The dynamic stress-strain and dynamic elastic modulus-strain of cemented soil mixed with different amount of polypropylene fiber or the basalt fiber were studied by using the dynamic triaxial apparatus. The results show that the dynamic strength and dynamic elastic modulus of cement soil is in connection with confining pressure

fiber types and fiber contents. With the increase of fiber contents

the dynamic strength and dynamic modulus of cemented soil increase

and the dynamic deformation decreases. The hysteresis curve and the microstructure of cemented soil show that the cement soil containing basalt fiber presents the best dynamic performance . The maximum dynamic elastic modulus increases with the increase of confining pressure and fiber content. The normalized curves of cemented soil mixed with basalt fiber under different confining pressures gather with each other

so the dependency on the confining pressure is weakened.