2W. S Tam and S. F Brown. Back - analyses elastic stiffness:comparison between different evaluation procedures [ A ] . First International symposium of Nondestructive Testing of Pavements and Back - calculation of Module [ C ]. Maryland : Baltimore, 1988, (6) : 29 - 30.
7MAGNUSON A H, LYTI'ON R L. Development of dynamic analysis techniques for falling weight deflectometer data [ R ]. Research Report 1175-2, TX. college station: Texas Transpor- tation Institute ,Texas A&M University ,College Station, 1997.