With the rapid development of highway and runway construction and the widely application of silty sand subgrade

the stability of silty sand subgrade under aircraft loads should be further studied. Based on Byrne model describing the variation of pore pressure in saturated silty sand

the Lagrange difference method was introduced to analyze the effect of aircraft loading on silty sand subgrade pore pressure

displacement and instantaneous destroyed areas. The laboratory model tests were carried out to validate its rationality. Results show that the excess pore water pressure

displacement distribution and stress state in silt sand subgrade are influenced significantly by loading frequency

loading time and load peak

especially

loading frequency 5 Hz is a key control indictor and should be given consideration in the design.