红石岩堰塞坝新堆积体动三轴试验研究OA北大核心CSTPCD

The new deposit body of Hongshiyan barrier dam is mainly composed of limestone and dolomite,and the gradation and density are very discrete.Meanwhile,results show that the new deposit body has the properties of viscous coarse-grained soil,and the static parameters show obvious dispersion,so it is necessary to study its dynamic properties to provide material data for transforming the barrier dam to a hydraulic project.In this paper,the dynamic shear modulus and damping ratio tests of the new accumulation were carried out by using the GDS dynamic triaxial instrument to study the dynamic stress-strain characteris-tics and its influencing factors.The test results showed that the dynamic shear modulus of the new deposit body decreased and the damping ratio increased with the increasing of shear strain.The dynamic characteristics of the new deposit were obviously affected by the confining pressure.The maximum dynamic shear modulus increased with the augment of confining pressure.Under the same shear strain,with the increase of the confining pressure,the dry density,the coarse particle content respectively,the dynamic shear modulus ratio all increased and the damping ratio all decreased.However,the new deposit body had more fine grain content,com-plex grain lithology and showed obvious difference in weathering degree,so it led to discrete dynamic characteristics that is obvi-ously different from the artificial dam rockfill material.