Monte Carlo simulates the light migration in compacted subgrade

Transmission characteristics of photon in the subgrade tissue is the theoretical basis of using laser imaging to detect density of compacted subgrade. After explaining the basic methods of using Monte Carlo simulation theory to study the propagation of photon in the subgrade tissue, the paper selects optical properties of several subgrade tissues, simulates the propagation of photon in the subgrade tissue by using program written with C language and presents the photon density in different radius with the light source as the center. Research shows that applying Monte Carlo to study the propagation of photon in the subgrade tissue is of great help to find out the factors which will affect the detection accuracy of non-destructive testing in principle.