickness of the pavement layer of the road;
• and
• evaluate a health state of the subgrade of the road according to the dynamic deformation value of the subgrade of the road under the standard load.