In order to study the efficient and reasonable dynamic moduli testing technology of subgrade

based on analysis of the portable seismic property analyzer(PSPA) for its working principle and testing characteristics

the testing principle of PSPA is described; and the calculation formula of dynamic moduli is deduced according to the elastodynamics and spectral analysis of surface wave theory (SASW). Combined with the actual working conditions of subgrade field testing

the testing procedures and the main technical points of PSPA are put forward

and the distance between two detectors or detector with emission source of PSPA are both recommended according the different depths testing for subgrade. Combined with the project

a large number of on-site comparing tests on subgrade are made to obtain the dynamic moduli of PSPA

dynamic moduli of PFWD

resilient moduli of bearing plate

penetration ratios of dynamic cone penetrometer (DCP); and compactnesses of sand cone method in order by point to point

the correlation between dynamic moduli of PSPA and other indexes are established. The results show that all the absolute values of correlation coefficient are more than 0.80 to indicate the good correlativity existing between the testing results with PSPA and other testing methods

it means that using PSPA for rapid testing dynamic moduli of subgrade is reasonable and feasible

it can apply to the quality control in construction procedure of subgrade and provide reliable parameters and basis for pavement design.