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Based on the consolidated undrained test under cyclic loading, the mechanical response of fiber-reinforced sand under cyclic loading was studied by varying fiber content (0.2% and 0.4%), fiber length (7 mm and 13 mm), and cyclic stress ratio (0.22, 0.24 and 0.26), and the effects of fiber content and fiber length on the excess pore water pressure, dynamic strength and dynamic shear modulus were discussed. The results showed that with the increasing of fiber content, the dynamic strength and liquefaction resistance increased, whereas the accumulation rate of excess pore water pressure decreased. The reduction rate of dynamic shear modulus decreased with the increasing of fiber length, and the dynamic strength decreased with the increasing of cyclic stress ratio, which indicated that the dynamic characteristics of fiber-reinforced sand were better than that of unreinforced sand.

The drained triaxial creep tests were carriedout to investigate the relationshipsbetween axial strain and time, axial strain and deviatoricstress, and axial strain rate and time for the undisturbed samples of muddy clay and clay in Tianjin.Based on the creep test results, the Singh-Mitchell modelwas used for creep calculation. The results showed that the muddyclay and clay exhibited typical non-linear creep properties. The axial strain increasedwith time and then gradually tendedto be stable.The strain rate increasedasthe deviatoric stress increased, and the muddy clay and clay showedthe characteristics of attenuation creep under deviatoricstresses. The axial strain of muddy clay wassignificantly larger than that of clay, and reachedthestable state within 3000 minutes.Under low deviatoricstress, the slope of the isochronal curve was smaller; while under high deviatoric stress, the slope of the isochronal curve waslarger.The test results were in good agreement with the calculation results, which indicated that the Singh-Mitchell model wassuitable for describing the creep behaviorsof the undisturbed claysin Tianjin.